Some gardeners prefer a soil preparation technique called "double digging." Double digging is a process that aerates both the topsoil and some of the subsoil. It works the soil to a much deeper level than normal tilling or digging.

See Step by Step for instructions on double digging.

		Advantages of double digging: most herbaceous plants, particularly perennials, greatly benefit from the rich, deep soils.
		Disadvantages of double digging: the process is strenuous, labor intensive, and expensive, given the amount of organic matter that is incorporated into the soil.

"You will hear a lot about something called double digging . . . it is said it will double the life of your garden, but it may also halve the life of the gardener." --- Elsa Bakalar