Fleabane, onion weed and other pest plants in Erskine

Since moving to Erskine (a suburb of Mandurah in Western Australia) from South Australia I couldn't help noticing the fleabane (Erigeron species) growing as weeds adjacent to paths in, and in the vicinity of, the Len Howard Conservation Park.

Only a little later I became aware that dune onion weed (Trachyandra divaricata) was widespread. Fleabane is an annual weed, onion weed is a perennial.

In November 2022 I noticed Maltese cockspur (Centaurea melitensis) in the Len Howard Conservation park. There are also some black nightshade (Solanum nigrum) plants scattered about; I usually pull these out whenever I come across them. I have given a high priority to removing Caltrop (Tribulus terrestris) because it is relatively rare and a terrible weed.

Curiously, many of the parks in the Erskine area are very well looked after with hardly a weed to be seen. A few are relatively neglected.

Our shared natural environment has always been a great concern of mine. I try to do what little I can to help preserve it.

In my previous life in SA I have worked at controlling or eradicating pepper trees, Aleppo pines and many other weeds as well as at reintroducing native plants to roadsides and several other areas. (See revegetation work, Gleeson Wetlands and Crystal Brook's Central Park.)

So I have decided to make a project of removing these weed species in particular and making other improvements to the shared local environment.

This page was written 2022/03/05, last edited May 2023
Contact: David K. Clarke – ©

This is a work
in progress

This page has evolved with my work on controlling invasive weeds. If I was to write it again it would be arranged more logically.


The six photos below show how fleabane has invaded reserves in and near Mandurah. I am making an effort to control it near where I live. These photos were taken in places beyond the limited area that I can reasonably hope to look after. I find it sad that in a city of 100,000 people practically none wants to make any effort to control the weeds in our beautiful parks.

Fleabane in Tamworth Hill Swamp Reserve
Fleabane in Tamworth Hill Swamp
Fleabane in Marlee Reserve
Marlee Reserve is too far from my home for me to attempt to control the fleabane in it.
Photographed 2022/11/15, iPhone 11 Pro, standard lens
Fleabane has been allowed to get thoroughly out of control in Tamworth Hill Swamp reserve at Baldivis, 30 kilometres to the north of Erskine (photo on the right, taken 2022/03/02). It would be disastrous to the Len Howard Conservation Park if it was allowed to similarly colonise the area here.

I saw plants around three metres tall in the Tamworth Hill Swamp Reserve. Apparently conditions there are ideal for the growth of the weed; conditions in parts of the Len Howard Reserve would be much the same.

Fleabane, the Erigeron genus was until 2020 named Conyza. It seems that there are at least two, and possibly three species in the area: E. Alba, tall or smooth fleabane; E. bonariensis, flaxleaf fleabane; and possibly E. sumatrensis, broadleaf or Guernsey fleabane.

Dune onion weed (Trachyandra divaricata) is also in major pest plant proportions in some of the more neglected areas. (Alternative common names are false onion weed, strapweed and simply onion weed.)

Coodanup Foreshore Reserve
Coodanup Foreshore Reserve Coodanup Foreshore Reserve
Coodanup Foreshore Reserve Coodanup Foreshore Reserve
The four photos above, all taken in the Coodanup Foreshore Reserve, show how badly fleabane can spread in the Mandurah area (and probably in the Perth Coastal Plain generally) if no action is taken to control it.

The fence is to keep cats and foxes out of the reserve - a commendable aim.

Photos, iPhone 11 pro, standard lens, 2023/03/11

Government action?

There's fleabane even in Perth's iconic Kings Park
Fleabane in Kings Park
The photo on the right shows fleabane plants in Kings Park, photographed on 2023/02/23. I had seen a few fleabane plants in Kings Park on previous visits, this was perhaps the most advanced plants that I've seen there - and there were half a dozen or so in this very small part of the Botanic Garden area.

This invasive weed is becoming more and more widespread, problematic and conspicuous in the Perth-Mandurah area and in agricultural areas.

I would think that in the case of Mandurah at least Council could consider making it mandatory for people to remove fleabane from the verges in front of their houses. This would greatly reduce the amount of seed blowing around and could eliminate fleabane from Mandurah all together. Perhaps the WA state government should encourage councils to do so?

My fleabane removal project

Len Howard Conservation Park
The area that I am working on includes reserves and adjacent paths south of Old Coast Road within a kilometre or two of my home, including part of the Len Howard CP.
Area of concern
The Len Howard Conservation Park (LHCP), I believe, is roughly the brown strip running from bottom centre to the upper right of this Google Earth image. Mandurah Quay is in the upper right corner of the image (at the word 'Boundary'). There is an unsealed walking path that runs from the Car Park and Nature's Eye Shelter (bottom, left of centre) along near the coast of Collins Pool to Mandurah Quay. There are concreted walking/cycling paths on the northern boundary of the conservation park.

The inner part of what I've labelled the big ephemeral swamp on the image (more accurately the big seasonal paperbark swamp, BSPS) is the responsibility of the Parks and Wildlife Service, while the outer, more open parts that can be mown, are council responsibility.

Tall fleabane in the BSPS
Tall fleabane in BSPS
Interestingly there are three types of occurrence of fleabane: scattered small plants, crowds of small plants, and areas of a limited number of tall plants, such as in this photo. A photo of an crowd of small plants is shown below.
That's me in the photo.
Photo: iPhone 11 pro, 2023/01/18
My wife and I moved to Erskine in early February 2022 to share a house with our daughter and her family.

At the time I started writing this page I had decided to make a project of trying to progressively remove, by hand pulling, fleabane from the Len Howard Conservation Park and its vicinity, at least within a kilometre or so of our home.

I notified council and the Department of Biodiversity, Conservation and Attractions (DBCA) of my intention on 2022/03/06. Neither had replied by 2022/03/21, but I noticed on that day that at least some of the fleabane around the big (unnamed?) seasonal paperbark tree swamp on the eastern side of Bridgewater Lifestyle Village had been sprayed using a green marker dye and, presumably, a herbicide. Could there be any connection between my informing DBCA about the fleabane problem and the spraying?

By July 2022 I had achieved a fair degree of success in removing visible plants within a kilometre of home.

The big seasonal paperbark tree swamp, which I often shorten to BSPS on this page, is just over a kilometre from my home by the two shortest routs available to me. Removing fleabane (and false onion weed) from the BSPS had turned out to be by far the biggest part of my project by early 2023.

At the start, Late February 2022

Fleabane plants
These fleabane plants were on Redfern Place. Click on the image to see more detail of the seed head. Image 2022/03/06
There was fleabane:
  • on the sides of the shared trails:
    • from the Novara boat ramp along Dampier Avenue;
    • along the (short) extent of Glendart Court;
    • along Silverton Crescent where it bordered the conservation park;
    • along Len Howard Drive South to the big seasonal paperback tree swamp;
    • in the adjacent park lands.
  • There was scattered fleabane along sections of the walking trail through the Len Howard Conservation Park;
  • there were fairly extensive patches of the weed in the southeastern section of the big seasonal swamp, near the shared paths, as well as in the northern extremity.
  • there was a very bad, dense outbreak of fleabane surrounding the walking trail turnoff to the bird hide.
  • There was fleabane in all of the project areas I adopted.
In most of these places there were also scattered onion weed plants. At the northern end of the BSPS onion weed was dense in a number of places, especially close to Len Howard Drive and Oakleigh Drive (the areas of the BSPS that are Council's responsibility).

Update, December 2022 In the spring of 2022 there was a germination of many thousands of fleabane plants in the area that I had adopted. By the end of the year I thought I was getting them under some level of control, but in late February 2023 I was still working at them.

Update late March 2023, there were very few fleabane or onion weed plants to be seen in all the project areas I had adopted. My rough summing indicated that I had dug out over 20,000 onion weed plants.

A beautiful place that deserves to be looked after


A pond in the Len Howard Conservation Park; I have called it the Duck Pond. The water birds in the middle distance are Pacific black ducks (Anas superciliosa, they can be identified by the black steak through the eye area), at least some of those in the distance are grey teal (Anas gracilis).

At another time I estimated that there were 300 ducks on this pond. They are very wary and fly off as soon as they see a nearby person.

Photo Canon Ixus 190, 2022/02/22

This patch of fleabane was in the southern part of the big seasonal paperbark reserve. Note that it is on a slight mound; I suspect that the surrounding area is seasonally flooded and that this kills any fleabane seeds in the soil.
This patch, which is one of many but denser than most, was sprayed on 2023/01/05, the same day I took the photo.

Progress on fleabane

This section added
By late March 2022 I had pulled out most of the live plants along the shared path between the Novara boat ramp and the southern side of the big seasonal swamp. Of course there will be another crop when the seeds remaining in the ground germinate.

As mentioned above, someone, presumably from the Mandurah City Council, had sprayed some of the fleabane in the big seasonal paperbark swamp area around 2022/03/20. It would have been better done a month or two earlier, before seed-set, but better late than never.

Comment added
There are now (June 2022) very few fleabane plants in, and on the paths adjacent to, the Len Howard Conservation Park within a kilometre of my home. I have recently been putting in some time removing what were numerous fleabane plants in the big paperbark swamp area.

This section added
From July I saw very few fleabane plants in the area that I had adopted. I concentrated on onion weed from then for the following few months. Fleabane started to become conspicuous again in October 2022. By late October I had removed or killed most of the onion weed plants in my area - other than in the storm water sump (SWS) and in the Big Seasonal Paperbark Swamp (BSPS).

I didn't start keeping any sort of detailed record of my work on fleabane until early October 2022.
  • 7th October, 83 fleabane, mostly on LHCP concrete footpath
    This section added
  • 26th, 37 in BSPS
  • 27th, 214, northern end and eastern side of BSPS
  • 3rd November, 10 W side, 30 N end

    Fleabane control methods

    With only a little care fleabane plants can usually be pulled out with most of their roots. If the ground is unusually hard sometimes just the top pulls off.

    When I pulled out significant numbers of plants that were setting seed I collected them up and put them in a bin or took them home, to stop the seed from having any chance to germinate.

    Methods I've used to control fleabane are:

    • Pulling out the Larger plants;
    • Hoeing the smaller plants except where they are in such great number that this is impractical;
    • Spraying with glyphosate where there are too many plants to make pulling out or hoeing viable.


    A woman came up to me when I was spraying fleabane plants and expressed her opinion of glyphosate with something like "that stuff should never be used, it's shockingly harmful". (I don't remember her exact words.)

    I have written elsewhere on this page about the reliable research on glyphosate toxicity.

    And I have written on other pages about my sources of information and where we should look for reliable information.

  • 5th, more fleabane pulled and/or hoed
  • 8th, something like 50 plants pulled or dug out near NW corner of BSPS
  • 17th, while working mainly on onion weed I dug out perhaps 30 fleabane plants at the northern end of the BSPS. There are a great many to be pulled or hoed out.
  • 50 fleabane pulled out BSPS.
  • 19th, sprayed about 200 very small fleabane plants beside the path in the morning, pulled out about 80 big plants in the afternoon, BSPS
  • 20th to 26th; pulled out and hoed out several hundred plants in BSPS. At about this time I stopped trying to count the fleabane plants that I killed.
  • 29th, sprayed hundreds of young fleabane plants over a 120m section of the path adjacent to Glendart Court
  • 1st December, 50 large fleabane pulled out, NE side of BSPS
  • 3rd, about 50 plants pulled or hoed out and perhaps 200 sprayed with glyphosate, S end of BSPS.
  • 4th, some fleabane pulled out of BSPS, N end. 15m outbreak of fleabane on Silverton adjacent LHCP and scattered fleabane adjacent path further east all sprayed.
  • 7th, about 50 by path adjacent LHCP
  • 8th, hundreds of fleabane plants sprayed adjacent to Glendart Court and also Len Howard Drive
  • 10th and 12th, fleabane sprayed at the northern end of BSPS, and a small patch beside the path adjacent to Dampier Avenue.
  • 13th, several hundred plants sprayed, BSPS mid NE;
  • 14th, 46 pulled out on Dampier
  • 16th, sprayed around W/S reserve
  • 17th, sprayed large infestation inside inner path, BSPS. Problematic because there are also ?native plants. This was one of the very few places where I had found a risk of off-target killing in spraying fleabane. Hoed and pulled fb on Silverton and Len Howard Drive;
  • 19th and 20th, hoed and hand pulled fleabane adjacent to Len Howard Drive, Silverton Crescent and Glendart Court
  • 21st, sprayed along the northern half of the path on the eastern side of the BSPS
  • 22nd, sprayed and hand pulled on the northern side of the path across the southern end of BSPS
  • 23rd, sprayed a patch at the NE corner of BSPS and some scattered plants
  • 24th, hoed and hand pulled scattered plants N end BSPS and a patch inside the path in the NW area of the BSPS
  • 25th, pulled and hoed fb N end BSPS inside paths
  • 26th, sprayed fb in same area
  • 28th, pulled and hoed fb on Len Howard Drive near BSPS
  • 29th, spayed fb west side BSPS, mainly adjacent road. Hand pulled a patch adjacent Dampier.
    A patch of young fleabane plants in the BSPS
    Fleabane patch - before
    Before hoeing
    While many of the fleabane plants I've come across have been scattered there has also been a number of 'clumps' of plants such as the above. In some cases I have sprayed such clumps with glyphosate, at other times I've just used a hoe.
    Fleabane patch - after
    The same patch as above, after hoeing
    Photos: iPhone 11 pro, standard lens, 2023/01/17
  • 20th, sprayed fb east side of BSPS, inside path. Hand pulled several hundred plants adjacent LHCP dirt path near back gate to Bridgewater Village. There were many small seedlings with lots mixed in with rushes - so I certainly didn't get them all.
  • 25th, pulled and hoed N end BSPS inside paths
  • 26th, sprayed fb in same area. 213 ow, N end, between paths
  • 29th, spayed fb west side BSPS, mainly adjacent road. Hand pulled a patch adjacent Dampier.
  • 31st, 210, ow S and N of BSPS. Hoed fb SW side ofBSPS.


    Fleabane, 2023

    While I'm still hoeing out onion weeds whenever I see them most of my time now is spent of fleabane eradication.
  • 2023, January 1st, pulled fb in BSPS
  • 2nd, sprayed fb, in extreme NW corner BSPS
  • 3rd, sprayed fb in bush area, in from the NW corner BSPS
  • 5th, sprayed fb in lightly bushed area inside southern path BSPS. Ran out of spray, will have to clean up remainder later.
  • 7th, Pulled and hoed fb while hoeing onion weed
  • 8th, pulled and hoed fb around the NE corner of the BSPS
  • 9th, pulled out and hoed around NE corner of BSPS. Also planted acacia saligna and hardenbergia comptoniana seeds
  • 10th, 100 or so pulled or dug out of W/S reserve
  • 11th, hoeing E side BSPS, W/S reserve
  • 12th, hoeing E side BSPS, seeding and hoeing W/S reserve
  • 13th, 100 minutes hoeing and pulling on BSPS.
  • 14th, sprayed plants in among branches of fallen tree, one hour hoeing and pulling around eastern and northern sides of BSPS
  • 15th, 1hr fb, N end BSPS. 1hr loop trail in LHCP
  • 16th, 15min near home, 35min cleaning up remains of big patch among scrub sprayed in S end BSPS
  • 17th, sprayed fb on loop path and adjacent road to car park in LHCP. 20 minutes hoeing in BSPS SW side
  • 18th, 50 minutes hoeing and pulling fb among trees in BSPS
  • 19th, 40 minutes hoeing and pulling among trees in W side of BSPS
  • 20th, 70 minutes mainly hoeing, N end of BSPS
  • 21st, 40 minutes hoeing and pulling among trees on E side of BSPS
  • 22nd, 45 minutes, E side and S end BSPS, and seeding. Anyone walking on the paths around the BSPS would now see very little fleabane. Hand pulled fb adjacent paths in LHCP.
  • 23rd, 75 minutes, NW and SE corners BSPS
  • 25th, 55 minutes, N end BSPS
  • 26th, 60 minutes, scattered NW corner BSPS.
  • 27th, 30 minutes fb, W side BSPS
  • 28th, spraying W side BSPS, in scrub
  • 30th, pulling and hoeing, E side of BSPS, including the lawned area
  • 31st, 20 minutes, pulling and hoeing, E side of BSPS, scattered plants
  • 2nd February 2023, morning, 40 minutes, pulling and hoeing, SW corner of BSPS among trees, one fair sized patch plus scattered. Evening, 30 minutes N end BSPS within ~40m of paths. On many days I pull out isolated fb plants whenever I happen to come across them.
  • 7th, hoed and pulled several hundred fb, in scrub, SW corner BSPS
  • 10th, sprayed 500 or more plants in scrub, western side BSPS - they were too numerous to hoe or pull.
  • 11th, 480 NW corner BSPS. Estimated more than a thousand remain - photo of a few
  • 13th, sprayed one or two thousand plants, NW area of scrub in BSPS
  • 14th, pm, over 200 hoed SW section BSPS in scrub. Of the many plants remaining I will have to wait to see which die due to being sprayed.
  • 15th, pulled out about 100 plants beside storm water sump (SWS; while picking up rubbish)
  • 17th, am, pulled out 20 or so plants while having a short inspection walk in BSPS; pm hoed and pulled over 100, NE corner of BSPS
  • 18th, couple hundred hoed out, N end BSPS

    Outbreak removed - only about 40 minutes work
    Fleabane outbreak Outbreak removed
    While the Novara Beach Reserve is well over a kilometre from my home it is a beautiful place in which I can have a significant impact on weeds with a moderate effort.

    This is the same outbreak as mentioned elsewhere on this page and in regard to the backward step of over-clearing path edges. Weeds are very good at colonising bared ground.

    This outbreak was in the northern end of the Novara Beach Reserve. The reserve had very little other fleabane - it would have been a great pity if this patch had been allowed to go to seed again in 2023.

    Photo and plant removal 2023/02/19.

  • 19th, several hundred pulled out beside path at northern end of Novara Beach Reserve (outside of my normal area, but very important to be done to stop this dense area from going to seed - there were very few outside of this infestation)
  • 20th, pulled out several hundred plants from the foreshore strip south of the Novara boat ramp into the northern half of the Novara Beach Reserve
  • 22nd, sprayed in among the trees, NW area of BSPS. Pulled another hundred or so plants in the area from the Novara boat ramp to Novara Beach Reserve.
  • 24th, pulled 87 scattered plants in grassed area E side of BSPS
  • 25th, hoed and pulled about 340 scattered plants E side of BSPS
  • 26th, hoed and pulled a couple of hundred on the E side of BSPS. I noticed that someone had been spaying fb using red marker dye.
    Dense fleabane patch against paving
    Fleabane Novara boat ramp area
    Adjacent the lagoon in the southern end of Novara boat ramp car park area. There were several areas where there were many fleabane plants but in most of the vegetated areas there were few or no fb plants; so it made sense to remove them all.

    Fleabane often grows immediately adjacent to a paved area. I suspect that the seeds blow along the ground until they come to the edge of the paving, come to rest there and later germinate.

    Photo iPhone 11 pro, standard lens, 2023/03/09

  • 1st March 2023; hoed in the northern end of the BSPS
  • 2nd, hoed in the northern end of the BSPS
  • 4th, hoed and pulled scattered plants around the BSPS and pulled about 50 from the walking trail in the Len Howard CP
  • 5th, about 50 pulled out at Osprey Waters Foreshore Reserve
  • 6th, about 30 pulled out in and adjacent to the WOGL reserve
  • 7th, one or two hundred hoed out in SW area of BSPS
  • 8th, a couple of hundred from path sides Novara Beach Reserve
  • 9th, several hundred sprayed (where too crowded to pull), several hundred pulled and binned (they had gone to seed, they came close to filling the bin), all at the western end of the Novara boat ramp car park (photo on right). In pm pulled out some fb and caltrop plants while picking up rubbish in the WOGL reserve and SWS.
  • 10th, pulled out about 20 against Old Coast Road, WOGL reserve. About 50 in BSPS in pm.
  • 11th, pulled out 57 northern end BSPS, about 20 adjacent Dampier Avenue and Dampier Court
  • 12th, pulled or hoed about 30 in BSPS and about 15 around SWS
  • 14th, about 50 plants WOGL reserve and adjacent SWS
  • 16th, about 250 hoed and pulled out BSPS
  • 21st, morning, about 40 hoed and pulled in scrub in BSPS. Afternoon, pulled out about 50 big plants in the Novara Foreshore Reserve. I was surprised I had not noticed them previously.
  • 23rd, hoed out several hundred scattered plants in the scrub on the western side of BSPS. I hoed out all I saw.
  • 25th, hoed and pulled about 100 near Novara boat ramp
  • 26th, pulled out 2, SWS
  • 28th, pulled about 6, SWS
  • 29th, about 20 from W/S Reserve
  • 30th, 20 from Novara Beach Reserve, 30 from bush inside BSPS
  • 31st, about 10 on path adjacent LHCP
  • April 1st, near path on E side of BSPS
  • 2nd, at least 200 pulled out at Osprey Waters
  • 3rd, about 100 pulled out at Osprey Waters Reserve, all yesterday's and today's that had gone to seed binned.
  • 4th couple hundred BSPS, scattered
  • 11th, scattered BSPS, 15 LHCP, various elsewhere
  • 12th, scattered plants various places
  • 13th, a few scattered around W/S reserve
  • 14th, about 40 N end BSPS
  • 24th some W/S reserve, more than a hundred BSPS
  • 26th, a very few scattered plants Glendart and Novara
  • 28th, about 30, Novara Foreshore Reserve
  • 30th, about 30, Osprey Waters Reserve, perhaps 20 adjacent the trail in LHCP
  • May 3rd, scattered, path adjacent LHCP, W/S reserve
  • From 4th to 9th I hoed or pulled out small numbers of plants in many locations in my area of activity.
  • 12th, pulled out 225 plants in Novara Beach Reserve
  • 19th, about 30 BSPS
  • 20th, scattered plants hoed in BSPS
  • 25th, pulled out about 30 plants at the western end of the Novara boat ramp car park

Also see the dune onion weed section, and the section on progress with the control of onion weed, on this page.

This section added

A backward step?

Over-cleared path
The section of the walking trail that is the subject of this note, and a small part of which is in the photo, is to the north of the big seasonal swamp and to the south of Mandurah Quay. The native vegetation on each side had been cut back heavily shortly before my wife and I walked it on 2022/03/28.


An example

Fleabane has taken advantage of native plants being cleared from the side of a path in Novara Beach Reserve where there was a localised dense outbreak in an area where there was otherwise very few of the weeds.
Opportunistic weeds - like fleabane, evening primrose and onion weed - will take full advantage of any bared ground. Excessive clearing of native vegetation, like this, is bound to give weeds a foothold.

Several hundred metres of the path was like this. In this section native sedges or rushes can be seen to have been heavily cut back to the left of the path, but the whole visible section, and far more, had been cleared for half a metre or more on each side of the path.

I suspect the intention of whoever did the clearing was to allow people to see any snakes that may be present. I've seen several snakes in or near the Len Howard Conservation Park, but they seem to be easily avoided. Surely the preservation of the native bush is more important than protecting people from the occasional close encounter with a snake.

In early May 2023 I noticed that trees near the trail through the western section of the Len Howard Conservation Park had been very recently trimmed back to make widen the trail. This would make it easier and more convenient for users, but again, at a cost to the remnant vegetation. Again, people have been put first, the environment second.

I have argued elsewhere, that if humanity is to have a future we must learn to put the environment first. We are nothing without a viable environment.

This all reminded me of when the Port Pirie Regional Council excessively and unnecessarily cut back remnant native vegetation on the roadsides near my old home.

This section added

Project areas

In the beginning I intended to try to remove all the fleabane in and adjacent to parks within about a kilometre of my home in Erskine. A little later I added the removal of false onion weed to fleabane. Later again I extended the area I worked on beyond a kilometre.

Definable areas I was working on by late February 2023 included - in approximate order of increasing distance from my home:

  1. The small unnamed reserve at the western junction of Wattleglen and Silverton (W/S Reserve)
    Scattered fleabane and particularly onion weed. Its area is about 7,000 square metres. As of the end of March 2023 I had dug out over 2000 onion weeds plants from this reserve.

  2. Part of the Len Howard Conservation Park (LHCP)
    Used frequently by walkers. There was a bad outbreak of onion weed at the car park, particularly around the information sign, and there was scattered fleabane and onion weed in many other places, including along the path adjacent to Len Howard Drive and Silverton Crescent. The part that I am trying to look after is to the west of the BSPS . The area of 'my' section is about 37 hectares, but much of it is inaccessible. As of the end of March 2023 I had dug out over 800 onion weeds plants from this reserve, most of them in the car park area.

    The area of LHCP east of the BSPS is badly infested with weeds, but is quite a distance from my home and perhaps beyond my ability to clean-up, at least for the present.

    Fleabane in Osprey Waters
    A section of one of only a couple of patches of bad fleabane outbreaks in the Osprey Waters reserve.

  3. The storm water sump reserve on Wattleglen Avenue (SWS)
    Given a low priority because it is not used by the public, but heavily infested with onion weed. Its area is about 11,000 square metres. As of the end of March 2023 I had dug out about 900 onion weeds plants from this reserve.

    In late April 2023 I sprayed several hundred onion weed plants.

  4. WOGL Reserve: The small unnamed reserve between Wattleglen Avenue, Old Coast Road, Galbraith Loop and Lloyd Crescent was added to my list on 2023/03/05, because it was in fairly good condition, with fairly few weeds and not far from my home. The area is about 5,400 square metres. As of the end of March 2023 I had dug out over 500 onion weeds plants from this reserve.

  5. Novara Foreshore Reserve;
    Around the Novara boat ramp and along the lagoon to the northeast from there; a very popular and well maintained reserve with walkers and bicyclists. Relatively very few weeds and rubbish, but let's keep it that way.

  6. The Big seasonal paperbark swamp (BSPS) on the eastern side of the Bridgewater Lifestyle Village, between Len Howard Drive, Oakleigh Drive and Chatswood Drive;

    This reserve is very popular with walkers and bicyclists. It had an enormous number of both fleabane and onion weed plants - certainly by far my greatest challenge. Its area is about 20 hectares (200,000 square metres). As of the end of March 2023 I had dug out over 15,000 onion weeds plants from this reserve.

  7. Novara Beach Reserve
    A beautiful, generally well tended reserve, very popular with walkers and bicyclists, well over a kilometre from my home. Apart from a single dense outbreak it contained only scattered fleabane plants and very few onion weeds when I started on it in February 2023. I added it to my project area because I could have a significant impact with relatively little work.

  8. Osprey Waters Foreshore Reserve
    While this area is about four kilometres from my home and therefore outside of my main work area there were only a few hundred fleabane plants and practically no onion weeds when I started on it. It is a beautiful park, used frequently by walkers, and well worth looking after. By early April 2023 I had removed all the fleabane and onion weed that I could find. I continued, whenever passing through at least to late April.

This section added

Reserve - western junction of Wattleglen Avenue and Silverton Crescent (W/S Reserve)

The reserve, W/S Reserve
The reserve that I'm intending to make a project
Google Earth image

At first I intend to concentrate on the area to the east of the 'basketball court' (lower centre of the image) and south of the scrub. I intend to keep the whole of the area free of fleabane and onion weed.

Pigface I planted at Gleeson Wetlands, Clare, SA
Pigface (Carpobrotus glaucescens?) flowering near the Gleeson Wetlands centre shelter shed, 2018/10/15.

This will provide some year-round greenery and give some very attractive colour when flowering along the sides of the path.

There is a small reserve area at the western junction of Silverton Crescent and Wattleglen Avenue that has been somewhat neglected. I have started planting native pigface (Carpobotus species) and other native groundcovers, shrubs and trees obtained from Men of the Trees, Mandurah branch there and intend to do much more, in consultation with Mandurah Council.

I have also planted pigface and small shrubs along the sides of the public walking/cycling path that leads off to the Southeast of the reserve.

On 2022/05/03 I sprayed all the onion weeds I could see with glyphosate. At that time I counted about 95 pigface plants along the shared path and another 20 in the little reserve.

Seedlings that I have planted in the reserve include:

  • Anigozanthos species (kangaroo paw)
  • Callistemon viminalis (Little John)
  • Carpobrotus species
  • Chorizema cordatum
  • Conostylis acuteata
  • Eremophila bicerrata
  • Eremophila glabra
  • Eucalyptus erythrocorys
  • Eucalyptus gomphocephala (tuart)
  • Eucalyptus macrocarpa (mottlecah)
  • Grevillia preissii
  • Hakea laurina
  • Hakea Maria
  • Hakea trifurata
  • Hardenbergia comptoniana
  • Hemiandra pungens (snakebush)
  • Hibbertia grossulariifolia
  • Kunzea baxteri
  • Melaleuca lateritata
  • Melaleuca nesophila
Most of the above have since died.

Seedlings that I have planted by the path include:

  • Anigozanthos species
  • Beaufortia oestiva
  • Dianella revoluta
  • Goodinia varia
  • Hakea varia
  • Tempeltonia regusa (cocky's tongue, red and yellow)
  • Thrytomene baeckeacea
All the above have been obtained from Men of the Trees, Peel branch. This is by far the best source of native plants that I have found in or near Mandurah, and their prices are ridiculously low. I believe that they have a sale every Sunday morning from 9-11am from late Autumn right through Winter and well into Spring.

Bunnings have plants for sale, but most are not Australian natives, the range of natives they have is small, and their prices are quite high.

Also see the note on my disagreement with Mandurah Council over this project elsewhere on this page.

First vandalism

About ten tree guards were kicked around on 2022/07/07. Only one tree seems to have been damaged. It is pleasing that there had been no vandalism previously. Of course it is to be hoped that this will be a one-off.

Of course there is vandalism in Mandurah, as there is throughout Australia.

In my efforts to revegetate the long neglected land of Crystal Brook's Central Park I had much worse vandalism than this, at one time a vandal pulled out more than a hundred young trees. I went on and I believe that park is still doing well with more than 500 trees and shrubs that a few friends and I planted and looked after.

This section added

Storm water sump on Wattleglen Avenue
Another project area

One of the few unfenced storm water drainage pits in the Mandurah area is on the south side of Wattleglen Avenue close to its western intersection with the Old Coast Road. For this page I've abbreviated its name to SWS (storm water sump).

The sump/pit is surrounded by native bush but the outer parts have been badly invaded by dune onion weed. At the time of writing this section I had sprayed a number of the plants with roundup on two occasions. I became more serious in removing the onion weed in mid March 2023, when I felt I had other areas under some level of control.

It is an area where there is a lot of dumping of rubbish, which I pick up from time to time.

This section added

Dune onion weed (Trachyandra divaricata,)

Onion weed hoed out
onion weeds hoed out
On a part of the path running alongside the Len Howard Conservation Park, 2022/06/13

Extract from Urban Bushland Council WA Inc
Dune onion weed

About this weed
This perennial herb is a native of South Africa and is now widespread on the Swan Coastal Plain especially in coastal heathland in white and grey sand. It is similar to Onion Weed Asphodelus fistulosus in appearance but has flat leaves and the flowering stalks [are] widely branched.

A rhizomatous, perennial herb growing to 0.35 m high. The plant produces tall flowering stalks with small white flowers in spring.

Impact on Bushland
A major weed of coastal dunes and is spreading inland. Fleshy leaves are able to spread over the sand surface and may be up to 1 m long, making older plants competitive for space. Has variable fruit set, affected by the age of plants and weather conditions. Has adaptions for dispersal by wind and water. Wind dislodges and carries crowns of mature inflorescences acting as a tumbleweed, spreading numerous small seeds. Germination is inhibited by light, a response to blowing sand habitats where germination on the dry surface could prove detrimental. Poisonous to mammals.


Council and Parks and Wildlife Service involvement August 2022

Mandurah City Council

I think it was 9th August when a council employee I met at the big seasonal paperbark swamp told me that council would spray the heavy onion weed infestations adjacent to Oakleigh Drive at the northern end of the swamp. By 18th August there was no indication of council weed control so I decided to hoe out those onion weed plants that were starting to flower; plainly it was important to not allow them to set seed.

Parks and Wildlife Service

On 17th August a P&WS employee I met at the Len Howard Conservation Park car park by the lagoon and 'Nature's Eye' shelter told me that they would be spraying weeds in the area on the 18th. I don't think they would find many onion weeds or fleabane because I've got most of them. On the other hand, I will be very interested to see if there is any control of the very heavy infestation of onion weed in the area of LHCP north of my area of operation.

Update 2022/09/14

Someone, presumably the council, have scraped bare a strip of ground adjacent to Oakleigh Drive on the north side of the BSPS. This has at least stopped some onion weed from flowering, but whether it will help in controlling the infestation remains to be seen (it may spread the bulbuls over a larger area).

I have seen no indication that either council or PWS have done any work toward controlling the local onion weed which was well on the way to setting seed.

Mass of bulbul-based false onion weed plants
False onion weed bulbuls
The great majority of these tiny plants with attached bulbuls were within a couple of centimetres of the path. I hadn't seen anywhere near so many massed together in such a small area anywhere else.

By early November most of the onion weeds in the area I was targeting were small plants such as these, with only a very few leaves each. There were very few of the larger clumps, such as in the earlier photos, remaining.

Photo iPhone 11 Pro, standard lens, 2022/09/26

At the time of writing this section I have removed all the fleabane plants I could find in or adjacent to the Len Howard reserve within a kilometre of my house and the small unnamed reserve at the Silverton/Wattleglen junction.

Another bad invasive weed in the area is dune onion weed (Trachyandra divaricata, other common names are false onion weed and strapweed). I started controlling this in the reserve at the western Silverton/Wattleglen junction in May and at that time had done a very little work on this weed elsewhere.

Spraying with glyphosate seemed to be effective, but took a very long time to kill the plants in winter.

By mid June I had started making a serious effort at removing onion weed in the small unnamed park and along the edge of the Len Howard Reserve.

Onion weed control methods

Sometimes the plants could be successfully hand pulled but in most cases only the tops pull off leaving the roots and tuberous base in the ground. The most reliable way of control available to me seemed to be hoeing, so as to remove as much of the plant and its roots as possible. Sometimes the plants would re-root if dug up and left lying on moist ground. Shaking all soil off makes re-rooting less likely and re-rooting doesn't happen when the ground is dry. Where they were numerous I usually heaped up the plants that I had hoed out. Placing dug up onion weeds on a log or something other than the soil also minimises the chance of re-rooting.

I've heard an opinion that digging out dune onion weed is ineffective. I can't imagine that the removal of the plants with the majority of their roots and bulbuls would be ineffective and I note that Urban Bushland Council WA Inc recommends "Manually remove isolated or small infestations prior to flowering. Wipe with 50% Glyphosate solution before flowering. Optimum time for removal – any month."

I have had moderate success spraying onion weed with glyphosate so long as the plants were actively growing at the time.

Progress on onion weed

June 2022; By 2022/06/21 I had been seriously working at removing onion weed in the big seasonal paperbark swamp (BSPS) for a few days (I didn't start counting how many plants I hoed until 2nd July).

While there is a huge amount of onion weed adjacent to or in the LHCP east of the BSPS I have no intention of trying to remove onion weed further from home than the BSPS.

July 2022; By 2022/07/17 I had hoed out over 500 onion weeds in and adjacent to the park at the Wattleglen/Silverton intersection; all I could find to that point.

  • On 2022/07/02 I hoed out about 270 onion weed plants in the northern end of the swamp area and estimated that there were over a thousand left.
  • On 6th July I hoed out another 310 or so, and pulled out about 20 small fleabane plants.
  • On 7th July another 230 onion weeds;
  • 8th 320;
  • 10th 106 (these were at the south end of big swamp, so far as I know they are now all removed from there);
  • 11th 428 (a passer-by said "I think you're fighting a losing battle"; I will enjoy proving him wrong);
  • 12th, 366 removed from the Silverton/Wattleglen (S/W) reserve;
  • 13th, 203 from S/W reserve;
  • 14th, 100 in the morning, N end paperbark swamp, adjacent to Oakleigh Drive;
  • 15th, 112, N end;
  • 16th, 210, N end;
  • 17th, 131, from S/W reserve;
  • 18th, 110 in the morning by the Nature's Eye car park on the edge of the Peel lagoon; within a very few metres of the Len Howard Conservation Park sign. Perhaps the densest patch I’ve seen, I went back later; couldn’t make any meaningful count, many hundreds in a small area. (I spoke to one employee of the Parks and Wildlife Service who I happened to meet there, and to his boss on the telephone at the same time. Both were pleased with what I was doing.)
  • 19th, 152, lagoon car park again, further west. I dug out all that I could find in the car park area and heaped them up;
  • 20th, big swamp 259, N end, hoed and heaped; 144 in SE and NE corners;
  • 21st, 149, N end, about 30 fleabane;
  • 22nd, 137, NE corner, about 15 fleabane;
  • 23rd, 170, N end, a few fleabanes;
  • 24th, 148, NE corner;
  • 25th, 302, NW corner in am. 148 on the path to the Nature's Eye car park in pm; these were scattered plants that I had missed earlier;
  • 26th, 236, NE corner;
  • 29th, am, 242, N end; about 200 in pm adjacent path to car park and right adjacent the information sign in the car park. The latter is the densest patch I've seen anywhere. Whoever put the signs in must have brought gravel loaded with onion weed seed in at the same time;
  • 30th, 510, N end. The most I've taken out in one session;
  • 31st, 146, N end;
  • 1st August, 152, N end;
  • 2nd August - ... Temporary halt to removing onion weed from Council controlled land after being reprimanded for removing the weeds by a council ranger;
  • 9th August, 117 onion weeds removed from the path bordering Len Howard Way and in the car park area near Nature's Eye shelter and 58 scattered plants at the N end of the swamp, inside the outer path;
  • 10th, 550 NE corner of swamp, outside the outer path;
  • 12th, 186 NE corner, plus a lot of previously dug out plants that were re-rooting;
  • 13th, 145, N and S ends;
  • 15th, 78, N and S ends, and rerooting plants;
  • 17th, 20 from car park by lagoon, 150 from W/S reserve;
  • 18th, 142, NW corner, mainly plants that were getting ready to flower;
  • 19th, 220, N end, about half had rerooted;
  • 20th, 170, NW corner, some of them starting to go to seed;
  • 21st, 228, N end;
  • 22nd, 313, NW corner;
  • 23rd, 320, NW corner;
  • 24th, sprayed onion weed around the storm water sump (SWS), Wattleglen Avenue. Glyphosate;
  • 25th, 326, NW corner of swamp. Still overflowing;
  • 8th September, 208, NW corner of the BSPS area, the swamp was till overflowing. The onion weed that I had sprayed at SWS was dead or dying;
  • 15th, 231, N end;
  • 16th, 164, NW corner;
  • 17th, 266, N end;
  • 19th, 250, N end;
  • 20th, 30, adjacent LHCP path toward car park;
  • 21st, 50 adjacent LHCP path toward car park; 151, BSPS N end;
  • 22nd, 69, last of the plants at the northern end of the BSPS against Oakleigh Drive, the worst area with the most weeds. A milestone. Next up the area beside the northern end of Len Howard Drive. The swamp is still overflowing;
  • 23rd, 231, N end Len Howard Drive;
  • 24th, 153, ditto;
  • 25th, 251, ditto;
  • 26th, 231 in the morning, in afternoon 300 scattered, all N end;
  • 27th, Sprayed the remaining massed plants bordering Len Howard Drive. All the onion weed I had intended to control has now been attacked at least once. Now I will follow up with the stragglers.
  • 28th, I didn't remove any more onion weeds but noticed that the BSPS had stopped overflowing into the lagoon.
  • 4th October, 173 removed from adjacent to the path along Glendart court
  • 5th, 324 removed, NE end BSPS, in and adjacent to scraped strip by Oakleigh. All I could find without searching
  • 6th, 197, car park, by shelter sign. The sum of onion weed plants removed is now 12,500
  • 7th, 19 N end
  • 9th, 161, onion weeds beside footpath, Glendart
  • 10th, 52, ditto
  • 12th, 184, reserve behind our house; 75 BSPS, N end, inner path
  • 13th, sprayed dense patches against N end of Len Howard Drive again
  • 17th, 11, BSPS, N end
  • 18th, 44, Glendart and car park. Water level in BSPS is falling quickly. (I found at least 12 kangaroos. They seem to be staying in the scrub more than they were.)
  • 23rd, app. 200, last of massed onion weeds, NW corner of BSPS, adjacent LH Drive
  • 26th, about 200 onion weed in W/S Reserve
  • 3rd November, 62 scattered remainder, NW corner BSPS
  • 4th, 65 in BSPS, mostly NW corner
  • 5th, 102 BSPS, NW corner
  • 8th, app. 200, NW corner of BSPS
  • 10th, 210, NW corner
  • 11th, 110, NW corner
  • 12th, 103, N end

    Late November; emphasis begins to change from onion weed to fleabane

    At about this time much of my time started to be put into fleabane control as much as onion weed control.

    Method of control

    Late in 2022 the method I am continuing to use to control onion weed is digging out and moving the bulbuls to locations where they will be unlikely to take root. I haven't used glyphosate against onion weed except in the storm water sump and the heaviest infestations in the NW corner of the BSPS. My impression is that it is most efficacious when the weed is actively growing.
  • 14th, 105, N end
  • 15th, 111, NW corner
  • 16th, 103, corner of Galbraith and Wattleglen in the SWS reserve
  • 17th, 157, N end BSPS. The great majority of onion weed plants remaining are very small, often with just one leaf. This is very different to the situation a month earlier.
  • 18th, 226, W/S reserve
  • 21st, 85 onion weed in W/S reserve
  • 25th, 82 onion weed N end BSPS
  • 26th, 168 N end BSPS; 120 from beside path on Glendart Court
  • 27th, 332 from the path on Glendart Court, and 215 N end BSPS
  • 28th, 166 Glendart Court
  • 30th, 170 W/S reserve
  • 1st December 158, W/S reserve. 210 BSPS, NW corner. 224 BSPS, N end
  • 3rd, 128 S end of BSPS
  • 4th, 58, junction of Silverton and LHCP; 54 NE corner BSPS
  • 7th, 61, Glendart Court
  • 8th, about 50 NW corner of BSPS
  • 10th, 213 mid NE area BSPS
  • 13th, 104 scattered plants hoed inside outer path N end of BSPS
  • 14th, 108 BSPS, NW corner
  • 15th, 33 BSPS N end, adjacent outer path, 83 W/S reserve, lagoon car park and Glendart Court;
  • 16th, 103 BSPS, adjacent inner path, N end;
  • 19th, about 20 adjacent Glendart Court;
  • 20th, 69 NE corner of BSPS
  • 24th, hoed about 60 scattered plants from N end BSPS.
    The total number of onion weed plants removed to this date was about 18,000
  • 26th, 213, N end BSPS, between paths
  • 27th, 228, BSPS, N end, near inside path
  • 28th, 215, BSPS, NE corner, mostly inside paths. 66, Len Howard Drive and Glendart Court

  • 2023, January 6th, 105 near inside path, N end BSPS
  • 7th, 47 N end BSPS. It is now becoming difficult to find 100 onion weed plants in the northern end of the BSPS in a 'normal' work session! It used to be easy. After more than 100 sessions that has to indicate progress
  • 8th, 40 N end BSPS, also hoed and pulled fb. Also planted acacia saligna and hardenbergia comptoniana seeds
  • 9th, 1 dug out BSPS
  • 10th, 16 dug out of W/S reserve
  • 11th, 1 ow E side BSPS. 4 ow W/S reserve
  • 12th, 7 BSPS; evening 7 BSPS, seeding. 9ow W/S reserve
  • 13th, 15 BSPS, seeding
  • 14th, 25, N end BSPS, seeding
  • 15th, 116, N end BSPS, seeding
  • 20th, 110, N end BSPS over a period of 70 minutes, seeding
  • 22nd, 5, S end BSPS
  • 23rd, 41, SE corner BSPS
  • 25th, 12, N end BSPS
  • 26th, 49, scattered NW corner BSPS
  • 27th, 1, W side BSPS
  • 2nd February, 23 scattered N end BSPS
  • 17th, 9 NE corner BSPS
  • 18th, 34, N end BSPS
  • 25th, one, N end BSPS
  • 26th, one, E side BSPS
  • 2nd March 2023, hoed out about 20 plants in the northern end of the BSPS
  • 4th, 1 hoed out BSPS
  • 6th, 106 hoed out in the WOGL reserve
  • 10th, about 10 hoed out in WOGL reserve. About 20 in BSPS in pm.
  • 11th, dug out about 6 northern end BSPS, about 10 adjacent Dampier Avenue and Dampier Court
  • 12th, dug out about 20 N end BSPS
  • 14th, 254 plants south side of WOGL reserve and on west side of SWS. In pm 18 beside the path, adjacent to LHCP and Glendart Court.
  • 16th, 44 hoed out, N end BSPS
  • 19th, 141 hoed out, WOGL and SWS reserves
  • 22nd, 161 hoed out, SWS
  • 23rd, one hoed out BSPS (that's all I saw)
  • 24th, hoed 163 SWS
  • 25th, hoed 122 SWS
  • 26th, hoed 187 SWS
  • 27th, 118 SWS
  • 28th, hoed 105 SWS
  • 29th, 88, SWS; that was all I could find. In afternoon, 22 from W/S Reserve.

    Onion weed bulbs shooting

    On 2nd April, following 8mm of rain on 26th and 14mm on 31st March I noticed that onion weed bulbs in the SWS reserve that had earlier had their tops scraped off were shooting.

    Differences in recurrence

    March-April 2023. The area around the information shelter near the LHCP car park was heavily infested - very little recurrence. Adjacent the path on Glendart and Dampier was lightly infested - frequent and persistent recurrence.


    On 2023/04/14 I noticed that a very few of the onion weed plants in the BSPS had been grazed. Perhaps by young kangaroos that had not learned to ovoid them?
  • 30th, about 6 from BSPS, N end. Rough sum: 20,800 onion weeds removed to this date.
  • 31st, 9ow BSPS. About 10 dug out on path adjacent LHCP. 65 SWS. 316 WOGL reserve, mainly NE corner.
  • April 1st, 120 WOGL reserve, Western side. About 15 on path adjacent to LHCP and about the same number around BSPS.
  • 2nd, 436 SWS
  • 3rd, 12 SWS. That's all I could find in SWS and WOGL for the present.
  • 4th, 104, BSPS, mainly N end
  • 5th, 68 W/S reserve
  • 9th, about 10 beside path Glendart/Dampier
  • 10th, 113 LHCP car park
  • 11th, 142 BSPS
  • 12th, 339 mostly WOGL reserve, some SWS. Several hundred sprayed around SWS.
  • 13th, 163 W/S reserve
  • 14th, 208 S end BSPS. Pm, 111 N end BSPS
  • 24th, 101 w/s reserve, 221 BSPS
  • 26th, 27 Glendart, 39 mostly big plants I’d previously missed by lagoon in Novara Reserve. 261 BSPS N end
  • 28th, 12, Novara Foreshore Reserve
  • May 1st, 122 W/S reserve
  • 2nd, 8 adjacent path on Glendart Court
  • 3rd, 103 in W/S reserve; 360, BSPS
  • 4th, 275 hoed, N end BSPS. Several hundred plants sprayed with glyphosate at the SWS reserve
  • 5th, 603 hoed out in the WOGL reserve
  • 6th, 205 hoed out, N end BSPS
  • 8th, 235, N end BSPS

    Stage of plants being found

    In the areas I have been working on for months I've noticed that the great majority of plants had only 2-3 leaves. I'm now finding only a very few with more than ten or so leaves.

    However, I've recently dug out many big plants from the WOGL reserve and there are still many in the SWS reserve - both of which are relatively new on my list of target areas.



    I dug out 53 mature plants that I hadn’t noticed until recently from inside the LHCP close to the concrete path on Len Howard Drive. I would have thought that there were no big mature plants left in my main area of operation.
  • 9th, 252, E side BSPS.
  • 10th, 151 W/S reserve; 174 WOGL reserve
  • 15th, at least 500 hoed out adjacent the inside path, N end BSPS. These were in several masses of many tiny plants - I had not previously come across quite as many plants in such small areas.
  • 16th, 308 N end of BSPS
  • 17th, 150 SWS, 47 W/S reserve
  • 19th, 117 bops, all around
  • 20th, 28 LHCP trail
  • 21st, 89 path adjacent LHCP
  • 24th, 53 in LHCP, near concrete path.

Also see the section on progress with the control of fleabane on this page.

Dune onion weed starting to flower
Onion weed budding
Northern end of big swamp, 2022/07/15.
Comment added
As shown in the photo on the right, at this time (mid July 2022) the onion weed was getting ready to flower and set seed. Many plants will set seed; I can't hoe them all out in time to stop that, but there will be over 6000 plants less setting seed than there would have been had I not worked at eradication.

What could be mistaken for dune onion weed (Trachyandra divaricata)?

Young Trachyandra divaricata plants have a distinctive feel, their leaves have a particular type of sandpapery roughness that distinguishes them from plants that might look superficially similar. And the young leaves are round in cross section, more mature leaves are flat and have a smooth feel.
'True' onion weed, Asphodelus fistulosus, is probably more correctly called onion weed than is T. divaricata. It is a major weed in the Flinders Ranges of South Australia. Advanced T. divaricata has fairly flat leaves that are sappy inside (juvenile plants have round leaves), A. Fistulosus has round hollow leaves. Asphodelus fistulosus does not seem to occur in the Erskine area where I've been working.

Young grass tree, Xanthorrhoea, plants (commonly called yaccas in the eastern states) could be mistaken for onion weed. Xanthorrhoea have hard angular leaves rather than the soft strappy dune onion weed leaves and they lack the sandpapery roughness of young onion weed leaves. Xanthorrhoea are native plants and should certainly not be destroyed.

Rushes have round stems that could be mistaken for the leaves of dune onion weed, but they are more rigid and harder; again, unlike young onion weed leaves, rushes have a smooth feel. Dune onion weed leaves are more oval or flat in cross section than round, softer and more fleshy than rush stems. Rushes, at least locally, seem to grow in areas more inclined to water-logging than where onion weed generally grows.

Nut grass (or what I call nut grass, it grows locally and back in SA too) has a thin single stem, very tough and fibrous (could be used to make string?) and a bulb at the base. It can be mistaken for the first single stem of a seedling onion weed but is not at all sappy.

Dune onion weed
Photo iPhone 11 Pro, standard lens, 2022/08/18

Onion weed going to seed

The photo on the right shows dune onion weed plants at the northern end of the BSPS that were going to seed at the time, 2022/08/18.

I had been told by a council employee that council would spray these plants with an appropriate weedicide, but as they were going to seed and had not been sprayed I decided that I needed to hoe them out before they could set seed.

Once they had flowered it would be possible for them to set seed even if they were hoed out.

I didn't manage to get them all out before they went to seed.

This section added

Big seasonal paperbark swamp (BSPS)

The 'Big seasonal paperbark swamp', BSPS
Aerial image of the swamp
This Google Earth image, dated 2018/11/14, shows water in two places in the swamp. Most times of a typical year there is no surface water present. The Bridgewater Lifestyle Village is beyond the first row of houses on the left of the image.

The inner part of the BSPS is the responsibility of the Parks and Wildlife Service, while the outer more open parts, are council responsibility.

This area, of about 20 hectares, which should but doesn't seem to have a formal name, is on the NE side of the Bridgewater Lifestyle Village and adjacent to and north of the Len Howard Conservation Park. It's not clear to me whether this area is included in the Len Howard Conservation Park.

This area, the name of which I have abbreviated to BSPS on this page, had certainly taken up most of my time and effort in weed control in the second half of 2022. It was far more seriously infested with fleabane than I at first realised; and onion weed had a strong hold in parts, particularly the northern end.

In several places there are big gaps between the gum trees in the reserve surrounding this swamp. Bare areas attract weeds, and both fleabane and onion weed had invaded these areas; I have worked at removing these two weed species in this area and elsewhere in the vicinity.

About 2022/06/18 I contacted Mandurah Council asking their opinion on my planting some attractive trees in these areas. I feel it would both discourage weeds and make the area more attractive. By 2022/07/08 I had not received a reply so I contacted them again again asking about planting and informing them again about my efforts to remove fleabane and onion weed. I eventually received a reply stating that the area was not Council's responsibility, it was that of the WA Planning Commission, so I contacted them in early July (by the end of July I had not received a reply). I have been told since that the more outer parts of the swamp area are Council's responsibility, the inner part is the responsibility of the Parks and Wildlife Service.

How hard the numerous kangaroos would be on any trees that I might plant is an open question, but my experience with planting in the Silverton/Wattleglen reserve suggested that gum tree seedlings were not very attractive as kangaroo food.

How the swamp came to be a reserve

On 2022/08/08 I was told by an employee of the City of Mandurah that a condition of the development of the Bridgewater Lifestyle Village was that the swamp area had to be kept in its natural state as a reserve. Both areas were owned by the same people,

Tall fleabane plant
A tall fleabane plant
Around the outside of the BSPS the plants are slashed periodically. Further into the swamp area no slashing is done. This is one of taller of the hundreds of fleabane plants I came across in the reserve area out of sight of the perimeter path. I placed it against my bike for scale.
This section added

Odd comments

About mid July I was hoeing out onion weeds in the big seasonal paperbark swamp adjacent to one of the paved trails, when a man stopped and asked: "Why are you doing that?" as if my purpose was unimaginable to him. Was he unusual or would it be so incomprehensible to many that a person would want to remove weeds from a conservation park?

2022/07/24, another man stopped and said: "I've got to ask, why are you doing that?" I said something like "I'm digging out weeds; they have no place in a public park." Several other possible answers came to mind after I had thought about it for a while:

  • Would you dig a weed out of your garden? Why then not out of a public park?
  • Do you not care about weeds in your public places?
  • I dig weeds out of my garden, why should I care less about weeds in a public park?
  • If I am unwilling to try to improve our public places, why should anyone else?
  • If no one cares for our parks what will become of them?
  • If you have to ask you will probably not understand my answer.
  • This is a beautiful park which the people of Mandurah are very lucky to have. Removing the most conspicuous, unsightly and invasive weeds can only improve it.
Is caring for our shared environment such an uncommon thing to do? My page on contribution covers the point in depth. My notes on self or all and the rights and needs of future generations are also relevant.

Other weeds

There are many species of introduced plants in the areas where I am working. Of course it is quite impossible for me to remove them all. But I hope I can remove the more conspicuous, problematic, unsightly and invasive species.


Several Lantana plants are growing in Len Howard CP. They should be removed, but I have not attacked them as of February 2023.

Evening primrose

Evening Primrose, plants of the genus Oenothera, are well established between the shared use path and Len Howard Drive along much of the western end of Len Howard CP. I have made no attempt to remove them because they have attractive flowers for several months of the year and they do not seem to be invading the conservation park.

This section added

Maltese cockspur, Centaurea melitensis


Mandurah Council

Before I had identified the weed myself I took a specimen to Council headquarters hoping to get it identified. There was no one there who could help me. I was told that there could be someone at the depot but that the depot was not open to the public.

I submitted a report and inquiry to council giving the location of the first patch of cockspur that I found. I hadn't received a reply by 2022/11/10 so I know nothing about Council's policy regarding Maltese cockspur.

There is a bad outbreak of this weed (Centaurea melitensis) - close to the path, not in the adjacent bush - in the Len Howard Conservation Park adjacent to Glendart Court. There are also quite a few plants in the northern end of the BSPS, near Oakleigh Drive.

It feels sticky and leaves an unpleasant bitter substance on the hand.

For more information on this weed see the Florabase WA page.

Control work...

  • November 3rd, pulled cockspur from a four metre section of the path;
  • 4th, about 60 pulled out from adjacent the path on Glendart Court and others pulled out of BSPS, north end;
  • About 20 plants pulled/dug out NW corner of BSPS;
Later I realised that this weed is quite widespread adjacent to paths through the Erskine area. I've given it a lower priority than Onion weed and fleabane.

This section added

Devil's apple, Solanum linnaeanum

Solanum linnaeanum
I've come across a half dozen or so of these plants scattered around in the northern part of the BSPS.

It is a poisonous native of parts of Southern Africa and considered to be an invasive species in Australia and a number of other places. It is also very prickly, a nasty plant all around!

Common names include devil's apple and apple of Sodom. See Wikipedia.

Photo iPhone 11 Pro, 4.25mm (standard) lens, 2022/12/21

This section added

Caltrop, Tribulus terrestris
Also known as puncturevine

Caltrop is a well established weed in South Australia where I lived before moving to Mandurah. After almost a year in Mandurah the outbreak photographed here is the first I've seen in the area.

Caltrop thoroughly deserves the alternative common name of puncturevine because it is deadly on bicycle tires (also on dog's feet and children's feet).

The image on the right (click on it to see it in higher definition) shows two mature caltrop plants. The photo below shows a pair of the spiked seeds in close-up. It has a small yellow flower with five petals.

I hoed out more than twenty plants in the strip between the road and the concrete shared-use path in front of the vacant lot at 70 Silverton Crescent in Erskine on 11th January 2023. While I removed all I saw you can be sure that seeds would have been left behind. To get to the stage of this infestation would have taken several years.

On the right is a close-up of a part of one of the plants with two of the viciously spiked seeds left of centre.

I'd urge everyone to look out for this plant and remove it when they see it. People near 70 Silverton Crescent, where these plants were found, would do well to be especially vigilant.

The area around Silverton Crescent, Erskine is very popular for cycling. Cyclists would do well to also keep an eye out for caltrop and remove any plants they see.

Caltrop is an annual plant introduced to Australia from southern Eurasia and Africa. It germinates following any summer rain and can grow in soil so dry that little else grows.

Caltrop is a vicious weed that can be controlled with persistence and not a lot of effort.

I wrote a letter on this to the Coastal Times and Mandurah Mail. It was published by the Times in their 2023/01/18 edition, although without the photos and the street number.

Work on caltrop

Apart from the outbreak mentioned above:
  • I had pulled out some caltrop plants on the path adjacent to Len Howard CP;
  • March 2023 On 2023/03/06 I pulled out and removed about 30 plants from the edge of the road adjacent to the WOGL reserve
  • On March 14th I hoed out a half dozen plants, some of them very big, on roadside adjacent the SWS
  • March 31st, about 10 big plants WOGL reserve, North corner
  • April 1st, about 15, WOGL reserve, North corner
  • 4th, about 20 pulled out in front of a vacant block near the eastern end of Silverton Crescent.
  • 12th, probably in excess of a thousand seedlings, and a few larger, sprayed on roadside adjacent SWS

This section added

Mandurah Council

Fleabane colonising bared ground
Photo taken 2022/12/12. See text on the left.

The fleabane was still there in mid February, but much taller.

Any council has a difficult job to do. There are always people who want more done by their council, but who wants to pay higher rates for more services? On the whole I think Mandurah Council does quite well.

The ordinary people could do far more for their communities, but, in Australia at least, in my experience, the great majority don't feel any obligation to do work they might see as council's responsibility. Similarly, most people don't want to do anything for parks that might come under the jurisdiction of state or federal government.

An example of Council's difficult balancing act

This section added
The photo on the right shows an area where somebody, presumably Council, had bared the ground by removing the natural rushes and other native plants beside the path, probably because there are snakes in the area. Most of the plants on the left of the image are fleabane that has taken advantage of the bare ground and colonised it, as might have been anticipated.

Ironically there was a sign less than a 100m away saying that there had been damage to native plants in the area and that a $1,000 fine applied to anyone damaging native vegetation. Will Council fine themselves?

Or have I done Council an injustice, and was the ground bared by some individual who was intending to do good without realising the consequences of his actions?

I informed council and asked whether they, or someone else, had done the clearing. Someone came out to look at this infestation about 23rd. I went back on 30th. It seems that nothing had been done. They didn't tell me whether the clearing had been done by council.

Posts to stop vehicle access to Big Seasonal Paperbark Swamp. Not a lot of use when there is an obvious entry point; see below.
Posts on boundary of swamp
I estimated that there must be about a thousand posts like these around the BSPS. They are about 1.5m apart and the perimeter that is adjacent to public roads is about 1.6km long.
Ground plowed up by yobbos
Yobbo damage
With all those posts to stop vehicular access you'd have to wonder how the yobbos got in.
Easy vehicle access here
Vehicle access to park
Why is this one place left open for yobbos to get access to the park? This one gap makes the thousand posts blocking access elsewhere useless.

The three photos above were taken 2022/11/26. Council were informed that day. There had been no action to fix the situation by the end of 2022, nor had I had any response from Council.

Reprimanded for removing weeds

On 2022/08/01 I was very surprised to be reprimanded for hoeing out onion weeds by a ranger employed of the City of Mandurah. After some conversation I asked her "Does council like having weeds in their parks?" She replied "I didn't say that". Among other foolish things she said to me was: "Digging out anything from a national park, whether it’s a weed or not, is damaging the park.” How bizarre!

While she demanded my name she refused to give her full name. I wonder what sort of education the City of Mandurah demand of its rangers, because she didn't know what onion weed was, in spite of it being a very common and invasive weed in some Mandurah parks. She also accused me of digging out trees, a completely baseless accusation.

Council approve my work removing weeds

On 2022/08/08 I met two council employees at the Big Seasonal Paperbark Swamp (BSPS). They told me that it was quite OK for me to go on with what I had been doing, contrary to what the ranger had said.

P&WS appreciative of my efforts

Unlike the Mandurah City Ranger's reprimanding me for removing onion weed (above), as mentioned in the section on progress on onion weed (18th July), the Parks and Wildlife Service people I spoke to were very happy to have me removing onion weed and fleabane from the Len Howard Conservation Park.

This section added

Glyphosate; a note on toxicity

I added this section to this page on 2022/12/04 after a person alleged to me that glyphosate is a terrible toxic substance. I don't know where she got her information from, but she was quite wrong.

Glyphosate toxicity; information from authoritative sources:

USA Environmental Protection Agency:

  • "No risks of concern to human health from current uses of glyphosate;
  • No indication that children are more sensitive to glyphosate;
  • No evidence that glyphosate causes cancer in humans;
  • No indication that glyphosate is an endocrine disruptor."
Australian Pesticides and Veterinary Medicines Authority (APVMA); “The current assessment by the APVMA is that products containing glyphosate are safe to use according to the label instructions.”

National Library of Medicine, PubMed Central. Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC (International Agency for Research on Cancer).

Elsevier Science Direct; Exposure risk and environmental impacts of glyphosate: Highlights on the toxicity of herbicide co-formulants. It seems that the authors consider the adjuvants in the various formulations are of just as much, or more, concern than the glyphosate itself.

This section added

Is fleabane edible?

I have never seen any evidence of kangaroos having browsed fleabane plants in the Erskine area. So I was surprised to notice that in Caversham wildlife park walk-through kangaroo enclosure the only fleabane plants were where the kangaroos couldn't get to them. This strongly suggested that the kangaroos there ate fleabane when they could get access to it.

I couldn't find anything definite on the Web other than some references to at least some fleabane species being mildly toxic to some animals.

This section added

Letter to Mandurah Mail

The following letter was sent to the Mandurah Mail newspaper 2022/07/16 and published the following week.
“Some people will have noticed an old man (me) digging out onion weeds or pulling out fleabane from parks and paths around Erskine. And they might wonder why he does it.

I’m new to Mandurah, only lived here since February. Back in SA I used to spend a fair bit of my time looking after some parks, planting trees and picking up roadside rubbish. Strange pastimes you may think.

But a bloke needs something to do, and games like bowls and golf have always seemed to me pointless. Why not use your time and energy doing something that will improve your local environment? My web page https://comagecontra.net/Australia/Fleabane.html will give you more information.”

This section added


I have aimed at:
  • Working in important areas - areas of high conservation value;
  • Working within a reasonable distance of my home;
  • Removing the most invasive weeds;
  • Removing the most unsightly weeds;
  • Removing weed species that I am likely to be able to locally eradicate;
  • Preferentially removing weeds where they are in manageable numbers, cleaning up the lighter infestations first;
  • Giving higher priority to areas most frequented by walkers.
I have weeded in Osprey Waters Foreshore and Novara Foreshore Reserves because, while they are a relatively long way from my home, the low numbers of weeds were easy to control.

I have not weeded in the part of Len Howard Reserve east of the BSPS because it is a considerable distance from my home and there is a high level of weed infestation. I have not weeded on the north side of the Old Coast Road because of the heavy traffic and difficulty in crossing the road.

This section added


Most of us like to keep our garden (if we have one) in front of our house (if we have one) looking neat and tidy. But it seems that for most the effort stops there; beyond our front boundary the environment and the aesthetics of the landscape is "someone else's concern, not mine".


Enjoyment of one or all?

You can enjoy your own garden, and passers-by can get some enjoyment from your front garden, but anyone and everyone can get some pleasure from any work you do to improve a public park or garden. So the same amount of work in a public space will lead to more enjoyment than if it was spent in a private garden.

Also see Self or All on another page on this site.

Why should this be so? Don't we all have an obligation to contribute to the communities in which we live? Shouldn't we all make an effort to make our local community and the world just a little bit better place, within our capabilities? Another thing that we could all do to improve our shared environment is picking up rubbish left by careless others.

As a retiree, living on my investments and superannuation, I feel that I have a responsibility to make a personal contribution to the community in which I live. I have written more about this sort of thing in my About Me page. Apart from local work such as discussed on this page I intend to devote the remainder of my life to trying to get action on climate change, especially in Australia, since my nation has such a shameful record on the matter.

I have written short pieces on whatever happened to civic pride? and community spirit on other pages.

Related pages

Related pages on external sites...

Len Howard Conservation Park Trail, by AllTrails

Department of Primary Industries and Regional Development page on fleabane

Urban Bushland Council WA Inc. page on onion weed

Urban Bushland Council WA Inc. page on smooth fleabane

Florabase page on broadleaf or Guernsey fleabane

Related pages on this site...

Bowman Park, Crystal Brook, SA

Cleanup; my efforts to clean up public places

Climate change, the world's great threat and challenge

Climate Walk; a million-step walk to try to get serious action on climate change.

Contibuting to our communities
  Blood donation

Crystal Brook's Central Park, SA

Destruction of roadside vegetation by a body that should be protecting it

Gleeson Wetlands, Clare

Selfishness or altruism?

The remainder of my life

Why I support the local wind farm

Names and abbreviations I've used

Big seasonal paperbark swamp, BSPS
The large reserve area west of Bridgewater Lifestyle Village and south of Oakleigh Drive. See Google Earth image.

Len Howard Conservation Park, LHCP
See the Google Earth image.

Car park on the lagoon in Len Howard Conservation Park
The car parking area near the western end of the Len Howard Conservation Park, Left of centre at the bottom of the Google Earth image.

Reserve at the western junction of Wattleglen and Silverton roads, W/S Reserve.
Also see Google Earth image.

Storm water sump; SWS
The reserve that includes a large pit for storm water runoff toward the western end of Wattleglen Avenue.

WOGL Reserve
The small unnamed reserve between Wattleglen Avenue, Old Coast Road, Galbraith Loop and Lloyd Crescent


On this page...

Abbreviations and names I've used
At the start, Late February 2022
Backward step?
Big seasonal paperbark swamp
Caltrop, Tribulus terrestris, also known as puncturevine
  Work on caltrop
Council and Parks and Wildlife Service involvement August 2022
Dune onion weed
  Onion weed control methods
  Onion weed going to seed
  Onion weed progress
  What could be mistaken for dune onion weed?
Is fleabane edible?
Enjoyment of one or all?
Fleabane control methods
  A fleabane outbreak in the BSPS; one of many
  Fleabane progress
  Fleabane in Novara Beach Reserve
    A note on fleabane adjacent Novara Beach Reserve path
Fleabane in Marlee Reserve
First vandalism
Glyphosate; a note on toxicity
Google Earth images:
  Big seasonal paperbark swamp, BSPS;
  Car Park in Len Howard Conservation Park;
  Len Howard Conservation Park, LHCP;
  Reserve at the western junction of Silverton and Wattleglen, W/S Reserve
Government action?
Kings Park fleabane
Len Howard Conservation Park
Letter to Mandurah Mail
Localised fleabane outbreak
Mandurah Council
Maltese cockspur
Names and abbreviations I've used
Novara Beach Reserve
Novara Foreshore Reserve
Odd comments
Onion weed control methods
Onion weed progress
Osprey Waters Foreshore Reserve
Other weeds
  Centaurea melitensis, Maltese cockspur
  Oenothera species, evening primrose
  Solanum linnaeanum, devil's apple
  Trachyandra divaricata, dune onion weed
  Tribulus terrestris, caltrop
P&WS appreciative of my efforts
Parks and Wildlife Service and Council involvement August 2022
My primary (fleabane removal) project
Project areas
Related pages
Reprimanded for removing weeds
Solanum linnaeanum
Storm water sump on Wattleglen Avenue
Swamp, how it came to be a reserve
Tribulus terrestris, caltrop
Wattleglen Avenue and Silverton Crescent reserve (W/S Reserve)
Wattleglen Avenue storm water sump
WOGL Reserve between Wattleglen Avenue, Old Coast Road, Galbraith Loop and Lloyd Crescent
What could be mistaken for dune onion weed?