Wednesday, 15 June 2016

That old weedkiller problem again

I'm sure that many regular readers will remember me writing about problems I had during 2014 and 2015 with compost contaminated with weedkiller. Last year the problem was less bad than the previous year, and I thought that perhaps I'd seen the last if it. Unfortunately not.




I am about 99.9% sure that the problems I encountered were caused by weedkiller contamination in multi-purpose compost produced by the firm Westland. For this reason I resolved to stop using their products. I was also at one stage suspicious of the composted stable manure I used to use, but I think it was eventually exonerated. This year I have not bought any multi-purpose compost at all. I raised all my seeds (including chillis and tomatoes) in Levington's John Innes No.1 and transplanted the seedlings when ready into John Innes No.2. Both of these are specially-formulated mixtures and by rights ought not to contain any of the recycled garden waste that is the putative source of the weedkiller. But I'm still getting problems!


The most obvious sign of the issue is that the leaves of the plants become distorted and curl underneath themselves rather than standing out straight. A certain amount of leaf-curl is normal - it's associated with temperature differences between day and night-time temperatures - but this is worse than that.





In extreme cases, the plants hardly form leaves at all; instead they produce what looks like fern fronds. Fortunately none of my plants this year are as bad as that - yet - but if you want to see what I mean look at this post from a couple of years ago: Contaminated compost


For future reference this is what I have grown my tomatoes in this year:
1. Seeds sown in Levington's John Innes No.1
2. Seedlings transplanted into individual pots containing Levington's John Innes No.2
3. Plants transferred to big containers with an equal mix of: Melcourt Sylvagrow peat-free growing medium, Norfolk loam (purchased) and home-made compost.
4. At planting time I added pelleted chicken manure and Growmore general-purpose fertiliser.


In case you're wondering, No, last year's contaminated compost (the stuff used for growing the tomatoes) did not go into my compost bins. It went to the tip.




It's hard to know where the blame lies this time, but I'm considering the possibility that traces of the weedkiller could be lingering in the "hardware". I am using the same pots, the same canes and the same metal cane-supports as before. I washed the pots and supports pretty thoroughly, but I didn't think to wash the canes! Apparently these weedkillers are so powerful that to do the sort of damage I'm talking about, just one drop diluted in the amount of water contained in an Olympic-sized swimming-pool would be enough! Is it possible / likely that the canes have absorbed enough of the contaminant to still do damage now?


Significantly not all of my tomato plants are affected, at least at present, and (as far as I can tell) none of the chillis.


This "Primabella" plant look OK, with no leaf-curling


The chillis were sown in the same John Innes No.1 and planted in the same John Innes No.2, but they have not had any of the home-made compost, loam or Sylvagrow and they are not supported by canes.



I know there is nothing I can do about this problem now. The damage is already done before you can spot the effects. I take comfort from the fact that I know from experience that I will probably still be able to get a reasonable, even if smaller than usual, crop of tomatoes, and (allegedly) the weedkiller is harmless to humans (I'm not 100% convinced of that). All the same, it's hugely disappointing when I thought I had done everything to avoid being hit by this same problem again. It's getting to the point where I may have to give up growing tomatoes all together, which I really don't want to do.

19 comments:

  1. I have just been looking at my tomato plants in the greenhouse, several of which have furled leaves exactly like your picture. The affected ones haven't flowered yet. The outside tomato plants which are in a different compost have not furled at all. In your experience will the affected ones not fruit?

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    1. Hi Catherine; I think that even if your tomatoes are affected by the weedkiller they will probably produce at least some fruit, but some of it may be deformed. That's what happened to mine, especially in 2014 when it was worst.

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  2. Thanks Mark, will keep fingers crossed for our tomatoes!

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  3. Oh wow- this is really interesting. I garden in a community garden with strict organic rules but we certainly can't control those outside the garden. I will have to keep an eye out for signs.

    KK @ www.preppypinkcrocodile.com

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  4. The contamination shouldn't linger in pots etc but did you compost sent affected plants from previous years as this dab perpetuate the problem. Affected leaves do usually curl upwards like a spoon.

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    1. No, I know better than that! The plants went to the tip, along with the compost. The "spooning" of the leaves only affected my potatoes (that was in 2014), and with the tomatoes it's always been curling downwards.

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    2. I thought you probably would have known better but it was just a thought. If you had grown your crops inside raised beds I could've understood it but it is very strange that it is still perpetuating in your tubs of fresh compost

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  5. The fern fronds in 2014 are absolutely shocking. And the leaf curl in your pictures are very distinctive, it's very disconcerting. Perhaps, like you think the contamination is coming from your canes, if so that is easily remedied for next year.

    We use city made compost but they only allow tree waste, assumably they're trying to avoid weedkiller contamination. People use lots of weedkiller and pesticides here. A neighbor keeps talking about spraying herbicides on her walkway that runs next to my garden.

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  6. Oh my, you have GOT to be kidding me! Well, at least it seems that you are in better shape than you were last year. You may be frustrated now, but I imagine that next year, you will have resolved this issue (and those canes will be in the trash) as every year you have seen an improvement in the number of plants affected and the severity since "the" year in 2014.

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  7. For the weeds in the walkway person, I kill weeds among paving stones with boiling water. You could pour boiling water on the weeds in the middle of the night and then your neighbor won't want to use the weedkiller.

    I am an organic gardener and I have seen leaf stems on my tomato plants act like that but didn't know the reason. I guess I thought it was pest injury or a virus. Now I have a new suspect: weedkiller!

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  8. It must be so frustrating when you had hoped to have done everything to prevent this happening again! Sarah x

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  9. My tomato plants have also suffered from serious leaf curl when planted in Levingtons Gro-bags. I planted 9 beautiful healthy plants grown from seed by a friend into 3 bags and every plant developed leaf curl. I planted 3 more plants in a much cheaper Homebase Gro-bag and they are completely healthy and strong. I threw away the infected plants and bought 9 more but planted them again into the Levingtons bags, just adding some fresh compost around the root ball. The same thing has happened to all 9 plants, but some of them have produced tomatoes so I am just waiting to see how they develop. I thought the leaf curl was due to extremes of temperature or perhaps lack of water, but having read the above comments, I have now realised it is a problem with the compost. I am considering making a complaint to Levingtons.

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    1. Hi Steph; I'm sorry to hear that you too have had major problems with commercial compost. It's getting really difficult to buy compost in which you can have any faith. Good luck with making a complaint to Levingtons. I'll be interested to hear what they say.

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  10. Hi. I have the same problem with 5 Levington grow bags - the standard ones, not the deep tomato ones. All the plants in those 5 bags are deformed with curled fern-like new growth and deformed lower leaves. Very few and very late fruit. At first I thought it must be some sort of virus until I noticed it was ONLY my Levington bags. The cheapo extra bag I picked up in Lidl because I couldn't stand to compost my 'spare' seedlings is turning out to be a godsend. Thy are coming on nicely.

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    1. Oh No, not another! The big companies like Levingtons still deny they have a problem.

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    2. Can I add you to the vivtim's list on my website? If so please email me (address can be found on my blog).

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  11. Yes, this has been an issue for two years with scott-levington standard grow bags. After presenting evidence, (samples, photographic, observational and empirical) supported by scientific evidence Scott-levington finally agreed that there was an issue. They would not identify the contaminant other tan to say 'weedkiller'. The trials I conducted suggest synthetic auxin with high residual activity. I am informed that Scott-levington have quintupled their testing!

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  12. I had trouble with Levingtons Grow Bags in 2016 and lost my whole crop of Tomatoes, Chilli's and Cucumbers, Scotts eventually compensated me the bare minimum for lost crop after admitting to "issues" with the bags. Part of my compensation was Vouchers for 2017 Grow Bags. How foolish was I to use them. This years crop (20 Grow Bags) are again showing classic Aminopyralid damage, I have 20 plants growing in my own homemade compost that are absolutely fine! Scott-Levingtons are not interested, the Rep has had my phone number since last week and assured our supplier he would ring us. We were promised by our supplier that Levingtons had sorted out their "issues". The fact that they are selling a growing medium for plants that is contaminated with plant herbicide is a dreadful irony, they are contaminating the Human food chain with Herbicide, who wants to eat contaminated produce? I wish I knew what course of action to take.

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    1. Isn't it sad that the producers know full well that there is a major problem, but won't do anything about it. "Profit before Planet" as they say... As a private individual, there doesn't seem to be much one can do. I shall certainly be publicising the issue repeatedly, on my blog.

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