Gardening in Raised Beds
When you can control soil quality, save space, and increase the efficiency of your garden, you can hardly beat growing plants in raised beds. Raised beds are suitable for all types of gardening and landscaping, and they can be built in any place in your yard--even over a concrete patio. Almost any kind of vegetables, flowers, or shrubs will thrive.
Raised beds are constructed above ground level in areas that will receive at least six hours of sun daily. They contain soil corralled by some kind of frame. The frame can be built of bricks, cement blocks, recycled plastic, rock, or wood. Construction materials are limited only by your imagination and whatever supplies you may have available. You can turn a livestock trough, an extra-large planter, a wheelbarrow, or a recycled bathtub into a raised bed. Some companies produce and market complete kits for beds in a variety of dimensions. The one concern for beds used to grow vegetables is that they be constructed with materials that will not contaminate the soil and leach into the vegetables. For this reason avoid treated lumber of any sort.
Deciding which container to use or how high to construct your beds can provide important design elements for your garden. If you construct your own beds, plan to keep them between three and four feet wide. That allows easy access to plants from both sides. The bed’s length and placement will be determined by the space you have available or your garden design. Each bed can be from six inches to three feet above the ground level, but soil 12 inches deep provides an adequate growth medium for most flowers and vegetables.
One of the many benefits of raised beds is the ability of the gardener to control both the soil mixture and texture in areas where soils are less than ideal. Should your garden contain poor soil, you can choose your own soil mix specifically for the plants you desire to grow. This can be as easy as using a good quality purchased potting soil or slightly more difficult if you create your own mix to fill it.
Because the soil in a raised bed warms up more quickly in the spring, you can plant earlier than you can plant in the ground. This can be desirable in spring and fall, but in summer’s heat higher soil temperatures may dry beds more quickly. If rainfall is inadequate, a soaker hose or a drip system can provide supplementary water. Using an organic mulch of straw or hay will also lower soil temperature and reduce weeds.
Raised beds give good control of drainage. In addition, since the gardener works from the paths that separate the beds and does not need to walk on the soil to tend the plants, this avoids soil compaction which is an issue in many gardens.
Raised beds are planted more intensively than an ordinary garden because the soil is so fertile and plant roots penetrate easily. Placing the plants closer together in a raised bed helps to create a microclimate in which you shade the soil surface thus cooling it, conserving moisture, and lessening weed growth. Planting so intensively consistently produces harvests four to 10 times greater than produced in a conventional garden. Because planting is so intensive, however, it is necessary to add compost or other soil rich in organic matter or to grow a nourishing cover crop each year to keep the soil fertile.
You can even extend your growing season further in the fall and spring by covering your raised bed with plastic or a sun resistant growing cloth. Attaching PVC pipes to the side of the bed will easily hold the cloth away from the plants and create a hoop house.
Another important aspect of raised beds is accessibility. People with mobility and flexibility concerns can enjoy gardening in comfort. When beds are just below waist level, the gardener can sit on their edges. This not only reduces back strain, it is an ideal height for gardening from a wheel chair.
When your raised bed is ready, plant seeds according to the package directions or use plants already started. Water the bed well after planting, and fertilize plants throughout the season as you would plants grown in conventional gardens.