Raised beds make your backyard a garden

Published 12:58 am Sunday, March 29, 2009

Many are taking advantage of the warmer temperatures we’ve enjoyed recently and are starting to break ground in preparation for this year’s vegetable garden. I have not had a chance to work up any ground yet but I have put together my list of vegetable plants to include in the garden this year. Often time people think that you have to have a large amount of land and heavy duty equipment to have a vegetable garden. At the very least you have to have a tiller, right? Wrong! You can grow and enjoy vegetables from your own backyard even if you don’t have a tiller. Raised beds are a wonderful way to enjoy gardening in your own backyard if you don’t have the equipment or space for a “traditional” garden. A raised bed doesn’t have to be fancy or expensive either. Raised bed gardens offer many advantages over conventional in-ground gardens. Soil in raised bed gardens warms up quicker in spring often allowing for earlier planting dates. These gardens are generally filled with high-quality soil which greatly improves drainage and increases crop yields. Raised beds are smaller than traditional gardens which make them easier to maintain. As with anything in life there are disadvantages as well. Raised bed gardens do not typically hold water as well as traditional gardens and may require more frequent watering during dry months. They can also be more expensive to establish initially.

In Alabama a soil depth of at least 10 inches in a raised bed garden is recommended. Raised beds are generally constructed using a frame of some sort to hold the soil in. The frame should be at least 1 foot tall so that the soil inside can be 10 inches deep and not reach the top of the frame. If the soil is at the same level as the sides it may wash out when water is added. There are countless materials that can be used to frame the raised bed. For instance, many gardeners use cinder blocks, bricks, rocks, tires, treated lumber, old railroad ties (never new), etc. There is no rule that says you have to go out and buy new materials so if you can make use something that you have around the house then by all means do! I often get questions about use of treated lumber in raised bed gardens. The most common wood preservative traditionally used was chromated copper arsenate (CCA) which was phased out on December 31, 2003, for virtually all residential use including raised beds. Two other products, ACZA (ammoniacal copper zinc arsenate) and ACQ (ammoniacal copper quat) have replaced CCA and may be used for raised bed construction. Well-documented research has shown that CCA, ACZA and ACQ may be safely used to construct vegetable beds. Some gardeners still prefer to line the sides of beds with polyethylene plastic so that roots do not come into contact with the material. Make sure you do not use plastic on the bottom of the beds as this will prevent water drainage.

Raised beds can be made to any desired size but a width of no more than 4 feet is recommended. The average person can reach 2 feet so a 4 foot wide garden can be comfortably worked from both sides. Vegetables require full sun and water so make sure you locate your garden in a sunny area near water.

One of the greatest advantages of a raised bed garden is the ability to amend the soil. A good mix contains equal parts topsoil and organic material. This will create a soil that drains well and is easy to plant in. Soil pH and fertilization requirements are the same in both raised bed gardens and traditional gardens. To determine your soil’s pH and fertility needs, you can pick up a soil test box at the Chilton County Extension Office.

When planting in a raised bed it is important not to over-crowd plants. A crowded garden is going to be more likely to have disease problems than one where plants are properly spaced. The required amount of space depends on the crop being grown. For example: tomatoes and squash should be 24-30 inches apart; cucumbers can be grown on vertical trellises in raised beds and should be planted 18 inches apart; corn, okra, and potatoes need to be 12 inches apart; and southern peas should be planted 6 inches apart. For more information see www.aces.edu/pubs/docs/A/ANR-0479/ANR-0479.pdf or call 1-877-252-4769 (select ext. 3).