If I’d known how easy it is to build a raised bed garden plot, I’d have done it years ago instead of having a patchwork, haphazard home kitchen garden.
So, you may ask: Why not just turn over the soil in my backyard? Well, we tried that one, and here’s the thing…
The first spring after we moved into our country home, I decided to plant all of my favorite vegetables and try my hand at gardening. It was the first time I’d ever had my own house with my own dirt to dig in. The front yard was the only option, as our woods come right up behind the house, and there’s not enough sun to grow much of anything back there—except for a lot of moss that grows there naturally. Besides that, we live on the top of a hill on a rocky ledge, where the soil is thin, poor and, well, rocky. That first summer, the only vegetables that grew were quickly eaten by a groundhog. (What is it with groundhogs? They could have any weed or blade of grass in the yard, but they apparently think that fresh veggies are candy, and candy’s better than weeds any day!)
After the first season’s failure, a friend suggested growing things in oversized flowerpots with purchased topsoil, and so for many successive summers, I planted tomatoes and basil this way, plus a variety of herbs. This method was sufficient up to a point, but as time went on, I wanted to grow more vegetables.
And then, two years ago, I had the chance to help a local sustainability organization build a community garden with 25 raised beds. I discovered that even I, who grew up in a family with three boys and never had to wield any kind of tool to build or repair anything—even I could build a raised bed garden plot.
I want to share with you how simple it is.
Basically, you’re going to build a four-sided open wooden box (4 feet x 8 feet x 10 inches tall) and fill it with dirt.
Here’s what you need:
2 pieces rough-cut sawmill hemlock – 8 feet long by 10 inches wide by 2 inches thick
2 pieces rough-cut sawmill hemlock – 4 feet long by 10 inches wide by 2 inches thick
(Note: Our community garden chose hemlock because it’s more resistant to rot and to insects; cedar is also good, but more expensive. Whatever you do, don’t use pressure-treated wood that’s been treated with chemicals.)
Lay out the wood on the ground where you will build your four-sided wooden box, placing the two 8-foot sides opposite each other (four feet apart) and then placing the two 4-foot pieces at either end to form 90-degree angles to complete the box.
12 coarse-thread deck screws – 3.5 inches long
Using a power drill with appropriate screwdriver attachment, use three screws at each corner to connect the pieces of wood. (Presto! You have made a box!)
6 two-foot-long road pins
(A good hardware store will have these; they look a bit like rebar, but they have predrilled holes.) These will anchor the box firmly to the ground and will help keep the sides from bowing out during winter’s freezing and thawing.
Determine where you will place the road pins on the inside of the box, spacing them two feet in from each corner. There will be two along each of the two long sides of the box, and one in the middle of each short side (see diagram). With a sledgehammer or other heavy, sturdy hammer, drive the road pins into the ground on the inside of the box making sure they touch the wood and that the top of the exposed part of the road pin does not stick out above the top of the 10-inch-tall box.
12 small diameter wood screws – 2.5 inches long
Note: The diameter of these must be small enough to fit through the pre-existing holes in the road pins.
Screw three of these through each road pin directly into the hemlock.
1 roll black plastic – 25 feet long x 1.5 feet wide
Line the inside of the box to keep the dirt away from the wood; this will protect the wood from direct contact with the dirt and will increase the longevity of your raised bed.
1 small box of one-inch aluminum roofing nails
Note: These have a nearly one-inch round plastic disc on the head of each nail. Use these to nail the plastic to the inside of the box in this manner: fold about two inches of the plastic over on itself (the double layer will make it stronger) and nail this doubled layer all the way around the inside top lip of the box with the plastic touching all the way to the top (but without sticking over the top) of the box.
Now, you’re ready to buy your topsoil and mix it with compost and other soil amendments.
1+ cubic yards of topsoil and one-half cubic yard of compost
Get out your wheelbarrow and shovel and fill your raised bed; stir in the compost before or after you fill your garden plot—it’s your choice.
A pile of fieldstones
Use these where the ground is uneven, and along the outside of the box, fill any gaps between the bottom of the wooden box and the ground.
Landscaper’s fabric and wood chips
Around the outside of the plot, put black landscaper’s fabric on the grass and cover it with wood chips. Be sure the black fabric goes right up to the wood. The landscaper’s fabric will keep the weeds out of your bed for a couple of years.
And there you have it. You have built your own raised bed garden plot. Buy your seeds; choose your starter plants; and happy gardening.
[The garden construction sketch is courtesy of soil consultant Roger Hill, who can be reached at firstname.lastname@example.org.]