Creating a Raised Bed Garden
Our columnist Kevin Lee Jacobs shows us how to build a raised bed garden and explains why it's easy to grow vegetables, flowers, and herbs in these convenient elevated beds.
Raised Bed Gardening
If the idea of growing a year’s supply of healthy, organic vegetables and herbs appeals to you, but the thought of digging through compacted, rocky soil does not, consider growing your crops as I do: in raised beds. You’d be amazed at how many benefits there are to gardening “on higher ground,” and how easily beds can be constructed.
Kevin Lee Jacobs blogs at A Garden for the House. He was introduced to gardening when he was no taller than a delphinium. Today, his home in upstate New York features formal rose gardens outdoors and lavish window gardens indoors.
What You'll Need
You can build a raised bed from almost any material you like, as long as it is sturdy and does not contain harmful chemicals. Do not use pressure-treated lumber (including railroad ties) because it contains toxins that can leach into the soil. Bricks, cement blocks, and untreated lumber are all suitable for framing.
Even cheap pine boards can be used to frame a bed. Pine, however, is not rot-resistant, so you’ll have to replace it after four years or so. The boards will last longer if you first paint them with raw, not boiled, linseed oil. I used untreated 1-by-10 inch pine for the beds in my herb garden. After one season the wood turned from boring beige to graceful gray. I paved the paths between beds with pea gravel, and then enclosed the entire garden with wire mesh attached to pressure-treated posts.
Kitchen Gardening in a Raised Bed
For my kitchen garden, I built eight 4-by-8 foot beds from inexpensive, rough-hewn hemlock. Hemlock, like cedar and redwood (these last two are pricey) is naturally rot-resistant. The boards of these beds are 12-inches high and 2-inches thick. Running perpendicular to the hemlock-enclosed beds are four 2-by-8 foot beds framed with 1-by-10 inch pine. Paths here are paved with shredded wood chips, and the garden is protected from woodchucks, rabbits, and deer by wire-mesh fencing.
Learn more about gardening in raised beds.
How to Build It
As for building a timber-framed bed, no carpentry job could be easier. Simply join the corners together with galvanized nails or screws. I used 1 ½-inch nails for my thin pine-framed beds, and 4-inch screws for my thicker hemlock models. Although corner posts are commonly used for raised beds, I have not found them necessary.
Before filling a frame with soil, it is imperative to line the bottom of the bed with either corrugated cardboard or several thicknesses of newspaper. This material will smother any weeds or grass that would otherwise grow up through the raised bed and that would impede your perfect planting plan.
Flowers in Raised Beds
Of course, flowers love raised beds as much as vegetables do. I always plant zinnias in the long central beds of my kitchen garden; they attract the bees and butterflies necessary for pollinating my crops and provide beautiful bouquets for indoor enjoyment.
Raised bed gardens mean that you get to garden in perfect soil. By “perfect,” I mean soil which is fertile, well-draining, and free of rocks and weeds. My own veggies flourish in equal parts top soil, composted manure, and sand. These components were mixed and delivered by a local farm. I’ve known other gardeners who fill their beds with packaged mixtures obtained from the garden center or hardware store.
To insure ongoing fertility from year to year, and to avoid the need to purchase additional soil to refill the beds as settling occurs, I top my beds off each fall with shredded leaves. As the leaves decompose over winter, they add vital nutrients to the soil, and improve its water-retention.
Soil in a raised bed does not become compacted. Why? Because it is never walked upon. Unencumbered by hard clumps of soil or rocks, root vegetables like carrots and parsnips grow straight and long; beets and turnips grow into the beautiful globes depicted on their seed packets.
If you suffer from a bad back, you will appreciate being able to plant and harvest your vegetables without bending deeply. In fact, if you build your beds high enough, you won’t have to bend at all. If you limit your beds to 3 to 4 feet in width, you will not have to reach excessively, either.
Less Work, Higher Yield
Because plants can be grown very close to each other in a raised bed, even a tiny yard can support a lavish edible garden. The four 6-by-4 foot beds in my small herb garden, pictured here, produce copious quantities of parsley, thyme, and other aromatics. I pick these herbs at the peak of their perfection, then freeze them for winter use.
A raised bed vegetable garden has less weeding, less bending, and absolutely no tilling—there are really no negatives to this type of gardening. I hope you’ll consider gardening above ground, too.