Raised Bed Gardens
Raised beds are the perfect solution to heavy clay soil – the beds drain well, are easy to maintain evenly during and after irrigation, and there is less crusting of the soil if properly prepared.
Incorporate organic matter
Spread a two or three inch layer of organic matter over the soil surface. Coarse material such as twigs, leaves, straw, and well-rotted manure make excellent composts.
Six or seven cubic yards of compost are needed to cover a one thousand square foot garden with two to three inches of compost. As organic matter breaks down, additional nitrogen will be needed. Add enough nitrogen to the organic matter to aid decomposition process. To decompose a thousand square feet of organic matter two to three inches deep, use about twenty pounds of ammonium sulfate, twelve pounds of ammonium nitrate or nine pounds of urea. This fertilizer will aid in replenishing soil nutrients, but is not intended to aid in plant growth. Add a complete fertilizer at the recommended rate when planting seeds and transplants.
After spreading the material over the organic matter, work the soil about six inches deep. Using a spade or fork turn the soil and mix in the organic matter, but extra care is needed to break up clods sufficiently. A tiller makes a smooth, soft surface with the least difficulty.
Use a shovel to dig a trench or walkway about six inches deep. This removes all the soft soil to create a shovel width walkway. Pile the loose soil onto the bed. Make the next walkway about 48 inches from the first.
Rake the beds flat on top. The natural slope at the edge of the beds will leave a bed about 36 inches wide. Adjust the width as needed. The finished growing bed will include about eight inches of soft prepared soil for plants to grow in. Walking, kneeling, or sitting on the beds will compact the soil and stunt plant growth – always work from the walkway areas.
Put a layer of organic matter on the bottom of the walkways to prevent problems with mud. Permanent raised bed gardens may have lawn planted down the walkways to keep weeds under control and provide a nicer place to work from. Beds may also be lined with railroad ties.
Once the beds have been prepared, it is now time to plant the seeds or transplants in the beds. Make the beds a foot wider for double rows of larger plants such as tomatoes. Plant vine crops such as squash, melons and cucumbers in a single row down the middle of the beds so they have room to spread over the edges. Very large plants such as Hubbard Squash may need wider beds to allow extra space for growth.
The 36-inch beds are wide enough for wide-row planting. Smaller plants like carrots, beans, and lettuce can be planted in wide rows. Spread the seed evenly across the top of the bed and cover properly. As the seeds grow, they will shade out emerging weed seeds – reducing the need for weeding.
Raised beds with organic matter tend to dry out faster than clay soil. The loose nature of the soil also means it will absorb water faster. Soaker hoses, drip systems, or sprinklers provide excellent watering methods in these gardens. Keep walkways as dry as possible to help control weeds.
Compost the soil to maintain even moisture adding more leaves, grass clippings, etc. as the earlier layers decompose and disappear. A thick layer of leaves or other organic matter in the trenches will compost over the season and can be raked onto the beds later. A layer of leaves or organic matter put over the beds in the fall will decompose and can be tilled into the soil the following spring.
Plastic mulches are exceptionally well adapted to wide-row raised bed planting. Place two soaker hoses down the beds, with one hose on each side. Cover the beds with plastic – cut holes in the plastic to plant transplants or seeds.