Raised bed gardening is a versatile method of gardening that incorporates a tidy look with fertile soil and productive plants. Raised beds can produce twice as many vegetables as traditional gardening methods in the same space. Using the most efficient planting methods makes this possible.
Raised beds are typically planted with closer plant spacing than a traditional open garden, so every inch of space should be planted. A good plan will make a raised bed more productive, as well as save money on your garden budget. Locate your raised beds in areas of your yard where they will have the correct conditions for the plants you want to grow. Light is one consideration, and drainage, air flow, and foot traffic around the bed are some other things to think about. Locate a raised bed in front of a southern wall, and the reflective heat can warm up the raised bed early in the season, so it can be planted earlier.
Popular planting methods for raised beds use grid systems to make the most efficient use of the planting space. Temporarily lay string lightly across the soil surface to mark divisions in the raised bed, and decide how densely your plants can be spaced within the divisions. Marking the sections with string helps keep the seeds or transplants organized and properly spaced according to your plan. For example, if you allot one square-foot section of a bed to a tomato plant, the square foot adjoining it might be planted with 144 baby carrot seeds set in a 12-by-12 grid. If you use the section method of planting, every inch of your raised bed can be planted.
Root crops produce best if they have deep, fertile soil. Double digging is a method of soil improvement that increases the depth of good, fertile soil. Whether you are establishing a new raised bed or reviving an old one, loosen and remove the soil from the bed area to a depth of 8 to 12 inches. Fill the resulting hole with a blend of compost and original soil. Mix more compost with the remaining original soil and use it to fill the planting bed. The top layer of soil should have a higher concentration of compost and organic matter, because it will break down more quickly, right in the root zone. This method instantly improves the deep soil in your raised bed, and it is an excellent way to prepare a raised bed to plant root crops.
Plant root crop seeds close together, spacing them to allow for the average mature size of the root between seeds. If you harvest beets when they are 2 inches in diameter, you should plant the beet seeds 2 inches apart in a grid pattern; radishes might be planted on a 1-inch grid pattern.
The limited horizontal space in a raised bed makes the use of vertical space appealing. Tall plants will use a minimum of ground area within the bed, and they will fill a vertical area with produce. Vertical plants are those that require stakes or a trellis, such as pole beans. Pole beans require about 1 foot of row width space and grow vertically, as compared to bush beans, which require a 2 to 3 foot wide row space to sprawl.
Use clear plastic sheeting to cover your raised beds in the early spring. This creates a cold-frame atmosphere for seedlings that need to be hardened off before they are transplanted to their permanent location. Entire beds of lettuces, spinach, and other cool weather crops can be started extra early if they have the protection of a covered raised bed. The same type of cover can be used in the fall to prolong the growing season by protecting late garden plants from frost and early freezing.