Sunday 29 June 2014

Second thoughts

Regular readers will be aware of the problems I have been having with compost contaminated with weedkiller of some sort. My initial diagnosis was that the cause of this was aminopyralid weedkiller in the composted stable manure I had bought earlier in the year, because the plants most seriously affected are the ones in containers filled with the said compost. This includes all the tomato plants, all the potatoes and all the chillis. Also affected are the beans, planted in a raised bed to which more of the suspect manure was added, and a few others.

Chilli plant affected by the weedkiller - note the puckered leaves

This week I have had a talk with a representative from the company from whom I bought the suspect compost. He was adamant that the manure that goes into their compost is taken from the most reliable sources - such as the stables of the Household Cavalry and the Mounted Section of the Metropolitan Police, who are most unlikely to contravene the regulations that govern these harmful substances. Furthermore, their products are supplied to some very high-profile customers, such as the RHS gardens at Wisley. We discussed the way my plants are raised, and I told him that my seeds were sown in small pots of multi-purpose compost prior to transplanting into the big containers in which they are grown to maturity. At this point it dawned on both of us that there was a possibility that the problem was introduced earlier than I had previously imagined - that is to say, in the multi-purpose compost.

According to the person with whom I was speaking, at least 50% of the material used for all the Big Name multi-purpose composts comes from recycled domestic garden waste, collected by the local Councils. This material could easily contain lawn clippings contaminated with weedkiller. It is not supposed to, because instructions for the use of such products tell the user not to put it in the green waste - but then it only needs one illiterate or negligent person to upset the whole scheme! Looking at the website of Dow AgroSciences (the manufacturers of the products in question) I see that it would take only one drop of this stuff in an amount of water equivalent to an Olympic swimming-pool to cause damage to garden plants. Frightening, isn't it? Why are such products licensed for use? They should never be allowed. Domestic gardeners are not even allowed to use Jeyes Fluid any more, yet Big Business is allowed to sell these dreadfully toxic substances. Why?

I have had a really good look around my garden, and I have concluded that it is in all probability the multi-purpose compost that has caused me all the problems, not the composted stable manure, since lots of plants are affected, many of which have not been near the stable manure. the compost I have used recently is called "Westland Multi-purpose Compost with added John Innes", coincidentally sold by the same place, although I bought mine from my local Garden Centre (part of the Diamond Group). I shall be thinking VERY carefully before I buy any more commercial compost of any sort.

Endive seedling showing weedkiller damage symptoms

Radicchio seedling showing weedkiller damage symptoms

The outcome of my discussions with the compost supplier is that they have agreed to refund the price of my purchase. In the circumstances (in the absence of any concrete proof that their product is at fault) I suppose this is fair, but it hardly compensates me for the loss of a substantial proportion of my Summer's crops - especially my beloved tomatoes! This is particularly galling since most of them were very special ones, from seeds supplied to me by a blogging friend in Belgium... Look at this aberration, surely a symptom of the problem described:-

This tomato seems to have produced a "viewing window" so that you can watch the seeds develop!

In future, I will be making strenuous efforts to maximise the amount of home-grown compost I produce, and to minimise my use of commercially-produced products.


  1. What a shame!

  2. They really need to ban weedkillers like these. They do so much damage and persist in the soil for so long.

  3. Considering the amount of rubbish to be found in bought bags of potting compost I'm not surprised at the outcome of the deformities of your crops. It is heartbreaking after all the effort you put in and I do sympathise with the problems you have been having. I have given up on cheap compost now and buy better quality stuff but try to use less mixing my own compost in with it.

  4. Thank you very much for this post. My pepper plants look exactly like yours and I couldn't understand why. They started out completely normally. Then I repotted them for the first time and they developed crippled leaves. After a while that problem got better and I had normal leaves again. I repotted them as they got bigger and only days after repotting the same problem happened again.

    I could not understand that, but now, after reading your post, it makes perfect sense. Also my snow peas, which grow in a container, were malformed and in general nothing grew well in that one container. Just as you describe, only plants in pots are affected in my garden, while the plants growing in my own compost grow normally.

    Thank you for providing this explanation.

  5. Goodness, I've never seen a tomato develop like that before. As you know, I've had problems with compost myself this year, but luckily, it hasn't affected my plants quite as badly as yours. Most gardeners rely on bought in compost so what are we to do if we don't produce enough of our own? They've got us over a barrel really, we're always going to need to buy some so it's just a case of pot luck whether it's contaminated or not.

  6. Its a real shame about some of your plants and the way they seem to have been affected. I hate to think of the contamination in most types of products we buy and use, and the chemicals that seem to seep into most things. Think its a real societal problem.

  7. Thanks for your diligent detective work on this subject Mark just goes to show we should always be on the alert with what we use in our gardens and veg plots

  8. I second David's remarks. Your tenacity in tracking hits down and sharing with us is appreciated.

  9. I do worry about the use of household green waste as there is no way you can be sure what goes into it. It's not easy to dispose of anything diseased or lawn clippings in any other way than through the green bin so it is the disposal method most people will use.

    It's strange isn't it that we can't buy anything to combat club-root any more as there is no product licensed for domestic use but we can buy a lawn weedkiller that can create persistent contamination.

    Proving aminopyralid or clopyralid residue is present is difficult. It may not consistently affect a product as it will depend on the mix and the raw materials used so a supplier could supply lots of other people with no problem. Also when there is a problem many people will put it down to weather or some other cultural problem or blame themselves for not growing correctly, A stable may use a contract sprayer who doesn't pass on information.

    I know of someone else affected this year who went back to the farmer who supplied him to have confirmed that Forefront weedkiller had been used but the farmer seemed unaware that this could cause a problem. Even with al the professed safeguards human error sneaks in to the equation.

    As for making all your own compost - we'd never manage it.

  10. This looks lie the results of 2-4-d lingering in the lawn clippings before they were composted.

  11. Interesting, I always buy bags of compost and am just noticing differences in them. I have had some similar effects on plants so perhaps some of mine were contaminated with weedkiller too.

    I am trialling some different types of peat free composts this year. So far they seem to be OK, but the seedlings are still new. I'm starting with New Horizon and Dalefoot. Dalefoot feels lovely but is too expensive to be practical. New Horizon is nice and chunky but I'm guessing will dry out quickly.


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