Recently, I conducted an Internet search for raised planter bed kits in order to compare commercially available prefabricated ready-to-assemble beds with Noble Foundation-designed beds. My search turned up eight different kits. The primary materials used in most of the kits are cedar and recycled plastic. One manufacturer uses aluminum sheeting. The one thing all the kits have in common is a high price tag, ranging from $3.50/square foot to $16.50/sq. ft. As would be expected, the more expensive kits come equipped with beautiful cedar planks, which, when assembled, form beds high enough to use while seated. The least expensive kits form 6-inch-high beds and are generally made from recycled plastic boards. While these kits offer an attractive and relatively hassle-free way of constructing a raised bed garden, they are not a viable option for the cost-conscious gardener.
At the Noble Foundation, we've researched and demonstrated the benefits of using permanent raised beds in both commercial and hobby gardening. Our search for an inexpensive, durable material to use in raised bed construction led to the development of rubber lumber made from recycled automobile tires. Introduced in 1995, rubber lumber continues to be the material of choice for constructing no-frills permanent raised bed gardens. Individuals having access to a few power hand tools and not afraid of hard work can construct rubber lumber raised beds for as little as $0.20/sq. ft.
One limitation of the rubber lumber bed is that at 8 inches high, it is too low to work while in a seated position. Consequently, recent efforts have focused on the development of a relatively inexpensive high-profile raised bed.
After evaluating several materials and construction techniques, we settled on a corrugated sheet metal-lined bed supported by a frame made of sucker rod and 2-inch by 4-inch treated lumber.
As with any "homemade"bed, components of the Noble Foundation corrugated sheet metal bed will need to be prepared using power hand tools prior to assembly. Considering that the cost of our corrugated sheet metal bed is only one-fifth ($1.36/sq. ft.) the cost of a similar size ready-to-assemble bed, the required preparation time is well worth it.
Of all the different high-profile bed designs we've evaluated, the corrugated sheet metal design is the easiest and quickest to construct. Plans for constructing a 40-inch wide by 30-foot long by 14-inch high corrugated sheet metal bed, designed with your back in mind, can be obtained by calling the Foundation at (580) 224-6500.