Build a square-foot garden

Square-foot gardening is an easy way to harvest a succession of fresh produce from the smallest of yards and even those with poor soils. Developed by Mel Bartholomew in the early 1980s, the concept remains popular today because it offers a simple plan for growing vegetables in compact, raised beds that can be intensively planted with a variety of crops.

A square-foot garden can be confined to one or as many raised beds as the yard can accommodate. The basic unit is a shallow, 12-inch deep box measuring 4 feet by 4 feet, which rests on top of the ground. Filled with soil, the raised bed is then divided into 16 one-foot squares, each one planted with a single type of vegetable or herb. Because of the limited space, spreading plants such as cucumbers and squash can be trained to grow up obelisks or bamboo tepees. It’s more difficult to accommodate root vegetables, such as potatoes, which need greater soil depth, so these might be better grown in a conventional plot.

The compact dimensions of the raised bed make it easy to reach crops from all sides to weed, water and fertilize. Gravel pathways separating the beds—if you have more than one—allow easy access and also reflect sunlight and warmth so vegetables establish and grow more quickly than in conventional gardens.

Here’s how to build a square-foot garden in your backyard:

1. Because most vegetables and herbs grow best in sun, find a spot that receives at least six hours of sunlight daily. Ideally, choose a location handy to the kitchen that is close to a water source, too.
2. The wooden frame for the raised bed can be constructed at any time of the year—even during the winter in a large basement workroom or in a heated garage—then, assembled on site at the start of the growing season.
3. To build the frame, cut eight four-foot lengths of 2 x 6 cedar or pressure-treated lumber. Screw or nail four of the planks together to form a box, reinforcing each corner with a 12” long 4 x 4 post (or use heavy gauge corner hinges available at specialty stores). Repeat with the remaining four planks to form a second tier so the sides of the box are 12” deep.
4. Spread newspapers or landscape cloth on the ground to help suppress weeds. Then, fill the box with a mix of equal parts topsoil, compost and manure. Rake soil evenly.
5. Using pushpins, tacks or finishing nails, divide each side of the box into four one-foot sections. Then, form a grid of 16 squares by running parallel lengths of string from side to side across the bed using the pushpins as a guide.
6. Plant one type of vegetable or herb in each square of the grid, siting tall ones at the north side so they don’t block the sun. One large plant, such as tomatoes or pole beans, might take up an entire square while larger numbers of smaller ones—radishes and scallions, for example—can be sown in others. Then, remove the string. To prevent overcrowding, consult packet directions to determine spacing requirements, and thin out seedlings as they grow. Plants growing in each square will weave naturally into those in other squares, forming a pleasing quilt-like effect. Water, weed and fertilize as you would in a conventional garden.
7.  When early crops have been harvested, replace them with a late-season vegetable, such as cabbages, kale or a second sowing of carrots, topping up and enriching the soil with compost.

Enjoy growing and harvesting your vegetables!

Lorraine Flanigan is a freelance writer and editor with a passion for gardening. You can read her personal gardening journal at City Gardening.

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