Raised bed gardens
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February
12, 2004
If poor-quality compacted soil, a drainage problem or a physical disability
is preventing you from gardening, then garden beds raised several or more
inches above the natural terrain may be your answer.
Raised bed gardens have several advantages over standard gardens. Plants
that may not naturally thrive in your garden may grow into lush, healthier,
more productive plants when grown in raised beds. Few grasses, weeds and tree
roots interfere with raised gardens. The soil even warms up earlier in the spring
allowing for earlier planting. The physically challenged may prefer to raise
the garden bed to chair height or waist high by constructing tall legs on the
structure. This will enable the person to work completely around the garden
while not having to bend or leave his or her chair. Once the construction of
the bed is completed and it is filled with amended soil or rich compost, the
garden nearly cares for itself with the exception of watering and occasional
weeding.
The first step in planning a raised bed is deciding on its location and
size. I have a garden home where space is limited - and so is the sun. Site
selection and plant selection go hand in hand. So select your site based upon
the right location for the appropriate amount of sun needed by your plants.
While many vegetables and herbs need full sun, many prefer morning sun as
opposed to that of the scorching summer afternoon. Another factor in location
choice is drainage. Good drainage ang proper air circulation are vital to healthy plants. If the bed contains
clay soil, it should be amended with sand, organic matter or a coarse grade of perlite to improve drainage. Consider using a rich compost
such as pecan or mushroom compost, which incorporates organic material needed
for healthy plants.
Selection of the bed materials is the next step. The location of the bed,
its size, and the type of plants will determine the style and materials used in
the bed construction. My bed is not readily seen from my patio area, so I chose
treated lumber, 2 inches thick by 12 inches wide by 8 feet long. The new
non-arsenic lumbers are recommended - alkaline copper quaternary or ACQ, copper
boron azole (CBA) and Tanalith
E. They replace the old CCA arsenic treated lumber phased out by EPA as of
December 2003 for anything with which children might come in contact.
I then marked off the area using my lumber as a guide and sprayed the area
with an herbicide such as Roundup or Grass-B-Gone, diluted according to
directions to kill the Bermuda grass and weeds that had taken over the area.
This step was very important, and I was patient because I knew it would help
deter the constant battle of unwanted grass and weeds in my garden. What
building materials you choose will be determined by the shape, size and purpose
of the garden. It may be elaborate, visually esthetic or very functional.
Landscape timbers, telephone poles, railroad ties, concrete blocks, rocks or
metal edging may also be used.
Construction on the two 4 feet by 8 feet raised beds began when my father
drove from Rockport with the materials loaded on his truck. He pre-drilled and
pre-cut some of the lumber in his workshop from the plan we had designed, and
this made the construction easier. This became a wonderful father-daughter
project that was completed over a weekend and will be enjoyed for years to
come.
Once construction was complete, I lined the bottom with a weed mat material.
Old carpet also works well to prevent the re-growth of weeds and grass.
Choosing the correct soil and its additives are very important. A good quality
loam mixed with compost and manure is an excellent choice. To conserve
watering, I arranged soaker hoses on the beds. I find it easier to plant around
the hoses instead of placing the hoses around the seedlings and plants.
At last, the fun part begins - designing and planting. Since the area is
small, drawing out a planting guide is recommended. I use one of the raised
areas primarily for herbs such as dill, parsley, cilantro, thyme, lavender,
chives, lemon balm, basil, oregano and salad burnet.
During the summer the other bed is planted with tomatoes (
Trellises are terrific space savers in your raised beds. I prefer to build
trellises and tomato cages from bamboo and wooden slats, but other good
materials are PVC, wire and wood. Many garden stores have great selections of
freestanding iron trellises and topiary forms. Even a fold-up laundry drying
rack makes an interesting trellis. Consider decorating a nearby fence with
birdhouses and garden plaques. Be creative with the use of personalized
stepping stones embedded with shells, marbles, leaf imprints, broken tile and
pottery, or even your name.
Mulching with straw, hay, shredded leaves or ground bark helps retain and
conserve moisture. Don't forget to add organic material every season and have
your soil tested every two or three years to determine what nutrients may be
missing. Information about soil testing is available by calling the Victoria
County Extension Office at 361-575-4581. Visit the Victoria Educational Gardens
(VEG) located near the
The Postage Stamp Kitchen Garden Book is a delightful source to use as a
design and planting guide in small spaces. Some themes for raised gardens might
be salad, Italian kitchen, Oriental, Mexican, French, teas, edible flowers or
cut flowers.
Notice the illustration of the construction project for the raised bed that
is currently in my yard. Following the illustration is a list of supplies and
directions for constructing one 4 feet by 8 feet bed. The best part is enjoying
the finished product, and you will never have to till again. Gardening has
never been simpler. No more aching back. See you in the garden.
*Three 2x12 8-footers (Cut one in half for end pieces)
*One 4x4 8-footer (Cut into four equal pieces, approximately 2 feet long to
be used for corner reinforcements)
*Two 2x4 2-footers for side reinforcements
*Twelve 3/8x6 galvanized bolts with nuts
*Four 3/8x5 galvanized bolts with nuts
*Thirty-two 3/8-inch flat galvanized washers
Drill two 3/8-inch holes in each end of the 2x12s and through the 2-foot
long pieces of 4x4s for reinforcement. Bolt together with 6-inch bolts
and washers. One foot of each 4x4 reinforcement posts will protrude into
the earth for stability.
Bolt the 2-foot pieces of 2x4s midpoint of the 2x12s with 5-inch bolts and
washers so 1 foot of each will protrude into the earth to keep the sides
stable.
Dig six holes in the earth to accommodate the 1-foot long reinforcements.
The 2x12 8-foot frame will sit on the earth ready to be filled with soil,
sand and organic material.
For further reading on Raised Bed Gardening consult any of the following:
· Murphy,
W.B., J
Newcomb, Duane and Karen. "The
Postage Stamp Kitchen Garden Book." Adams Media
Corp.,
Sperry, N. 1991. "Neil Sperry's Guide to
Complete
Wasowski S. and A. Wasowski. 11997. "
Texas A&M University System Extension Publications on the Web at: http://tcebookstore.org/ http://www.diynet.com/diy/fv_planting_harvesting/article/0,2029,DIY_13828_2269848,00.html