Clopyralid is the common name of a herbicide that kills broad-leaved weeds such as dandelions, clover, and thistle. Clopyralid contamination of yard debris compost emerged as a problem in Washington State in 2000 and 2001. Clopyralid has since been banned as a lawn herbicide, removing the risk of contamination of yard debris compost. Because clopyralid is still registered for use on grass hay and some grain crops, the risk of contamination of some animal manures with clopyralid remains.
Thinning is the term foresters apply to removal of some trees from a stand to give others more room (and resources) to grow. It is a tool for improving timber value, making sites more productive, and — perhaps most commonly — for keeping trees healthy. Learn when to thin and how much to cut, and learn why the answer may be "it depends."