How To Make Raised Planter Beds With Composite Wood

Prepare the Bed

• 1

  Select a site. Considering the expense and longevity of the material, select it carefully. Look for sun exposure through the growing season; the ideal site should get at least six hours of sunlight a day. It should have a dimension of 4 feet-by-8 feet, with a lengthwise orientation of north/south to receive even sun exposure.

• 2

  Measure an area 44.5-by-92.5-inches; this will be the interior bed within the structure. Mark it with stakes and twine. With a shovel, remove all vegetation within the twine. Discard or compost.

• 3

  Place a tarp beside the rectangle. To a shovel-blade length, dig all the material from the rectangle onto the tarp. Keeping the walls straight and the floor of the hole level, dig a second level down. You should have a rectangular hole approximately 22 inches deep. Check with a level and readjust as needed.

• 4

  With the shovel, thoroughly mix the extracted soil, 1 cubic yard peat moss, 1 cubic yard compost and 1 cubic yard sand or coarse perlite.

Build the Structure

• 5

  With a 1/2-inch drill bit, drill centered holes 4 inches from one end of a 4-by-4-inch, 4-foot-long wood-plastic composite post. Drill centered holes 7 1/2 inches from the end of each post. You will do this on a total of 18 posts.

• 6

  Place the posts horizontally in an overlapping herringbone pattern around the rectangle. Line up the holes you drilled in each post. (See the illustration in reference three from University of Missouri.)

• 7

  Fill the bed with the soil mix to the top of the structure. Hammer a 3-foot piece of 1/2-inch diameter through each of the holes. Keep the rebar straight so it doesn't intrude into the bed.

• 8

  Contour the top of the bed with the rake.