Several years ago, a fellow Master Gardener told me, “Never leave bare ground.” Such a simple statement, but it may hold the answer to many of our garden problems. Bare ground erodes and the soil washes away. The American prairies once were covered with tall grasses, but years of severe drought and failure to adopt farming techniques that would prevent wind erosion destroyed them, allowing the topsoil to blow away. All that was left was the giant Dust Bowl of the 1930s. Your yard won’t turn into a dust bowl if you leave bare spots, but some of your soil will blow and wash away if you don’t have plant roots to anchor it. Removing several ailing shrubs or a bed of perennials past their “use by” date without immediately replacing them with another species isn’t likely to cause permanent damage, but such actions nonetheless have consequences. A food source for many birds and habitat for insects and small animals may be destroyed and a small amount of carbon dioxide released from the soil w...