RISON – Raised bed gardening has become one of the most popular trends in home gardening over the past few years.
Les Walz, staff chair for the Cleveland County Cooperative Extension Office at Rison, said raised bed gardens have some advantages over conventional gardens because that they don’t require a lot of space, it’s much easier to improve and control the soil, and the beds don’t require as much work once they are completed.
Raised beds are an ideal backyard addition for the backyard homesteader.
Square Foot Gardening
One other factor behind the explosive interest in raised bed gardening is the book Square Foot Gardening by Mel Bartholomew. His philosophy is to raise vegetables in small raised beds filled with a super-charged soil mixture that can nourish several plants in a small space, hence the name “square foot gardening.”
Bartholomew’s concept is based on using 4 foot by 4 foot wood-framed boxes that are 6 to 8 inches deep. The boxes are placed in a sunny area on top of landscape fabric to protect the garden bed from grass, weeds and other vegetation beneath it.
Once the frames for the raised bed boxes are complete, they are then filled with  “Mel’s Mix,” a special soil mixture that Bartholomew promotes in his book.  The recipe is rather simple: 1/3rd compost mixture, 1/3rd peat moss and 1/3rd coarse vermiculite.
The kicker to his recipe is the compost component – Bartholomew recommends the compost contain at least four or five types of compost mixed together. The reason, he contends, is that each type of compost has it owns strengths as far as mineral content is concerned, and by having a variety of composts, the soil will have a better balance of all the minerals needed for most types of plant.
Walz is implementing the Square Foot strategy in the Rison Community Garden, which is located at the Pioneer Village in Rison. While the soil being used in the beds at the community garden is not made using “Mel’s Mixture,” it is a “super soil” that consists of a mixture of top soil and compost.
The community garden started off with 10 raised beds, each measuring 4 foot wide and 8 foot long and 10 inches deep. The bed frames are built from cypress lumber. Another 10 beds will be added to the garden bringing the overall total to 20 beds.
Walz has kept four of the beds to use as “experiment stations” of sorts to test different growing strategies using raised beds.
One experiment Walz currently has underway is growing the same variety of strawberries in raised beds using two different methods: one bed is open to the elements while the other  is covered by a low tunnel. The strawberries were planted late last fall and have survived through single digit temperatures this winter. Walz said the covered strawberries appear to be about a week ahead of the uncovered berries.
Another experiment he just started is growing potatoes in tires. With this method, an old tire is filled with the soil and the potatoes are placed inside. As the potatoes begin to grow, a second tire is added and more soil is added. That process continues until the potatoes are ready to harvest.
Walz is experimenting with different types of soils as well as different placement of the seed potatoes inside the tires. He is using red potatoes and Yukon Gold potatoes in the experiment.
Irrigation Systems

This homemade irrigation system uses 1/2-inch PVC pipe snapped together without glue. A water hose fitting is connected to the trunk line that feeds the “watering” or irrigation lines.

In addition to the crop experiments, Walz is also experimenting with different irrigation systems for raised beds.
Last summer, he installed a do-it-yourself irrigation system built from 3/4-inch PVC pipe. In essence, the system consists of two parts: a trunk line and irrigation or water lines.
The trunk line has a fitting that allows it to be connected to a water hose. The trunk line then supplies water to the irrigation lines, which are simply pieces of PVC pipe with holes drilled in them.
Walz said one of the benefits of building your own system is that you can drill the holes exactly where you want the water to go. For instance, if your plants are 18 inches apart, you can drills the watering holes 18 inches apart so the water goes directly to each plant.
He recommended that the holes be no larger than about 3/8ths of an inch in diameter. The holes should be drilled on both sides of the pipe so one piece of pipe can be placed between two rows to provide irrigation for both sides. Some people drill the holes at a slight angle so the pipe can be turned up for a sprinkler system or turned down for a soaker system.
Walz noted that he does not glue any of the pieces together – they are simply joined together. By leaving them dry fitted, he said the water lines can be easily moved or adjusted.
Another new irrigation system that is being tried this year is a “wicking bed.”  This method works on the same principle as those plant pots that have the water trough attached to the bottom.
Wicking beds are most popular in dry, arid regions of the world where water is a precious resource and they want to get as much use of their water as the can.
The system that is being tried at the Rison Community Garden uses a box frame built from 2×6’s lined with a water proof barrier. That box is then filled with gravel to provide a holding cavity for the water and a piece of PVC pipe with holes drilled in it is placed on top the gravel bed. An an elbow joint is attached to one end of the pipe and another piece of PVC is attached to it. This piece will be pointed up and will protrude through the top of the soil as a means for filling the gravel bed beneath the soil.An overflow outlet is put at the top of the gravel bed to make sure the garden bed is not flooded.
Once the gravel, watering line are overflow outlet are in place, all of it is then covered with a landscape fabric and the garden soil is put on top of that. This barrier is put in place to prevent the bedding soil from washing down and filling the gravel bed.
Tunnel Construction

This “low tunnel” construction method uses 10-foot sticks of 1/2-in PVC arched over a 4-foot wide bed. The sticks are placed over pieces of rebar that have been driven in the ground on both sides of the bed. Once the ribs are in place, 10-foot lengths of 2×4 welded wire fencing were added to keep pests out and support any type of media you would like to put over the bed.

Raised beds are lends themselves as easy-to-construct “low tunnel” systems. This tunnel system can serve as a frame work for a cold frame and/or help protect your crops from pests.
The system being used at the Rison Community Garden uses 10-foot sticks of 1/2-inch PVC that are  arched over and the ends are put on pieces of rebar that have been driven into the ground. The “ribs” of the frame a placed about four feet apart.
For added strength and protection, a 10-foot length of  four-foot 2×4 welded wire fencing is draped over the PVC framework. The ends of the tunnel can then be covered with a plastic bird or animal needing to help keep the deer, rabbits and other pests out of the garden. The welded wire also provides a great support system when a clear plastic barrier is put over the bed for a cold frame or for a shade cloth to raise lettuce, spinach and other shade-loving crops.
The fencing system being used at the Rison Community Garden is not attached directly to the PVC ribs that support it. Instead, a piece of PVC pipe is threaded through the bottom row of fence openings to create a handle of sorts. This process is completed on each side. The handle makes it easy to slide the protective fencing up and down so you can have access to your garden. The handle can then be secured to the ground or the side of the raised bed to make sure it doesn’t blow off.