Agriculture Reference
In-Depth Information
will work for a raised bed, just make sure it is untreated. Treated lumber will be the majority of what you'll
find at lumber suppliers because it has many commercial uses. Chemicals are applied to the wood to make it
fire retardant, to slow the natural process of decay, and to prevent termites and other insects from inflicting
damage. Railroad ties, which come in convenient sizes, are generally treated with creosote, another toxic
chemical. These treatments give the wood durability for use in fences, homes, and other buildings—but the
chemicals can leach into the soil (and things growing in that soil), making treated wood a poor choice for ve-
getable garden beds. Don't take chances—ask specifically for untreated wood.
The beds are fairly simple to construct, even for volunteers. Buying the lumber will be a big expense for
your garden, but purchasing in quantity may qualify you for a discount. Also, be sure to tell your supplier
that you are a community garden and ask for any discounts they may offer for all your needed materials.
There are many places to purchase wood, including lumberyards, big-box stores, and local hardware stores.
Shop around and see who will give you the best price. You might also want to negotiate a sponsorship in ex-
change for greatly reduced pricing or even free goods.
Obviously, one of the key factors in building your raised beds is just how big they're going to be. Gener-
ally speaking, 8 feet is a good length. Lumber comes in 8- and 10-foot lengths and can be cut by the lumber
supplier, usually free of charge. Regarding the width of the bed, make sure it is no wider than 4 feet, or 3 feet
if it is going to be situated against a wall or fence. This way the gardeners can reach in comfortably from the
outside without having to step on the soil.
To build a basic wood frame, you'll need four 2-by-6-inch boards, cut to the desired length. If you want
the sides to be higher, you'll work with 8-, 10-, or 12-inch boards. And if you want them to be thicker, that's
fine, too; 2-inch boards are a starting point because they're easy to work with, as well as economical.
Additional materials you'll need include corner posts (standard size is 4 by 4 inches), deck screws (twice
as long as the lumber thickness, to ensure a secure fit; so, for a 2-inch board, use 4-inch screws), and a power
drill. If you wish to deter weeds or are bringing in soil and don't want to have it mix with the garden soil
that's beneath the bed, you will also need a barrier the dimensions of your bed, for the bed to rest on.
If you're using materials other than wood, such as concrete blocks or bricks, the construction process is
straightforward: line them up and stack them straight. Each bed's walls should be at least 6 inches high to
contain the soil and provide enough room for plants to grow. Beds can be built taller, regardless of materi-
als—just be prepared to fill them with more soil. Taller raised beds (24 inches or higher) are a nice perk for
some of the senior gardeners in your community. Their knees will appreciate the thoughtful planning and
kind gesture. Just remember: more soil equals higher cost.
ASSEMBLY INSTRUCTIONS FOR RAISED BEDS
1.
Using a drill bit that's a little smaller in diameter than your screws, pre-drill 2 to 3 holes into the end of
each board (this helps prevent the wood from splitting when you drive in the screws). Have a board or two
underneath the one being drilled to keep the drill bit from hitting the ground when it pokes through the
wood.
