You remember the anecdote about the thermos, you put a hot liquid in it, it
keeps it hot, put in a cold liquid, it keeps it cold. HOW DOES IT KNOW WHAT TO
DO????
Wood mulch, it *keeps weeds from growing*. So you spread the recommended 3-4
inches to keep the weeds down, but any perennial under the mulch will return.
HOW DOES IT KNOW WHAT TO DO???