double-digging n.— «The two have employed a practice called “double-digging,” which involves digging up the top foot of soil, tilling the bottom part of the soil underneath and then replacing and tilling the top foot.» —“Yard...
volcano mulching n.— «I have seen some landscapers use very deep layers of mulch—a foot or more in tight rings around trees and shrubs. Is this a healthy practice?…This is sometimes called volcano mulching because of the steep sides...