Raised beds for vegetable gardening are growing in popularity. “Many gardeners are realizing the benefits of this low-cost approach to gardening,” says Marlin Bates, an MU Extension horticulturist. “There are many reasons to consider building a raised bed, including higher yields, easier maintenance and longer growing seasons.”
Because the soil within a raised bed warms faster than the surrounding soil, plants can get a jump-start. Raised beds offer better drainage, reducing the problem of waterlogged soils typical of spring gardens in Missouri. “These things allow for better root growth early in the season, which can lead to healthier, more productive plants in the summer,” Bates says.
In its simplest form, raised-bed gardening is container gardening. “Whiskey barrels or similar containers can be quite productive, so long as drainage is provided,” he said.
For larger-scale gardening, you can create frames from a number of materials, including cinder blocks, rot-resistant untreated lumber and landscaping stones. Avoid using treated lumber or railroad ties because their chemical content can be harmful to the plants.
The shape of the raised bed should allow for access without having to enter. “Generally, narrow beds are useful because they allow gardeners to reach into the center of the bed from each side,” Bates says. “Just be careful not to make them so long that they are difficult to get around when navigating the landscape.”
The most important decision in the bed-making process is choosing a medium to fill the frame. “Because so many of the benefits of raised-bed gardening relate to the soil, choose wisely,” he says. “A good approach is to source some high-quality topsoil and amend it with additional organic matter.” This may include compost, decomposed plant material, grass clippings or other yard waste. Be sure to combine these materials and marry the new soil in the raised bed with the existing soil below it.
Although there are many advantages to raised beds, they tend to dry out quickly during the summer.
For more information about raised-bed construction, contact your local extension office or see the MU Extension publication “Raised-Bed Gardening” (G6985).