Forty-pound bags of top soil make nifty instant no-dig garden beds.
Illustration by Elayne Sears
Is this the year you finally start a garden? Or maybe you long for one more bed of bush beans, or you need space for one last pair of tomatoes. Although it’s best to dig or till the soil before you plant, it isn’t essential. Here are several ways to create usable planting space with no-dig gardening. Later on, when the season winds down and you have more time, you can turn this year’s instant garden beds into primo permanent planting space.
Easiest No-Dig Gardening Options
The best way to start a new garden bed is by digging a new site to incorporate organic matter and remove weeds. But in a pinch you can just cover the area with cardboard or layers of wet newspaper, followed by several inches of grass clippings, shredded leaves or weed-free hay or straw. Use a hand trowel to pull back the mulch, cut away sod, and open up planting holes for stocky transplants, including tomatoes, peppers, eggplants, cucumbers, herbs, flowers — whatever transplants you can buy will work.
If your soil is hopelessly hard and infertile, line your car trunk with a tarp or old shower curtain, and head to a garden center for a load of 40-pound bags of topsoil. (If you can’t decide between products and brands, buy an assortment and put them to the test.) Slash drainage holes in the bottoms of the bags, then lay them over the area you want for your growing bed. Use a sharp utility knife or scissors to cut away the tops of the bags. Moisten well, then plant the bags with seeds or transplants, and mulch to cover the bags. (When growing tomatoes in bags, allow one bag of topsoil per plant.)
Straw Bale Solutions
In 2004, following the lead of horticulture professors N. L. Mansour from Oregon State and James Stephens in Florida, Rose Marie Nichols McGee and dozens of volunteers grew colorful salad greens in compost-enriched bales of hay and exhibited them at the Northwest Flower and Garden Show to promote the “Plant-A-Row for the Hungry” program. Since then, thousands of gardeners (including me) have tried straw bale beds, which have their pros and cons. On the plus side, you can put one anywhere, and if it’s kept moist all season, the area beneath the bale will show rapid improvement in drainage and tilth thanks to the work of big night crawlers, which thrive beneath straw bale beds. (For more on these beneficial critters, see Worms! Soil-building Workhorses. On the down side, bale beds need a lot of supplemental water and liquid fertilizer, but they are still fun and rewarding to grow.
To get large-scale “instant” results, use bales of straw or hay to frame a big raised bed (arranged in a rectangle, a 15-bale instant garden bed will have an 8-by-20-footfootprint). Fill the enclosure with as much soil, compost and any other free or cheap growing mediums you can find. You’ll need a truckload or two, so ask around for a source of well-rotted manure, or maybe your local garden center sells its “spent” potting soil. Allow several days of intermittent watering to thoroughly moisten the growing medium and the bales, and then plant vegetables inside and on top of your straw bale barge. As long as you can keep this setup moist (soaker hose coverage and mulch are mandatory), it will support a huge array of summer vegetables, and decompose into a beautiful bed of organic matter in about a year.
The Frame Game
Other easy ways to create instant beds involve setting up a frame of some kind, and filling the frame with growing medium. The frame can be a temporary affair made from plastic fencing or untreated boards, or you can build frames from scrap lumber, slender logs or stacked block or stone. Or talk to a fencing company about recycling rails from discarded cedar rail fencing. You don’t need to build four-sided frames — just lay two long rails or logs parallel to each other and fill with soil.
Should you decide to buy framing materials, plastic fencing planks are lightweight and easy to use. Many work with snap-together corner connectors, and many stores carry matching planks and connectors, which are made from recycled plastic and can be mounted on short wood posts. I always need a new bed somewhere, so I’ve invested in heavy, termite-proof composite decking planks. Recycled plastic corner connectors I bought from Gardener’s Supply 12 years ago have helped me plop down instant garden beds in three states, and they show no signs of giving up. My corner connectors are quite similar to the Raised Bed Corners, still sold by Gardener’s Supply, as well as the Multi-level Raised Bed Stakes sold by Lee Valley Tools.
If you want a more natural frame, a “bird nest” made with brush or stalks and filled to overflowing with compost and soil, is a great way to grow pumpkins or winter squash.
Fill ’Er Up
The fastest no-dig gardening way to get a framed instant garden bed ready to roll is to fill it with good quality topsoil mixed with compost (see “Bags or Bulk?” below). Using a planting mix makes it possible to set up and plant a new bed within a few hours, and because commercial topsoils and planting mixes are usually free of weeds, they set the stage for a nearly weedless season. In the interest of long-term soil fertility, it’s a good idea to add some fresh green grass clippings or other finely chopped tidbits of fast-rotting organic matter if you can. In addition to providing nutrients plants can use, a sprinkling of juicy green stuff will attract the attention of the soil microorganisms that are the core producers of healthy, fertile soil
There are plenty of other bed-building options. In Lasagna Gardening, author Patricia Lanza recommends covering a new site with newspapers and shredded leaves, followed by alternate layers of compost and peat moss. In Square Foot Gardening, advocate Mel Bartholomew’s favored mix is a three-way blend of peat moss, compost and vermiculite. Either will work, but if you’d rather not use peat moss that’s been dug from ancient bogs, processed and shipped hundreds of miles, simply stick with a mixture of compost and soil. And take note: Gardeners who have access to mushroom compost swear by its amazing ability to support plants grown under lean, first-year conditions. For best results, mix mushroom compost with an equal amount of soil taken from another part of your yard when using it to fill a bed.
In my latest book, The Complete Compost Gardening Guide, co-author Deb Martin and I share what we learned over three seasons of using “comforter compost” beds to grow peas, beans, squash and even tomatoes in unimproved sites. The idea is simple: Build a compost pile where you want a new bed, and include soil in the sandwich so that plant roots can anchor themselves comfortably in place. Because they are so bioactive, comforter compost beds are gluttons for mulch, and without mulch they dry out quickly.
Instant garden beds are typically aboveground projects that are installed quickly, without laborious digging of the site. However, if you want to develop the site into excellent growing space in the future, eventually you will need to loosen up the subsoil and work in generous helpings of compost. But why rush? Deep digging of a new site is much easier after it has mellowed below an instant garden bed for a season, so throwing together quickie beds is a simple way to begin the soil improvement process.
Keep in mind that plants grown in instant garden beds will probably need more water and fertilizer than plants that can easily send roots deep into fertile soil. Locating instant garden beds within easy reach of a water supply — and equipping them with soaker hoses — can make the difference between easy success and frustrating failure. You will also find that some crops do better than others, with the best performances delivered by fast-growing summer veggies. In late summer, you can start a new round of instant garden beds for easy-to-please leafy greens. Adding a plastic cover to foil early freezes could mean homegrown salads for the winter holidays.
Any instant garden bed will cause beneficial changes to the soil beneath it, but some soils need far more help than passive top-down methods can provide. Unless you are blessed with deep, fertile topsoil, sooner or later you will want to physically merge enriched topsoil with impoverished subsoil, which may require serious digging. In one place I started new beds, I needed a miner’s pick to crack into the compacted clay. Still, spots that have been primed with instant garden beds are always easier to dig.
Seven No-dig New Bed Options
- Lay down cardboard, mulch, set out transplants.
- Plant directly into bags of topsoil.
- Make frame with straw bales and fill.
- Use wood frames and fill with compost or topsoil.
- Build a “bird nest” from brush and fill.
- Make “lasagna” — layers of leaves, peat moss and compost.
- Build compost pile, add soil and plant.
Bags or Bulk?
Buying topsoil or compost in bags is fast and convenient, but how does it compare to buying in bulk? Prices for 40-pound bags of compost-amended topsoil (garden soil) range from $2.30 to $8, so it pays to shop around. You will probably find locally produced products that compete favorably with Black Velvet, a national brand with a nice price tag of $2.50 per 40-pound bag. When used to make instant beds, one such bag will cover about 2 square feet.
These big bags typically contain 1 cubic foot by volume, whereas a “scoop” or “bucket” of bulk compost or planting mix contains 20-plus cubic feet, depending on the size of the tractor’s front-end loader. Large buckets carry a full cubic yard, or 27 cubic feet (the equivalent of 27 bags). Bulk compost made from yard waste can cost less than $20 per scoop, but expect to pay twice that much for screened, aged organic farm compost mixed with good topsoil. Use the numbers below for comparing bulk and bagged prices.
Price per Price per
Cubic YARD Cubic FOOT
$20 = $0.74
$30 = $1.11
$40 = $1.48
$50 = $1.85
$60 = $2.22
Price per Price per
Cubic FOOT Cubic YARD
$2 = $54
$3 = $81
$4 = $108
$5 = $135
$6 = $162
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.