Raised gardening beds are practical for gardening in areas that have poor water drainage. Raised gardens allow for better drainage, as well as improved moisture retention and better root development due to less soil compaction. Easier weed control is another big benefit to raised garden beds, including easier accessibility. They also enable you to plant earlier in the season, because the raised beds have warmer soil in the spring. Constructing raised gardening beds takes some planning, the right tools and materials, as well as some physical labor.
Decide where you want to locate your raised garden bed. Think about the types of plants you will put in your raised garden, their water needs and what kind of sun exposure they'll require. Generally, most raised garden beds are constructed in full sun or a spot that receives direct morning sunlight and partial shade in the afternoon.
Mark the perimeter of your raised bed using stakes and twine. Place stakes into the ground where you want the four corners of your garden bed, and then tie the twine from stake to stake so that you've outlined the bed site. After you have your desired layout, measure the dimensions of your bed site.
Cover the site with a thick layer of organic mulch or black plastic for one month to kill the existing grass and other vegetation. Then, till the soil well down into the ground approximately 6 inches.
Construct your frame using the measurements of the bed site that you staked. You can build the frame using stone, brick, landscaping blocks or rot-resistant wood, such as redwood. If you use wood, cut it to fit the dimensions of your bed site using a circular saw. If you use landscaping blocks, simply stack them in a staggered fashion to create your frame.
Build the frame so that it is at least 6 inches high and less than 4 feet wide. If your bed is longer than 6 feet, fasten the sides together every 4 to 6 feet using cable or galvanized nails.
Fill your raised garden with soil. Mix one part peat moss, compost or other organic matter with one part sand or perlite and two parts topsoil.