Raised beds improve soil drainage and increase production of your crops. They also make your crops easier to manage because the soil doesn't get compacted as easily and they require less maintenance than conventional gardens. Raised beds can be left in mounds, but to obtain a neater appearance and decrease soil erosion, you may want to make your raised bed in a frame. Frames can be made from many different materials: cement blocks, bricks, flat rocks, railroad ties, old construction materials or wood. Making a raised bed from wood is the easiest and most inexpensive type of frame to build.
Select a flat, level area that receives an amount of sunlight that is compatible with the type of plants that you are planning to grow in your raised bed. Dig the area where the bed will be located, removing soil to about a spade's depth. Then dig down and turn the soil a spade length deeper.
Calculate what dimensions the raised bed will have. A width of about 4 feet allows easy access to the center of the bed from the edges. The depth will be determined in part by the types of plants that you are planning to grow, but a depth of 3 to 6 inches should work nicely. Any length will work, as long as you can reach the center from the edges.
Cut wood to the desired size. The desired depth of your bed will determine the size of the lumber you will use. Redwood and cedar are both good types of wood to use because they are resistant to decay and last longer than most other woods.
Lay out the cut lumber to make a square or rectangle of the desired dimensions. Connect the pieces with several galvanized screws at each corner.
Level the frame by digging out some of the soil beneath it, if necessary. Make sure the lumber is securely connected. One-inch chicken wire can be spread across the bottom and attached to the sides with staples in areas where burrowing critters are a problem.
Add manure, compost or a commercial fertilizer that is high in nitrogen to the previously removed soil to encourage healthy plant growth. Turn the additives into the soil with a spade. Fill the frame with the soil mixture and mix in with the remaining soil in the bed. Rake the soil to create an even planting surface.
Sow your raised bed with seeds or transplant starter plants into the bed, being careful not to step inside the frame.
Spread organic mulch when plants have sprouted to retain moisture and keep weeds to a minimum.