Herbicide damage

Broad-leaf weed killers that contain the pyridine herbicides have caused widespread damage to many gardens in New Zealand, the UK and the US in recent years, and these herbicides are now being sold in Australia.
Pyridine herbicides include aminopyralid, clopyralid, fluroxypyr, picloram, and triclopyr. They are only effective on broad-leaf plants, but the chemicals remain active in mulch cut from sprayed pastures and in manure from animals that have grazed on sprayed pastures until the chemicals are broken down by soil microbes. Of particular concern to home gardeners and councils that recycle waste into compost for agricultural and domestic use are the products containing aminopyralid, clopyralid and picloram because they are quite persistent in compost (particularly anaerobic compost), and residue from these herbicides can damage crops for up to 24 months.

Is it just me, or do other people think it is crazy that there is widespread concern about the future of food production in Australia, and all levels of government are advising us to recycle and store carbon, yet the Australian Pesticide and Veterinary Medicines Authority (APVMA) continues to register more and more of these herbicides that damage food crops, and little if anything is being done to warn the public of the risk in using mulches, composts or manures contaminated by these herbicides.
Although there are only two pyridine herbicides containing aminopyralid (Hotshot and Grazon Extra), the APVMA has registered 59 herbicides containing clopyralid, 54 containing picloram, 27 containing fluroxypyr, and 77 containing triclorpyr, and there are several more of these herbicides awaiting approval – an impossible list to remember when purchasing mulches, manures or compost.

The problem with Australian regulating authorities is that they regard the person who sprays the herbicide as the ‘end user of the product’ and any warnings are limited to product labels without any regard for the unsuspecting gardeners who, in good faith, purchase mulch, compost or manures contaminated with the herbicide, and who may not recognise the cause of the damage to their crops because they have not personally used any herbicides.

I am very grateful to Jo T. who has sent me a link to photos of damage to vegetable plants caused by aminopyralid. These may help readers identify this herbicide problem in their gardens.

If you are unfortunate enough to have garden beds affected by these herbicides, click here for treatment information.
See also Herbicide warning.

Further Information:
You can find Australian product names of these herbicides by going to APVMA’s Public Chemical Registration Information System page. Select herbicide and then type aminopyralid, clopyralid or picloram in the active constituent panel.
The NSW Government has been aware of the problems with these herbicides in Australia since 2005:http://www.environment.nsw.gov.au/resources/warr/SPD_ORG_ReduceRiskHerbCompost_FS.pdf
Jo has also provided a link to UK information about aminopyralid problems.

3 thoughts on “Herbicide damage

  1. Thank you for this blog. Judging by the photos in the link, that is the problem we have in a load of gardening dirt bought at a landscape supplier in Brisbane. I was not even aware of this possibility; it’s a shock and a shame. This garden was a joint venture with my two year old. – Alice

    What a terrible disappointment Alice. This post was written in 2010 and you can read more recent information in this post: Manure and mulch warning update
    I hope you reported the problem to the supplier because manures or mulch treated with these herbicides are not to be used on gardens, and also to the APVMA. In the meantime, can you get your child’s garden started in pots while you follow the steps indicated to get the soil microorganisms working as fast as possible. – Lyn

  2. It never ceases to amaze me how ignorant people can be. I was listening to a conversation the other day while picking up kids from school between a couple of mum’s – one mum sprouting on about the joys of glyphosate mixed with a cup of kerosene. Both of these mum’s have young children that would be out playing in the garden. I can’t believe people want to spray poisons around their yards where children and pets, let alone yourself must come in contact with this stuff. The bloke who mows my father’s lawn told him it was safe enough to drink! I promptly printed of a MSDS and showed it to my dad.
    I really worry about the way we have become reliant of such chemicals and so lazy that we can’t pull weeds out, smoother them with mulch, or cut them out with a line trimmer – especially in a home situation. If you are using these chemicals in an industrial situation you are supposed to have a chemcert certificate to buy or apply chemicals (not that I have ever been asked for it) but anybody can nip down to the local shops and pick enough to destroy their entire ecosystem. We really need to re-think our reliance on these chemicals and what they are doing to our food systems.

    So true Debra, but trying to get the APVMA or Government to listen is like talking to a brick wall. We probably need to organise a petition or some sort of group action. – Lyn

  3. There is a newly introduced certified organic herbicide on the Australian market by Go Natural (www.gonaturalgardening.com.au). This herbicide is made from Pine Oil and rain water, no other ingredients. It is ready to use and price competitive, retails for $14.99 for a 500ml bottle. I have tried it and am very happy with the results.

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