Raised-bed gardening is an old and simple technique of raising a portion of soil in the garden so that it is higher than the rest. Raising a garden up provides a lot of advantages--for example, it makes the garden easy to work on all sides without stepping on, and compacting the soil. Soil raised up from the rest retains warmth longer into the season, extending the period you can grow in and increasing yield, according to the University of Ohio Extension. A simple raised ground bed does not require building a wooden frame, just a shovel and a tiller.
Determine the size of your raised bed, taking into consideration how far you can comfortably reach into the gardening space. The maximum width of a raised garden should be 2 1/2 feet if you only have access to one side, and 5 feet if you access from both sides of the garden, recommends the University of Minnesota Extension.
Dig down a spades height into the garden and remove the soil. Till the soil underneath to a depth of 10 inches with the rototiller. This aerates the soil and increases the depth to which the plant roots can grow. Fill the hole back in.
Add four to 6 inches of compost, commercial soil, or well-rotted manure and till it into the soil underneath, says the University of Minnesota. Taper the sides of the garden so that they are at a 45-degree angle. Let the soil rest for one to two weeks before planting.