
Cape Weed. Juvenile rosette formation prior to flowering.
Cape Weed is a highly successful weed after a bushfire event – it returned in overwhelming levels with the rosettes that formed in the first recovery year being a metre across. It is comonly found in grazed paddocks particularly those which have had horses. Pigs are quite fond of it a local pig farmer has no Cape Weed on her block yet all her neighbours with horses have large amounts of this weed.
We are working with our neighbours (uphill) who have quite a bit of Cape Weed – Arctotheca calendula. This year we have noticed a few Cape Weed rosettes starting to grow on our bush block since May and at this stage have been able to hand pull these out. Hand pulling is the best technique amongst all the indigenous plants on our block and manageable. But we know that as a long term plan unless we can manage the weed levels next door Cape Weed will just re-infest our block paticularly as we are down hill as seeds can then travel by wind, water or by insects or other animals onto our block.
My neighbours have actually tried chemicals and mowing techniques but this is one tough weed that has a winning strategy for most eradication techniques. Mowing tends to cause the weed to flower really low to the ground below the mowers blade allowing it to flower and seed as usual. Chemical control can help to reduce the amount of flowering (and seeding) of Cape Weed, but unless other controls are used it is a struggle to completely eradicate it this way. The area infected by Cape Weed needs to be replaced by another species or other ground cover to really reduce the ability of this weed to take hold through competition – as Cape Weed loves bare ground.

Cape Weed reduction using carpets to cover the weed.
Some techniques used in permaculture have helped us, such as cover weeds with weeds and let them compete against each other. From this technique we have been most succesful using a covering technique. Simply covering weedy areas with old carpets we have found free on the hard waste or simply covering with black plastic, tin or anything else that will block out light (and water as best as possible). The earlier the covering rotation is started the better, from about May onwards. Once they flower around August it is all to late to have really successful reduction as they will seed.
No plants can survive without light, but we have found that our indigenous grassy plants such as Weeping Grass, Wallaby Grass, Flax Lillies (Dianella’s), Saw Sedge (Gahnia’s) and Mat Rushes (Lomandra) actually have the ability to bounce back if not covered for too long. Covering for about 3 weeks is enough to completely eliminate Cape Weed, but the indigenous plants although they may have turned yellow have tough roots and mostly have the ability to recover from this treatment.
Once the Cape Weed has died off it is important to replace the now bare soil as otherwise Cape Weed will just return. For instance our neighours would like to retain a grassy paddock for grazing but don’t want more weedy pasture grasses which are infesting their natural bush so have seeded bare areas (where Cape Weed was removed) with indigenous wallaby grasses and Weeping Grass. The seed collected from these indigenous grasses on their block whilst they seeded over the late summer months. They can mow and maintain these indigeous grasses as a lawn or for pasture for stock or fowl.
We also know that we won’t eliminate Cape Weed this year, but we now have a plan that is working and each year we hope to reduce the amount of infested area. We also know that we can’t give up as this will just give the Cape Weed the chance it needs to return to a thriving state.