Weedkiller contamination of peat-free composts

[caroline7758]

Just got round to reading my January issue of The Garden and was worried to find an article about the lawn weedkiller clopyralid being found in some peat-free growing bags (sadly it doesn't name any brands) causing distorted growth on tomatoes. They say it's probably come from green waste and suggests doing a germination test. It also mentions Sylvagrow as an RHS- approved peat-free compost which doesn't use green waste.

[caroline7758]

[sunloving]

Oh dear! It's so frustrating that these products continue to be licensed despite understanding of the impact on gardeners.
Those years when we lost all our 100 dahlia varieties and couldn't grow toms beans or potatoes were frustrating ones, having your plot contaminated by chemicals you didn't use/ buy is so aggravating.
It's so hard to find a decent peat free compost in the first place without this additional issue.
I live in Ireland now and have lovely peat compost from regulated bogs it makes such a difference to seeds and cuttings. Not feeling to guilty despite being an ecologist.

[PondDragon]

It really is unacceptable that these highly toxic and persistent chemicals continue to be freely available to purchase/use by the general public. No doubt the manufacturers would argue that the small print gives directions for proper use and disposal of grass cuttings, but clearly that isn't enough to prevent residue contamination.

Apart from the actual damage caused to plants, they also have the effect of undermining confidence in the use of green waste, manure and peat free / reduced peat composts generally.

[Tee Gee]

It was something that has been waiting to happen for many years.

I recall when I was but a lad and was learning the gardening game the pundits of the day would advise you never to put diseased or  material treated with weedkiller on our compost heaps.

The advice was; always take this type of material to the council tip!

So we did and I still do but the trouble is.................this material is now being recycled!


Is it being treated properly? I seem to recall  reading somewhere that compost taken from ones garden could well be on the shelves of a garden centre within six weeks. If this is true is it any wonder that such problems exist!

Then when farmers can treat the pastures with selective weedkillers that if eaten by their livestock gives no ill affect to the animal/s but when the defecate and it lands up as farmyard manure and sold of to some gardener then it is no wonder that we gardeners suffer.


I recall the Aminopyralyd problem we had a few years ago when there was a right uproar about it. Hasty legislation was produced to ensure that such a problem would not arise again. This resulted in farmers being advised that they can not sell manure treated in this manner to the public, but do they? who polices this?


We get loads of free horsemanure delivered to our plots from a horse stable nearby. When we were approached if we wanted it we checked the material and saw that the matrix of the manure was shredded paper & cardboard so we decided to take it on board.

But I am not sure if it is truly clean for two reasons and that is the stables buy there feeding in (silage) and grazing areas are being treated for Knotweed so there is scope for it to get into this manure.


Having experienced the Aminopyralid in the past I know what to look for and I am nearly certain my Peppers were slightly affected this last season with something but what? Was it the compost I grew them in initially, or was it the manure I dig into my beds I'll never know.

I have just bought my compost in for next year (8 x 60Litre) bags so fingers crossed it is CLEAR of Herbicide residues!

[sparrow]

I use SylvaGrow and trialled it against Jack's Magic last year with my padrons. Same yields, slightly different watering. Both lovely composts, but I'm no longer using peat. Not trying to start any arguments, but I don't think it's necessary.

[Digeroo]

I had one batch of contaminated compost a few years ago, luckily saw the symptoms fast and managed to repot them.  Also had one batch of contaminated recycled direct.  I try not to buy the stuff during the early summer. 
As far as I know everyone puts their garden mowings straight into the green bin no thoughts about weed killer.
Beans are a good test plant, as is fat hen.