Would you like to have more garden space with less stooping? How about spending less time doing soil preparation? Or maybe you would just like to have a little hardscaping for visual interest but you don’t want to invest a lot of time and money into construction. Raised bed gardening may be just the thing for you.
Raised bed gardening involves building frames that can range in height from six inches to 18 inches and filling the frame with good garden soil. Frames can be any length, but most people prefer beds that are four to six feet long, or the length of a standard piece of lumber available at the hardware store.
Raised beds provide a number of benefits. Building a raised bed “pyramid” creates visual interest and increases the square footage available for planting. Second, raised beds can extend the growing season. Soil in raised beds warms quickly, and the bed can be covered with a hoop or tunnel to protect plants when frost threatens in early spring or late fall. Third, raising the level of the soil minimizes the need for bending or kneeling.
This makes planting, weeding and harvesting more convenient for individuals with mobility challenges. Fourth, watering and irrigating raised beds is easier and less wasteful than attempting to water the average garden area. Some raised bed kits come with a drip irrigation system or a sprinkler head fitted to the bed.
Finally, the soil in raised beds can be blended to a gardener’s specifications. One raised bed can be filled with compost-rich humus for squash, melons or salad greens, while another can be filled with sandy humus that is ideal for carrots and other root vegetables. Raised beds increase possibilities for gardeners.
The big question, of course, is how difficult is it to build one – or several – raised beds? The answer is that raised beds are very easy to construct, even for someone for whom DIY is a four-letter word.
Die-hard do it yourselfers can build their raised beds with paver bricks, flat stones or standard 2 x 4s in whatever lengths are desired. The easiest to assemble is a basic “box” made of lumber that would be appropriate for decking; don’t use treated wood, however, because the chemicals used to treat the wood can leach into soil and contaminate edible crops.
The depth of the box should be a minimum of 6 inches. Lumber can be stained and sealed or left unfinished. Staining and sealing will extend the life of the fixtures and help keep them weatherproof.
These structures will be permanent fixtures in the landscape, so take care that the construction be aesthetically pleasing as well as functional.
A much easier – and temporary – solution is to purchase a raised bed kit. These kits generally contain artificial lumber boards, corner brackets and anchors for the larger sizes. The brackets are on a stake with a pointed end that slides into the ground and openings that hold the lumber.
Many of these kits are stackable, creating a significant amount of growing space but using a minimal amount of square footage. These beds assemble and disassemble quickly. Most people break these beds down at the end of every season and store the pieces in a shed or garage.
However the beds are constructed, they need to be filled with soil. This is where the fun begins, because a gardener can create growing conditions in raised beds that would not normally be found in their location. For example, a bed in which herbs are to grow would require a sandy loam that drains easily.
Midwesterners can grow hardy cacti in a soil mix that is primarily sharp sand. A standard kitchen garden or vegetable bed would need a rich loam; squash, cucumbers and pumpkins need extra manure or mushroom compost added to the soil mix for optimum fertility.
Once the soil has been installed, the beds can either be direct seeded or starter plants can be placed into them. Once the plants are placed or the seedlings have emerged, then it’s time to mulch. Raised beds drain more quickly than flat beds, so mulch helps to keep the soil evenly moist during the growing season and it also helps keep weeds to a minimum.
The kind of mulch you use depends on the plants in the bed. Tomatoes, for example, benefit from either black or red plastic mulch. Leafy greens or herbs benefit from wood chips or shredded bark, which keep soil cool during hot summers and also keep soil from splashing up onto leaves that will be going into the evening’s salad.
Bed maintenance consists of ensuring the bed is adequately watered, and applying time released fertilizer around plants at the beginning of the growing season, or applying a water-soluble fertilizer once a week. The water-soluble fertilizer can be applied with a watering can, sprayer, with a sprinkler that is focused strictly on the bed or through drip irrigation. \
Because the garden area is contained, less fertilizer can be used throughout the season, as there will be less runoff and waste. Near the end of the season, the beds can be covered with clear plastic tunnels in order to stave off frost damage and extend the growing season. Gardens built in areas of extreme heat (Texas and Arizona come to mind) can be covered with shade cloth during the warmest time of the day to prevent sun scald.
Raised bed gardening affords greater accessibility for motion-challenged individuals, creates opportunities for more plant diversity, and helps extend the growing season. Raise the standard on your garden this year and try a few raised beds.