The depth and techniques that you use to loosen the soil depend on which plants you intend to grow and the condition of your soil. For your average garden of annual flowers and vegetables, for example, you can use a process called single digging to break up the top 8 inches (20 cm) of soil by using a spade or rototiller. In existing gardens with light, fluffy soil, you may be able to turn the bed with a spade without too much difficulty and minimize organic matter loss. If you prepare the soil in autumn, let frost help break up the soil clumps. Then spade again in spring and finish up with a rake.

Begin the single-digging process by removing a section of soil the width of the bed and the depth of your spade. Soon, you’ll have what looks like a shallow grave. Next, slice down into the adjacent portion of soil with the spade and roll that soil into the trench you just made. Continue this process until you have covered the garden width (or length). Finally, haul the soil excavated from the first trench and place it into the last space. After your first pass with the shovel, break up the clods and add the soil amendments and fertilizer. Then dig through the bed again, raking vigorously to break up clods and to mix in the amendments. Use a garden rake to comb through the soil and remove rocks, clods, and any vegetation or plant roots that you missed previously. Smooth the soil over the entire bed by raking, and you’re ready to plant.

Time For A Tiller

Digging a small flower bed is a good exercise program, but preparing a large one by hand in one day is almost impossible without the help of a tiller. If you need to cultivate more than 1,000 square feet (93m2), consider renting, borrowing, or buying a tiller. Lightweight minitillers are sufficient for many tilling chores. For larger jobs, look to either front- or rear-tined tillers. Professional growers usually favor the latter.

You can also have someone else till your garden. No matter where you live, you can usually find someone in your community (through the classified ads or your local garden center) who does this sort of work in the spring. Before the person arrives to churn up your soil, have all the soil amendments that you intend to use on hand. After you till the area and rake out the weeds, spread out your soil amendments and fertilizer, and till it again.

Rototillers are a handy tool for occasional use. Beware, however, that repeated use of tillers can create a hardpan layer (known as plow pan or pressure pan). Tillers promote faster breakdown of soil organic matter because of how they stir and mix the soil; and tillers cultivate soil to only one depth, so the soil beneath the tilled layer becomes compacted from repeated pressure from the tiller.

Double Digging

Double digging works the soil more deeply than single digging and is useful for deep-rooted plants or areas where drainage needs improvement. The effects of this labor-intensive process last for years.

• Mark out a bed 3 or 4 feet (1 or 1.2 m) wide and up to 25 feet (7.  ....read more