Buyer beware

Back in June 2008 all was not well on our allotment site. 

It started with a report of strange curly, fern like leaves on the tomato plants in the polytunnel of one plot holder.

Tomatoes- fern like growth

At first we didn't realise the significance and then gradually potatoes on several plots began to display similar leaf problems.

Potatoes - fern like growth and leathery cupped leaves

The top leaves resembled fern fronds and lower leaves were leathery  and curled up like a spoon.

We soon realised that all of the effected plots had bought manure from the same source and so suspected that the manure was the problem. I then started scouring the Internet for any information or confirmation of our suspicions. I eventually came across a post from the RHS asking for anyone who thought they had problems caused by manure to get in touch. I did and our case confirmed the RHS suspicions as we were the first to contact them having several 'gardens' displaying the same symptoms after obtaining manure from the same source. We had extensive 'conversations' with the RHS and it appeared that our problem was linked to use of a hormonal weedkiller containing aminopyralid - ForeFront. This was being used contrary to the way stipulated meaning that the contamination was getting into manure supplied to us gardeners.

Runner beans -Leaves thick and leathery with pronounced veins which tend to run parallel. Leaves cupped like a spoon.

I decided to find out as much about this as I could and had long email and telephone conversations with officers from the CRD - Chemicals Regulation Directorate and the manufacturers DOW, which included a visit from one of their consultants. I also decided that I needed to pass on as much information as I could and so published everything that I had found out on my website here.

Peas - cupped leaves

Along with others I also campaign to get as much publicity as possible through email, forums, newspaper/magazins articles, TV appearances and local radio interviews. Also many people who had suffered the same problem contacted me and I recorded their experiences here.

Runner beans - stunted growth, new growth fern-like, leathery cupped leaves,with prominent parallel veining

From these emails it became clear that it wasn't just manure that was causing problems but that there seemed to be some contamination of commercial composts. To cut a long story shorter my Internet research revealed that a lawn weedkiller - Verdone - available to amateur gardeners contains an active ingredient - clopyralid - which is also hormonal and behaves in the same way. Having used this weedkiller on lawns gardeners are told not to compost the clippings and so as a result they end up in green waste bins and many composts use green waste as an ingredient. 

Broad beans - cupped leaves

The way in which any chemical residue is released is quite complex and the processing carried out by compost makers will not remove it and so it will remain in the compost material undetected. If you want to know more about this go to this page and read the section - Can testing help? When the gardener uses the compost the residue is released gradually and at first all is well. Over time plants start to show signs of contamination and struggle. The level of contamination will vary and some plant will grow through it  but these plants must not be composted. I have scattered photos of the classic signs of hormonal weedkiller damage throughout this post and all can be viewed larger by clicking in the image.

Broad beans - cupped folded leaves , few flowers setting

Beans, peas, tomatoes, potatoes, raspberries, dahlias and roses are among the plants most badly affected by contamination but this list isn't conclusive.

Tomatoes

So why am I mentioning this again now? Well despite all the knowledge about this problem it is still affecting gardeners. If you follow Mark at Mark's Veg Plot you will know that he is still wrestling with the effects of using suspected contaminated compost a couple of years ago.

Then last week I received this email which I reproduce with Ann's permission:

Hi Sue,

I can imagine that by now you must have had more than enough of this issue, but as you were so amazingly helpful in 2011, I thought I'd at least let you know that we've been hit by this horrible poison yet again.

This time it has affected our community growing project: Edible Mach. We are part of the greater Incredible Edible Network and as part of our work this year we have created a Show Allotment in the heart of our town; Machynlleth. All went well until a couple of weeks ago when I spotted a familiar distortion of the growth on the broad beans. My heart sank as I realised it was Aminopyralid again. We bought in 8 tonnes of peat free compost and that is what we traced it back to. This compost gets made in part by what is put in the green waste stream, so it is probably Clopyralid, rather than it's evil big sister; Amino.

I'm hoping it will not get too bad, but worse case scenario would be that all our growing sites will be affected (12 of them, all over the town), as all had a top dressing of this compost. We are now gearing up for the fight with the supplier, who we paid £800 for this compost and who is trying hard to deny any responsibility. Would you be able to tell me if Trading Standards are any use in this kind of scenario?

We're hoping to give a lot of publicity to the issue once again, as we will have an official opening of the allotment with the press there and hopefully Incredible Edible will help too. There have been other incidences around the area as well this spring and for our market garden, this is the third time we've been hit in 6 years, despite all the precautions we now take, so clearly this problem is not going away. Maybe we need another pin in the map?

All the best and your allotment is looking amazing!


Ann Owen

It's bad enough when it affects us home growers but for Ann this is the second time her business has been hit.

It is at this time of year when cases of contamination are spotted and if it affects a gardener in isolation it is easy to blame something else for the aberrations. This year you could easily blame the weather. If you do suspect that you have used contaminated materials, make a fuss and go back to your supplier.

If you want to learn more my section on manure contamination is on my website here  but be warned some of it is just transcripts of conversations and not for the faint-hearted. There are plenty more photos though too.

Footnote:
I have since found out that clopyralid is an ingredient in Lawn Clear, Weedol Lawn Weedkiller and Green Up Lawn Feed and Weed. (There may be more).

Also there are other hormone type weedlillers including 2,4-D, mecoprop-P, MCPA and dicamba which may have the same problem. Make sure that you read lables on weedkillers carefully.

Copyright: Original post from Our Plot at Green Lane Allotments http://glallotments.blogspot.co.uk/ author S Garrett