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Manure problem 2010

I was really hoping that by 2010 this was going to be a thing of the past but had emails from a few people who suspect that they are new or repeat victims.


It's important to bear in mind that problems may be caused by things other than herbicide contamination but if you suspect - check with the photos here) that you have used contaminated manure then you should:


1. Keep a sample of the suspected manure - this may mean taking some from the ground

2. Contact your supplier and ask them the questions here

3. Contact the CRD and DOW  to inform them of your suspicions preferably including photographs

4. Follow the advice here

5. You may wish to carry out a soil test see here


My comments are as usual in green


William from Peacehaven, East Sussex sent the photographs on the left and wrote:

"It looks like I got myself a batch of very contaminated horse manure last autumn.  These pictures are of my potato crop planted at the beginning of April 2010, using the newly sourced manure.  I still have a few barrow loads left.   Any advice gratefully received.  Manure also used on runner beans – would they be edible if they manage to grow?"

He reported that he obtained horse manure last autumn from a very small stables in the countryside between Peacehaven and the town of Lewes.  His compost heap is still half full with the stuff. Unfortunately he was one of several domestic gardeners who were bagging up manure at that place, so the problem isn’t going to be confined to him.

If William's beans are affected as ours were it is unlikely that they will recover and go on to produce beans but if that does happen we are told by the experts that crops are safe for human consumption.


Andrea from Shardlow Derby. A Just emailed to say, " We have contaminated manure. Many people have it, all from the same source.  I spoke to the farmer's wife who said that they had been told to check their manure source as they had problems last year, but they didn't and kept on selling it to locals.  I'm a bit annoyed that they didn't do anything - do you know if there is any legal recourse? just a thought.... Anyhow - you'll need to add another colour pin to your map for 2010!






John from Sandwell was first affected by this problem in 2008 - he emailed to say "I have attached a photo of my affected beans (on the right) - only two or three, but this is in land unaffected previously. The seed was collected from beans on the School Garden, where manure was applied in 2008. The beans providing the seed were themselves affected, and my sowing of their progeny was out of sheer cussed interest to see what would happen. And lo and behold!"

This seems to show that contamination is carried over into the plant material of crops grown in affected manure. On our site we had a conundrum last year in that one plot holder's potatoes showed the effects of herbicide contamination. This was on soil that hadn't been treated with anything at all for years. The only thing we could think of was that the seed potatoes had been affected in some way during their growth but we never managed to get to the bottom of this as the plot holder hadn't kept the grower's reference - who does?

Plant material from affected crops should not be composted - this includes any 'volunteer' crops such as where potato tubers from affected plants have been accidentally left in the ground. This applies even if the plants look to recover from the contamination.







Peter from Norwich says," I'm suffering from the effects of this chemical. Horse manure about 5 years old has wrecked my spuds and tomatoes. Organic for 40 years prior to this disaster. So if you are updating your map this year please add this location. Thanks for the info,"

Unfortunately the map is being updated. This report shows just how persistent the chemical is and that the stacking of manure doesn't render it safe to use.


Liz reported from Midmar Allotments Association in the south of Edinburgh "About 10 days ago some of our members reported abnormal growth on their potatoes. Subsequently we have identified abnormal growth in potatoes and raspberries and death of pea and bean plants.

It would seem that the cause is contamination of a batch of horse manure which was ordered on behalf of our members in the early spring. We have researched the problem and it is most probably due to the herbicide, aminopyralid; this is used on pastures and hay fields to kill off broad leaved weeds such as docks and ragwort. I have not yet spoken to the stables as I would first want to talk to as many members as possible who have used this batch of manure. They may be unaware of using any contaminated haylage.

Has there been any other recent reports? I know the chemical was first used in 2008, then withdrawn due to similar reports from allotment holders and gardeners who had spread contaminated manure. It was re-released with stricter warnings to farmers to retain the manure on their farm; I am therefore astonished that it has reappeared on our site.

Although an improved stewardship is mow in place with respect to aminopyralid there will still be lots of manure 'produced' prior to this that has been stacked in yards. As the herbicide does not dissipate when present in stacked manure it is likely that affected stacked manure could cause a problem for a few years to come. We also have to hope that the stewwardship is effective.

Liz further reported - "We have approx 40 plot-holders who are affected. The local Green MSP contacted the local press and an article may appear in the Scotsman newspaper. I have not found any organisation which would help with an analysis. SEPA (Scottish Environment Protection Authority) are not interested. I am sure the problem is due to Aminopyralid as the description of its affects exactly fit our observations. Those of our members who have endeavoured to grow their crops organically are particularly dismayed.

Testing to try and prove the existence of aminopyralid is very difficult die to the very low levels of the chemical needed to be present to cause problems. Testing is also very difficult. You can carry out a 'bean test' but any testing can only really prove that aminopyralid is likely to be present as a negative result.


Kev who has a plot in a village near Mansfield reported, " A fellow plot holder thinks his tomatoes are being affected. When he planted his toms he dug the planting hole and then lined with cow muck. What he wants to know is if he dug the toms up and replanted into pots with just multi purpose compost would this do any good? His plants are fine apart from the top 12 inch so he is hoping that if he did the above would the plants recover?" There are now 7 people on Kev's site affected.

It's worth a try!


Nick from near Southampton has been badly affected by suspected manure contamination. Beans, peas, potatoes, (photo on the left) achochias, Mexican gherkins, ajipa, sweet peas all died.  He says’ “I have a small fence across my plot. One side had horse manure and the other cow manure. Although there was no cross-over everything was affected (even cucumbers, courgettes squashes and marrows which just didn't grow) on the cow manure side. However, all crops including onions, spinach, radishes, turnips and beetroot were stunted close up to the fence. In fact there was a very definite gradient upwards as the distance increased away from the fence. Also the grass path along the bottom of my site has no weeds in it for the first 12" inwards. The manure I used was produced over the winter of 2008/2009. A previous load from the same supplier of 2007/2008 vintage proved to be absolutely fine. I think I got caught out as my supplier contracts out for spraying some areas of his farm. He was totally unaware of the problem despite being a farmer for 50 years. I have explained in detail and left him to peruse the Internet information. (He sold about twenty five loads of manure each of about 5 tons over the winter).

I think my problem may have been so bad as we are on a plot new at the beginning of 2009. I dug in 5 tons of the stuff mid winter (Dec/Jan 2009/2010) as the soil was so poor. This being over about 2/3 of a 5 rod plot. Rather a thick application but same method worked wonders in the first season. Having dug over the whole area then rotovated it today I could see many lumps of manure which had not broken down since January.

Interestingly our affected manure didn't seem to break down as quickly as usual either.


Simon from South Norfolk reports, "We currently have the same problem This is our third year of growing with mixed success as the land is light, dry and plagued with moles and horse radish (and now hormonal manure)!"


Mary from Southampton emailed to say, "A few of us on our allotments have had potatoes and beans ruined by manure brought in last autumn from a farmer who has been supplying us for several years. Interestingly, it seems that only some of his manure was contaminated. When I phoned him at the beginning of the trouble he said he only uses 'Transfer' and has done so for years, but he buys in his straw (for the cows). A guy from Southampton council came to look and confirmed hormonal weedkiller is the source".

DOW should remove the manure get the council to contact them - it will have more weight coming from them. They should also let the CRD know of the problem too. Are you in the NSALG? - if so let them know too.

It is unlikely that the contamination has come from straw as straw comes from cereal crops and Aminopyralid isn't licenced for use on cereals - if he uses hay it could come from that.

We had the same problem some manure being more or less contaminated or causing no effects at all. I think it's down to where on the pile your manure came from if the farmer uses different sources for his haylage or the cows browse different areas - some sprayed/some not.


Robert from Tonypandy in Wales posted a guestbook message saying, " This year my allotment has been decimated by aminopyralid contaminated manure, I also lost all tomato and cucumbers in the green house due to using B and Qs organic feed left over from last year. Apparently this was removed last year but I missed the announcement. Being organic is getting harder!"


Dhink from Chatburn, Lancashire told us via the our old visitors’ guestbook that he/she was a first time allotmenteer trying to be organic and now has been affected by the aminopyralid problem. Manure from the site midden was used and three people on the site are affected. The worst affected potatoes have been pulled out.  Other plants  may also be starting to be affected.  Dhink is worried about eating any of produce as I hay from midden has been used as a weed suppressant round soft fruit, broad beans, caulis, salad and broccoli.

I can understand the worry - experts tell us that the herbicide does not pose a problem to human health. Broad beans are sensitive to the herbicide as are raspberries so I would expect them to show some signs if they had been affected by herbicide poisoning. You could mix some of the hay with soil in a plant pot, fill another plant pot with 'clean' soil and plant a bean seed in each pot to see what happens. Not conclusive but may confirm if there is a problem. I'm no expert but I wouldn't think that contamination could spread from the manure to the straw unless manure was mixed in with the straw.


Shirley from Sheffield emailed to say: "I am afraid that I too have become a victim of contaminated manure on my allotment. I have been using manure from a local stables, which is based on sawdust rather than straw and which was delivered for free removal by allotment holders last autumn/winter. The only positive sufferers so far are broad beans, but sweet peas sown in the same manure are also beginning to show signs. Other crops also grown in the manure (onions, brassicas, spinach) seem to be OK, though I have used it for tomatoes which may begin to show symptoms soon. One thing I can't find on your excellent web-site is whether or not it is safe to eat any affected produce. I seem to remember in discussion last year that it was decided it was safe for human consumption, but I would be grateful for your advice. Your details were given me by Garden Organic who identified the problem for me.

According to the experts, vegetables grown with affected manure are safe to eat. and milk from cows fed treated silage is safe to drink.


Andrew from Cambridge emailed to report that: "It is now late June 2010 and my garden near Cambridge would seem to have joined the great and the good who are working land contaminated with



As many contributors seem to have experienced over the last couple of years, symptoms of curly leaves first appeared with my broad beans back in April this year when the plants were about six inches high. The problem soon manifested itself amongst phlox, geranium, honey suckle, and roses. More recently my tomatoes, runner beans, and pumpkins are beginning to look depressingly similar.


In my case, the problem is to some extent of my own creation in that I garden virtually organically, double digging the veg patch, and mulching the ornamentals every year with homemade manure, which comprises homemade kitchen/garden waste, leaf mould, and at least 50% horse manure from my horses. The horses are out to grass throughout the year, but their diet is supplemented with horse feed. The fields are not regularly sprayed, and have not been sprayed for four or five years, when they were spot sprayed for nettles and thistles with a knapsack. So the problem must lie with the chemicals used to produce the horse feed. I have been using this method for many years, and 2010 is the first time that I have experienced this problem. I should perhaps add that my system of composting the manure runs two years in advance, so that I am possibly experiencing the difficulties which faced other correspondents in 2008.

This said, I seem to have a reasonable crop of broad beans, which according to the DOW web site are safe to eat and have been enjoying spinach and salading, grown under similar conditions since March, so hopefully the year won’t be a total write off. Rather annoyingly, I chose this year to reorganize some of the ornamental boarders, and have spent some money and time buying plants and preparing the soil to really help them get a good start. Now I am hoping that they will weather the storm and rally later this year or next, but am considering digging up and replanting the new roses in the hope of rescuing them. To this end I have attached some ornamental photos of phlox, and rose with honeysuckle, since you have plenty of bean photos like mine!


If you can remove as much of the mulch as possible it may help the plants to recover.


Elizabeth from the Isle of Wight emailed to say "I just wanted to add my name to the list of saddened gardeners who, like myself, purchased a load of well rotted farmyard manure earlier this year. I spent hours heaving the stuff into 3 raised beds and then digging it all in with bags of purchased compost. Early in June, the first crop to be affected were runner beans and French beans (stunted, flowering at the base of the plant but producing a few distorted small beans plus cupping of leaves which were yellow veined). Within a week the tops of my potato plants (which had been doing very well) started showing signs of curled up fern like foliage and also the same with my tomatoes (various varieties). The Italian tomato plants have the curled up leaves and a strange formation of flowers - normal ones plus one huge flower much like a sunflower!! I have been in contact with a Mr. Steve Higginbotham at and after seeing my photographs of my crops he has agreed that they show evidence of Aminopyralid contamination. He says the crops are safe to eat. So does the Pesticide Safety Directorate. But, would you feed your children or your elderly parents or indeed anyone you loved, these crops? How dreadful would you feel if, some years later down the line, you or one of your family developed a condition related to this industrial herbicide? It's not something you really want to second guess. I am devastated. I have worked so hard this year and it is all for naught. This industrial herbicide is now in the food chain - and it also now poses a problem in terms of getting rid of the affected plants. As for next year, how can I be sure of buying uncontaminated manure?


Really there isn't a certain way of ensuring that you don't obtain contaminated manure but you can cut down the chance of this happening if you ask the right questions as indicated on this page of my website


Laura from Alness, Ross-shire, Scotland emailed to say " I've been researching the manure issue and found your site today.  Thanks for doing all the hard work.  I've posted on the blog some comments/observations and am still unsure which is the culprit when others and yourself discuss varying effects on same crops.

I'm in northern Scotland, so thought you might like to hear from up here.   I got my manure from the local allotments and in March spread it on all my beds.  I spoke with their committee organiser yesterday who said they and himself have all been using the same manure heap for the past two years with no trouble.  they get it from a livery stable up the road.   I checked out the crops on the allotments this morning and all looked absolutely fine, especially the potatoes.  However, not much growing but tatties, brassicas and soft fruits.  My brassicas are all thriving, as are my leafy greens.  They had some squashes in one or two beds, but they're not very far advanced and its colder here, so not surprising.  No greenhouses, so no toms on display, but he did mention that this year everyone's toms were rather yellow and slow growing. one chap had some broad beans, and while they didn't look anything like my poor pathetic stalks, I did notice that the very upper leaves did show signs of curling this year I used my own homemade compost from the end of  last year and mixed 50:50 with B&Q peat free, plus a bit of Levingtons peat compost.  Nearly all my plants were sown or potted on in this mix.  The squashes, toms, aubergines & peppers were all successively potted on before some were planted out in manured soil  while others were put in big pots with a different source of manure.  The peppers and aubergines left longest in pots and then planted out in planters, rather than ground soil are doing better than those in ground but then these were also planted out earlier and were thus more exposed to colder temps.  My point being that crops planted out earliest in the manured soil, like broad beans, peas, french beans and courgettes have all showed the severest signs of the herbicide effect.  If it's the manure, then how come the allotment people are not experiencing the same problems?   If its the peat free compost from B&Q, then how come those plants grown longest in the mix appear to be the least affected?

You certainly appear to have a conundrum although it is possible that only part of the manure heap was affected - we had some people using manure from the same source as us having no problem. Was the B and Q compost old compost as they did recall batches of compost that were affected with herbicide last year?


Felicity from Oatlands Park Allotments in Weybridge has been in touch to report that she is another contaminated manure victim just to add another spot to your map! She says, "I have discussed with manurematters/DOW, and with the RHS. I have potatoes, raspberries and beans all affected in the usual ways, plus a suspected sunflower or two!

My manure came from an large equestrian centre in Leatherhead, where there are loads of livery customers, so I imagine their feed suppliers are many and various. I have not been able to get in touch with them as yet, but I did have an email conversation with them in spring 2009 before I started to use their manure. I only asked whether their pile might be contaminated and was told not - but really, how would they know? Anyway, I have collected from there on many occasions last year and this, so am not sure whether this is an old (but stored in my compost heap) or new problem.

I have been taking photos of my beds since I started the plot in 2009, and have one combined photo that you may find interesting.



The left picture shows a bed containing my very first manure pickup from this stables. I had no compost heap at the time, so that's where I put it. Shortly after that, the bed was covered with planks waiting to be made into bed edges, and so it stayed, relatively dry for all of last year. This spring, those bed edges were made, and I then dug over this patch, incorporating all the manure across the whole bed. I was impressed by the number of worms in the 2/3rds that had had manure on all that time.


The right picture shows the same bed later this year, with potatoes growing in it. The area of more-affected growth exactly matches the area where the manure had been sitting for almost a year. I believe this supports the following two-stage process that is required to decompose the aminopyralid:

  • AP is firmly bound to plant cellulose and is only released once the cellulose is broken down, particularly by worms
  • AP is decomposed (and made safe) by soil microbes


While I may have got the details wrong, it highlights the delayed nature of the effects, in that the AP is only released under certain circumstances and perhaps many years after use on the hay fields. The danger for our crops is between those two stages. In my bed, I fully expect the 'good end' to become the 'bad end' as worms get to work. The potatoes are still in the ground, but I will dig over at some point and see what the difference is in tuber production, but I suspect I won't get much out of it. I am also doing an experiment with runner beans!

On a slightly different tack, we are advised not to put affected plants in the compost heap. I am not sure whether to worry about this, as I suspect that the concentration is much reduced. But I have to ask whether unaffected plants are just as 'dangerous' to the compost heap - although they show no effects (eg, my squashes are disgustingly healthy!), surely, like grass, their cellulose will still have AP bound up with it.

Your experiences DO demonstrate how difficult it is to obtain safe manure even when you ask the right questions. It also shows that contaminated manure can be obtained from sources that have been safe in the past and may be again in the future - it depends what has happened to your supply as there no consistency in the supply chain. Also of all the plot holders obtaining manure from the same supplier some were more affected than others - in fact some weren't affected at all!This is why we are avoiding using it. On our site we all noticed that the problem was most severe where we all stacked our manure - not for as long as you did but for a few months. The manure doesn't break down as quickly if it is kept dry which is why the problem persists for even longer if the manure was put in a polytunnel or greenhouse and left. This needs to be well watered. The plants that are unaffected will have absorbed some of the chemical which is why the grass that was unaffected contaminated the manure so if it is composted it will more than likely cause a problem. Our potatoes f did grow through the problem and produce quite a good harvest but then we had the do we eat or not problem? Even after being told the stuff is safe - knowing your plants are affected has a psychological effect.


Frances from Exeter emailed to say – I am sad to say the herbicide problem is still very much alive. I was late applying my manure and only added it in Feb/March to the top of the soil where it lay prior to planting my potatoes. The manure did not decompose into the soil but grew crispy and was very difficult to handle. I have actually removed a lot of this and put it into an  empty plastic compost bin thinking I would let it compost down for next year. Alas this has not saved me in any way as my potatoes are completely infected.

At first I was advised it was frost when the leaves started to curl but now I can see by your photos that it is more than that.

I planted spring broad beans and my whole crop is showing leaf curl. My peas which I grew on in pots and then planted out, have also died. Unfortunately, prior to the realisation of the enormity of the problem, I had put my runner and French beans in and they are also dying back.

The general opinion here is that I planted my crops too soon after laying out my manure which as a novice allotment holder I was ready to believe but having read your blog, I now see that we have created a major problem on the site as to when we can actually start using our allotments again for growing chemical free food.

There is a mixed response to the effect of this manure across the allotment. Some are showing no effects  at all and they dug their manure into the soil prior to Christmas. Only the people who left it until January / February are suffering now.

I know I won’t want to eat this produce, but  what is worse is that the farmer who does not spray but must have bought in animal feed over the extremely cold winter, runs a dairy farm so how will this affect the milk.???   Probably too late to think along those lines as the goods have  already been consumed!!!

What I need to know now is where do I go from here?   How can I be absolutely sure the soil is free from chemicals in order to commence planting again?   Any advice or new information would be useful.

Many thanks for all  the work and research you have put in, it has proved very informative. At a time when we have all chosen to grow our own fresh produce, I am now left feeling very guilty about contaminating my much sought after plot.


Don't feel guilty as people growing for years have had this problem and it seems some of the seasoned plot holders on your site were unaware of the problem.

When we were affected plots on our site had variable problems even though they obtained manure from the same source but this isn't surprising as it could be that only some parts of the farmer's manure pile was affected. During the course of creating the pile the animals may have fed on different fodder etc.

Don't compost the manure though as this will not solve the problem. The chemical will only break down once the manure is incorporated into the soil as it needs soil bacteria to break down the contamination. One reason that the people who left the manure until Jan/Feb to dig it in were more affected could also be because the manure that was dug in straight away could have had a chance to break down over autumn etc as the soil bacteria would have been given a good start.

We were free of the problem by the following season (although volunteer potatoes did show signs of being affected) but this varies as I do know of some people who had an ongoing problem the following year. It really depends on the degree to which the manure was contaminated and the speed of breakdown. Where manure was put in a polytunnel the problem took a long time to be resolved. The best thing to do is to remove as much of the manure as you can - which you have probably already done - turn the soil as much as you can to incorporate as much air as possible as this will speed decomposition. As for getting rid of the manure - you can arrange for DOW to collect it or it can be spread on grassland if the farmer has somewhere he can spread it away from his livestock.

To be honest the only way to tell whether your ground is 'clean' is to grow something that is sensitive to the chemical and see what happens. The problem is that the contamination could be patchy just in the same way as the plots on your site have been affected to varying degrees.  I know you are wary of eating anything grown on affected land but some plants are not as susceptible to the chemical and any brassicas or squash etc should grow OK even if the soil isn't totally clear of the problem.










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Our Plot at Green Lane Allotments Blog  | A Gardener's Weather Diary  | School Vegetable Patch Website


© Our Plot on Green Lane Allotments - Please email me if you wish to use any of this site's content