On Wednesday 20th April officers from the Peel Harvey Biosecurity Group (PHBG), Jonelle Cleland and Teele Hooper-Worrell, helped a local landowner pull out some cotton bush plants. It is important that landowners know the correct way to remove and dispose of cotton bush. Jonelle Cleland, Executive Officer from the PHBG noted that ‘After removing the green seed pods and placing them straight in a bin bag we were able to pull out the mature plants easily from the soil’. Cotton bush is a declared weed and you are not allowed to simply throw the waste in the bin or put it out on your verge for green waste pickup. You must dispose of the seeds effectively, otherwise they are still viable and can spread to another area.
A great way to prevent the spread of the weed is to use solarisation to kill off the active seeds, with the added benefit of composting some lovely soil for your paddocks or garden beds. Solarisation uses the heat of the sun’s rays to literally cook plants, weed seeds, nematodes, insects, and soil pathogens (the “bad guy” fungi, and bacteria that bring diseases to plants) which occur in the top layer of your soil. It also makes nutrients more available to plants later grown in solarised soil.
Below are some steps for successfully solarising cotton bush plants and seeds you have pulled up on your property.
How to remove and dispose of cotton bush.
How to remove cotton bush
Step 1- If the weed has active pods growing carefully remove and place straight into a bin bag to reduce the spread of the wind borne seeds.
Step 2- pull up the mature plants and stack in an out the way area, on top of an existing compost pile is suitable.
How to dispose of cotton bush
Step 3 – Place plastic bags of seeds in the sun and leave for a few weeks. After the seeds have been cooked the bags can be placed into the bin.
Step 4- Source some thick clear plastic and spread over your mature plants/ and or seeds and weigh down with rocks or bricks. As an alternative you can use black pond liner but it won’t be as quick. Be careful of snakes that may find refuge underneath the plastic.
Solarisation will occur more quickly in summer, in summer you can use the soil after 5 weeks while in winter you may want to leave the plastic on until the weather starts to warm up.