Start a Community Garden

Raised Bed

Purpose

Why do we use raised beds for growing vegetables? There are two reasons. The first being in the greater Houston are most of our soil is clay gumbo which is not conducive to growing vegetables due to lack of nutrition and compaction issues. The second and equally important reason is rainfall. It is not uncommon for the Houston area to get several inches of rain in a very short period. By raising the height our vegetables stand a better chance of surviving our rain events. Most plants prefer not to have their roots in standing water for any length of time and plants in standing water can die in a surprisingly short period of time (hours)

Raised Bed Frames

Frames are needed to contain the new soil and keep it from washing away, to keep weeds out, and keep water from running off.

Requirements

• Durable frame sides to keep the bed flat and raised 8 inches.
• Frame height from 4 in. to 3 ft. or more.
  a)You need at least 4 in. to assure minimum drainage and provide enough loose soil to weed, and 6 in. to grow the shortest carrots.
  b)We recommend an 8 in. bed. This height minimizes weed invasion and is the most cost efficient.
  c)Productive sweet potatoes need at least 1 ft. of depth. (An 8 in. bed can be temporarily altered by mounding soil in the center of the bed.)
  d)High drainage plants such as thyme and Irish potatoes prefer to be raised at least 18 in.
  e)For persons needing to sit high while working, such as wheel chair gardeners, 24 to 36 in. is optimum.

Materials

• Frames can be made from a variety of materials, each with their advantages and disadvantages. Frames must be durable, rot-resistant, attractive, easily obtainable, inexpensive, able to hold soil, easy to weed, and non-toxic.
  a)We recommend 8 x 8 x 8 in. hollow concrete blocks or 4 x 8 x 16 in. solid concrete shim blocks. Blocks are reasonably attractive, make weeding easy and permit removal for redesign. They last indefinitely and provide a convenient means for spacing plants inside the bed. Beneficial toads and ground beetles all like being around them.
  b)The 8x8x8 in blocks are easty to sit on to rest or visit. Concrete blocks have no major disadvantages except for cost and transport weight..
  c)Order the blocks at least a week in advance and have them delivered a few days before the garden will be built. You will also need a claw hammer or crowbar to remove the steel bands that keep the blocks on the pallet. The blocks will be delivered to the nearest accessible pavement. If this is a long way from the garden, you might consider renting equipment to move the blocks.
  
• If you can't afford concrete blocks, we suggest inexpensive pine or recycled boards with reinforcing stakes on the outside.
• We do not recommend cedar, plastic or metal.
  a)Cedar costs nearly as much as concrete and is much less durable.
  b)Plastic deteriorates rapidly and while plastic wood is stable, it is more costly than concrete blocks.
  c)Metal flashing is one of several other possible frames if the garden is in a remote place or very large.
  d)Timbers are less durable than concrete blocks and cost the same per inch of height.