I have just read an article that states weedkillers are getting into the bulking material in commercial compost. Since we are all being good and cutting down on the peat based composts, most of the bulk is made up from garden waste dumped at the tip. The lawn weed killers are the worst as they carry on working even after the grass has been cut and taken to the tip. I have in the past used the council compost as a top dressing, they are not allowed to call it compost but use the term soil improver. I have had good results but have often wondered why some areas had wilted leaves etc. Now I know why. Some of us wonder why our tomatoes get leaf wilt in a growbag and put it down to our own mistakes or a natural pest. Nobody blames the compost. It seems that SylvaGrow is about the only safe one. Never heard of it before today, but if the price is right, that is all I shall be using from now on.
There are no checks at recycling plants here, but over on the continent they are a bit more careful. This is not a scaremongering post, even the RHS have done tests and found the weedkiller in bags of peat free compost.