Sometimes garden writers make things involve more work and expense than necessary. Raised garden beds are one example. Your crops will grow fine whether your beds are level, raised or even sunken (a good choice in dry, windy regions).
Maintaining dedicated beds — where you plant crops — and dedicated pathways where you walk is the important piece.
Compacted soil is the enemy of strong plant growth. The more easily a plant can send roots into the soil, the faster the plant can absorb the nutrients it needs and the more drought-resistant it becomes. If the plant has to spend energy pushing roots into hardened soil, the plant has less energy to grow and produce well.
In nature, meadow mice, moles, earthworms and other critters tunnel throughout the soil — and thus counteract compaction — and humans and other large critters do not walk over the soil often. But in a garden, we walk back and forth a great deal, and our footsteps definitely compact the soil. “One winter, we took a shortcut across a fallow field, using the path almost daily,” reports market gardener Anthony Boutard in his splendid book, Beautiful Corn. “When I looked at an aerial photograph taken three years later, I could still see that pathway reflected in the reduced growth of the crop planted there.”
The best way to minimize soil compaction is to lay out defined areas for growing and defined areas for walking. First, measure the entire area and make a drawing on paper (or use our nifty Garden Planner software). Choose a bed width that lets you easily reach to its center from the path. Think about where you want composting areas, where you will want gates if you fence the garden, and where to leave room for a worktable or two and a bench with a nice view.
You can make paths as narrow as 1 foot if your space is limited, but always make a few main paths wide enough to accommodate a garden cart or wheelbarrow comfortably. If your garden area slopes, arrange the permanent garden beds across the slope rather than down it to minimize erosion. Build most of your beds the same size so you can use row covers, critter protectors and chicken tunnels interchangeably. Use wooden stakes, pipes or rebar to mark the corners of the beds. The stakes can do double duty as hose guides — simply slip a length of plastic pipe loosely over each, and hoses will slide around them easily.
Growing vegetables in garden beds is far more efficient than maintaining single rows of crops. From the paths on either side of a bed, you can easily weed and harvest crops in a bed 3 to 4 feet wide. When you plant several rows next to each other in a wide, permanent bed without a pathway between them, crops grow together to shade the soil and thus reduce weeds. But if you placed pathways on either side of single rows, you would compact more of your garden soil as well as leave more area open to sunlight, which permits weed growth. Permanent beds and paths also let you apply fertilizer and water more efficiently.
We hear a lot of talk about “raised bed gardening,” but unless your site has drainage problems, there’s really no reason for garden beds to be raised. In fact, choosing raised beds may have as many cons as pros (read more about "Raised Garden Beds: Pros and Cons" later in this article). Feel free to skip raised beds and just go for the cheap garden beds. You’ll be glad you did.
6 Ways to Get a Cheap Garden Bed Growing
Here are half a dozen methods for creating garden beds from scratch while easily incorporating what we see as the most important tenet of building new beds: keeping your planting areas separate from your walking areas.
Instant Gardens. For areas that are currently in grass or weeds, one of the simplest ways to create new beds without any tilling is to use bags of topsoil laid out to cover your bed areas, with sheets of cardboard or newspapers covering the pathways. Cut out the tops of the bags, use a long knife to punch drainage holes in the bottoms, and you’re ready to plant smaller crops, such as lettuce, bush beans and basil. Use grass clippings or straw to conceal the edges of the bags and the cardboarded paths — then go get the garden hose! Over the summer, the bags and mulches will kill all of the grass and weeds. You won’t need to do any digging until the end of the season, when you can gradually remove the plastic bags and work the topsoil into your native soil. (For more about these “instant beds,” read How to Make Instant No-dig Garden Beds.) Instant beds probably won’t give you a harvest as good as other methods we cover here, but the advantage is the ability to create new beds quickly, with no initial tilling.
Lasagna Gardens. If you have access to a good supply of grass clippings, fall leaves, straw or hay, you can start “lasagna” garden beds. Stake out your beds and pathways, lay cardboard down in the pathways, and then mulch the beds heavily with layers of whatever organic materials you have to smother the grass. If you use the lasagna technique in fall, the beds will be ready to plant in spring. Set transplants into the soil under the still-decomposing layers of mulch. To sow seeds, you’ll need to spread soil over the mulch, or dig to mix the thick mulch (which is slowly turning to compost) with the native soil.
Till and Rake. Bagged topsoil isn’t cheap, and sometimes it isn’t even as good as your native soil. Another less expensive way to convert lawn into garden — without buying soil — is to use a tiller to kill the grass. If you don’t own a tiller, you can rent one or — perhaps even better — hire someone to till the area thoroughly for you. (Tilling sod is best done with a large tiller — check local classified ads or Craigslist to find someone who offers this service.) After the area has been tilled, use a garden rake (not a leaf rake) to go over the area thoroughly and remove clumps of grass and roots to the compost pile. If your soil has lots of small rocks, you may want to invest in a rock rake from Lee Valley Tools or the Radius Garden Shark rake. Next, use stakes to mark out where you want each bed and pathway. Rake loosened soil from the pathways into the bed areas, and you’ll have tidy, slightly raised beds without having to spend money to bring in soil.
Buy Some Soil. If your native soil is poor, you may decide to hire a landscaping company to bring in a load of soil to spread out where you want permanent garden beds. If you go this route, choose a reputable company, ask for a product that includes compost blended with the soil, and verify that the company guarantees the mix is free of noxious weeds (especially nutsedge and morning glory) and herbicide residues. If possible, till the growing beds before you spread the soil.
Turn With a Spade. This method is probably the best because it loosens the soil deeply, but it requires more physical work than other methods. Mark out the garden beds and pathways, and then use a good spade to cut and turn the sod in the bed areas. Take your time, digging maybe one bed per day. Pave the pathways with cardboard or newspaper, covered with grass clippings or other mulch. If you can, apply several inches of compost or mix a good layer of grass clippings into the beds. Rake them smooth, and you’re ready to sow seeds or set out transplants.
Chickens in the Garden. If you have chickens and a portable coop (see our most recent portable coop plan in Build This Predator-Proof, Portable Chicken Coop for Your Backyard), the birds can do a nice job of killing sod and scratching up the top few inches of soil in new or existing beds. They also add manure to the soil. (For more on gardening with chickens, read Chickens in the Garden: Eggs, Meat, Chicken Manure Fertilizer and More.)
Depending on how much time and money you have, you can combine these six techniques. For instance, turn a few beds with a spade the first year and build the rest of the permanent garden beds using topsoil bags or lasagna layers. Then, after the season has ended, you can dig the remaining beds deeply as you have time, or move chickens onto them to add fertility and eat weed seeds.
The Essential Broadfork
I recommend that you eventually buy a broadfork so you can loosen the soil before planting each crop. A spade or garden fork will work, but a broadfork will do the job faster and more deeply. I’ve found that broadforks made entirely of metal are more rigid and work better than those with wooden handles. (I especially like the Vashon broadfork from Meadow Creature.) With a broadfork, you work the long tines into the soil and then pull the handles back so that the tines lift the soil to loosen it without actually turning it over. That way, the soil is aerated for better root growth and faster warming in spring. By not turning over or mixing the soil (as happens when gardens are plowed or tilled), you’ve minimized disruption to the layers of soil-dwelling critters that create fertility.
Should Beds Be Framed?
Framing is strictly optional. Frames can make your garden look tidier and provide locations to attach hoops for mini-greenhouses and row covers, but depending on the framing materials you choose, this can add significantly to your startup costs. New lumber is pricey, and most boards will begin to rot after a few years. (If you do choose to make board frames, 2-by-4s will work just as well as more expensive 2-by-6s and will require less soil to fill.)
Rather than buying lumber, look for low- or no-cost frames. For instance, my neighbor gave me a load of cedar fence rails he was replacing, and they have made perfect frames for my beds. I simply raked tilled soil from pathways into low raised beds and laid the cedar rails down on the long sides of each (see a photo in the Image Gallery). Even with no end pieces, the fence rails stay right where I put them, and I can easily adjust a bed’s width if need be. Fencing companies replace rail fences constantly and would probably be happy to have you take used rails off their hands.
Four- to 5-inch-diameter logs also work well as frames — not on the ends, but just laid on the long sides of the beds. Shorter logs work well to form curves if any of your beds are not rectangular. If you don’t have a place where you can cut logs, call a firewood company to ask whether it will deliver what you need — logs should cost less (and last longer) than boards. Rocks, reclaimed bricks or concrete blocks are other framing options.
Best Mulches for Vegetable Gardens
Long-lasting bark mulches can be OK in pathways if you have the right kind of hoe to cut out weeds (see Hard-Working Garden Hoes).
In the growing beds, however, you’ll be happier using mulches that are finer and decompose over the season. Top choices are grass clippings, fall leaves, hay, straw, or aged fine wood chips or sawdust. Clippings and leaves are free.
If you have weed problems, simply put down cardboard or newspaper before you apply mulch.
Raised Garden Beds Pros and Cons
Numerous articles and websites claim that raised bed gardening is easier and more productive than non-raised bed gardening, but I believe most of those claims are misleading. For example, some writers assert that soil in raised beds is better. Your soil’s fertility is a function of the amounts of compost and other amendments you use; raised bed soil is not automatically more fertile. As long as you continually improve the soil in dedicated beds, whether the beds are raised, sunken or level doesn’t matter.
If you have poor or contaminated native soil, you may want raised beds with better soil brought in from elsewhere, but the soil (and probably frames) will be quite expensive. If you raise beds extra high to make them easier to reach, they will cost even more. Raised beds are a good choice if your soil drains poorly, but they’ll require more watering in most climates.