BY LORI MURRAY
Raised bed gardening is an effective method of gardening here in the Lower Rio Grande Valley where we have heavy clay soil. Raised beds allow us to create a better soil – one that drains well and contains the nutrients healthy plants need. And raised beds allow us to tailor the bed to our needs – large, small, high, low, and so on. In the same way, it allows us to have only one bed, or several, and of varying sizes.
Basically, a raised bed is simply a box with no top or bottom – just four sides. It sits on top of level ground (or pavement, if necessary) and can be made of wood (cedar or redwood is best because soft wood tends to rot), concrete blocks, bricks, or even stones. It’s best not to use treated lumber but synthetic lumber made of recycled plastic works well. Even horse troughs can be used, so long as there are drainage holes in the bottom.
If you are building a raised bed, it can be square or rectangular but should be no more than three or four feet wide for ease in weeding. It should have a depth between six and twelve inches to accommodate root growth.
A bed liner is a handy addition because it keeps soil from getting washed out of the bed during heavy rains, but remember that it must be porous and promote drainage or you will drown the roots of your plants. The corners should be secured in some way. One method is to drill into the two pieces at each corner using spikes. Another is to use purchased corners.
Also, eight PVC pipes or stakes can be driven into the ground at the corners and outside the bed to secure the bed and its contents in place. If you cut the stakes twice (or a little more) as long as the bed is high, you can bury half the stake in the ground and use the protruding piece to secure a cover you might need in case of especially cold Valley weather.
Use a good, loose soil with compost, or use a combination of equal parts peat moss, compost, and perlite. Mix the combination thoroughly.
Mel Bartholomew, a retired efficiency expert who authored Square Foot Gardening suggests physically dividing the box into square feet (what else?) by tacking 1×2’s across the length and width, making the overview resemble a piece of graph paper.
One plant is grown in each square foot section. Some gardening catalogs offer ready-to-assemble grids made of wire. When it’s time to replant the square, just add another tablespoon or two of compost and mix it in well to loosen the soil.
Leftover vegetable plants can be mixed right into the soil and allowed to decompose (Just like Grandma used to do). Drip lines or soaker hoses can be run on top of the bed for easier watering and because the wet foliage caused by overhead sprinkling may become susceptible to disease. Or you can simply let the hose run slowly in the bed itself.
Gardening suppliers offer raised bed kits, sides, corners, and liners at anything from reasonable to exorbitant prices. Simply go online to find them. And start small until you can experience how the process works without wearing the fun out of growing your own flowers and/or vegetables successfully.
Sources: University of Missouri Extension; Square Foot Gardening by Mel Bartholomew
A one-hour Rainwater Harvesting Workshop will be offered on Wednesday, March 22nd from 11 a.m. to noon in the meeting room of the Cameron County Extension Office. Master Gardener Edgar Claus will present harvesting methods and provide hands-on instructions for assembling the take-home rain barrel included in the $50 fee.
The office is located at 1390 West Expressway 83 in San Benito, next to San Benito High School. Pre-register by either emailing firstname.lastname@example.org or calling 956.361.8236.