A raised bed garden is when a garden's soil is slightly raised up from the surrounding soil, creating a small area in which to plant. Ohio State University Extension suggests the bed being no wider than four feet, making raised beds ideal for small gardening areas. Raised bed gardens have better drainage, higher yields, expanded growing seasons due to heat getting trapped in the soil and ease of maintenance, says the University of Missouri Extension.
Dig a 4-foot trench down one spade head length and remove the soil from the trench, says the University of Missouri.
Till the trench made and then add the topsoil removed earlier back to the trench and mix the soil together. Tilling allows for deeper root establishment, says the University of Missouri.
Place railroad tie or pieces of timber, cut to the size of the trench. Bury half the bottom stake and pound in rebar 12 to 18 inches into the soil to hold the timber in place, recommends Texas A&M. Place more timbers on top, drilling holes in each layer of timber and securing it with more rebar.
Drill a hole in the side of the timber to allow for extra drainage, placing copper piping into the hole to resist decay.
Fill the raised bed with soil for the plants. Texas A&M recommends a sandy clay loam soil for the best drainage and water retention qualities.