A Warning About Straw
...often applied at such high rates that certain plants won’t grow in garden soil dressed with finished compost from a mix of sources, if one of those sources is a treated lawn or field. A quick bioassay will test for this in straw: peas sprouting from soil mixed with that straw will look deformed if the field that grew the straw was treated. Browns of a similar texture from a source you know to be clean should probably be used for a control group.”...