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Contaminated manure

t.d.gibsont.d.gibson Posts: 4
in Problem solving
I grow dahlias and have built up a reasonable collection over the years. This year I decided to use the free manure from my next door neighbours stable rather than buy compost like I did in 2021. Consequently all my dahlia beds got a good amount of well rotted manure dug through and I thought this should put plenty of goodness back into the soil. The tubers were planted out mid-may and all seemed well at first, if a bit slow, but then with growth well established on many plants the top leaves started to become deformed and curl. Also some plants that had started slow never really grew proper leaves. So I did some research and found a really nasty issue that I had no idea about previously. It seems that some herbicides used to destroy broadleaf weeds (e.g. aminopyralid) can come through into manure and destroy your garden. It looks like the manure produced from my neighbours horses have this issue. So what to do - my dahlia collection is in some cases irreplaceable as I've had some of them 20 years and nobody knows what variety they are now. Not all the plants are affected badly, so I wondered if there is any way these can be rescued or if cuttings taken from seemingly unaffected stems would be viable? I am a biochemist by training, so I know somethings about the chemistry of herbicides and how these act, but I'm not sure if once affected, a plant can recover.  I thought if the beds are inundated with 1000's of litres of water the very water soluble herbicide could be leached out of the soil, however I'm not sure of this. So I would be grateful if anybody out there can help.  
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  • ObelixxObelixx Posts: 30,090
    his problem has been around for some years, particularly for organic allotmenteers and small-holders using manure rather than chemical fertilisers.    I suggest you read this article, tho it is old now, and then maybe contact the author or do more research but I don't think just watering it away is going to work.  

    I'd try digging up all your tubers, rinsing the roots clean and potting them up or re-planting in un-manured beds.   You also need to have a ord with the stables about whether they produce their own hay and straw or buy it in so you can trace where the aminopyralid has been used and contravened the rules for its use.

    https://www.theguardian.com/environment/georgemonbiot/2011/jul/15/vegetables-disease-aminopyralid-pesticide  
    Vendée - 20kms from Atlantic coast.
    "The price good men (and women) pay for indifference to public affairs is to be ruled by evil men (and women)."
    Plato
  • t.d.gibsont.d.gibson Posts: 4
    Thanks for the rapid responses.  The organicgrowersalliance is particularly useful. 
    I've already read the article in the guardian thanks.  Now the affected beds total up to 85 plants, so digging them all up and re-planting is not really an option as I don't have any other flower beds available. Some of the tubers are in excess of 2 kilos in weight as well.  The stables in question are owned by my neighbours daughter and all she does in buy in feed for her 2 horses and the dung heap at the back is just the accumulation of stable waste over several years. So I believe the aminopyralid contamination has come from some hay feed or the straw bedding thats slowly concentrated in the anaerobic rotted manure at the base of the stack. It seems that aminopyralid is very water soluble and doesn't bind to organic matter or soil, so rain over the years the stack was there has almost certainly dissolved the aminopyralid off the upper layers and leached it to the lower part of the stack. Aminopyralid is more stable in anaerobic conditions. 
    The rationale of water inundation was down to the fact that leaching and run off is one way the concentrations of aminopyralid in soils gets reduced, however the question I really want to know is once a plant is affected, can it be saved or is it doomed?
  • ObelixxObelixx Posts: 30,090
    I guess if you can't dig them up and pot or re-plant you'll have to play the "wait and see" game.   I'd also try taking cuttings as insurance, assuming you have some normal stems.

    Do also contact the manufacturers of AP and see if you can claim some compensation.  Try outing them on Facebook and Instagram if you use such things and get no joy. 
    Vendée - 20kms from Atlantic coast.
    "The price good men (and women) pay for indifference to public affairs is to be ruled by evil men (and women)."
    Plato
  • reimonnjreimonnj Posts: 2
    I’m having the same issue with herbicide residue in horse manure that I applied to my vegetable garden this winter. My broad beans are severely stunted with the characteristic curled and twisted leaves. How are things going this spring? What steps did you take last year? Wondering what works and what doesn’t. Thank you!
  • DovefromaboveDovefromabove Posts: 88,147
    edited May 2023
    Where did your manure come from?  There are regulations which do not permit landowners/users to allow manure from stock grazed on pasture treated with aminopyralid to be taken off that particular landholding. 

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.





  • bertrand-mabelbertrand-mabel Posts: 2,697
    Not to do with manure but decades ago we were given a bale of hay from our next door neighbour and used it to go under the outdoor strawberry plants. BIG BIG mistake. We are still having to keep on checking for sow thistle in and around the same area. We didn't have them before and yes I know that seeds can blow in but the amount of plants can only have come from the hay. Leave just a small root and they keep growing. It is so easy to think that you are doing the right thing for your garden and then find that you haven't.
  • MikeOxgreenMikeOxgreen Posts: 812
    If it's put into a compost heap it lives, but if it's spread on the land it doesn't.
    Basically write off this years growing certain things wherever you've spread it and let microbiological activity sort it out.
    Some things are not effected by it so grow those this year.
  • bédébédé Posts: 3,095
    I assume that healthy growth on your dahlia tubers have avoided serious damage.  You should be able to propagate from these.

    It's not just horse manure.  Reuthe's nursery a few years back had a delivery of ex-brewery spent hops delivered.  It was dumped near some stock rhododendrons.  They believed it was copper contamination that killed their plants.
     location: Surrey Hills, England, ex-woodland acidic sand.
    "Have nothing in your garden that you don't know to be useful, or believe to be beautiful."
  • FairygirlFairygirl Posts: 55,117
    That's my thought @Dovefromabove.
    I'd never get fresh manure from any outlet I didn't have good knowledge of already, and would be careful how I used or stored it . 
    It's a place where beautiful isn't enough of a word....



    I live in west central Scotland - not where that photo is...
  • SkandiSkandi Posts: 1,723
    I'll take manure from anywhere, but I always test it. I get it fresh so I mix a sample with a bit of soil and plant some pea and bean seeds, if they come up and do fine for a few weeks I let the entire thing rot down and use wherever I see fit. If I get a batch that is contaminated it'll get spread on the field where it won't do any harm to the barley and rye that gets grown there.
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