Square-foot gardening

The per-square counts

Divide 12 inches by the plant's in-row spacing and square the result. A crop spaced 3 inches apart gives 16 per square (carrots, radishes); 4 inches gives 9 (beets, spinach, bush beans); 6 inches gives 4 (lettuce, chard, basil); 12 inches gives 1 (tomato, pepper, broccoli, cabbage).

Large sprawling crops — winter squash, melons, indeterminate tomatoes without support — do not fit the grid and need one plant across two or more squares plus a trellis.

The bed and the mix

Classic beds are 4×4 feet and 6–12 inches deep, with a physical grid laid on top. Deeper is better for root crops and for anything you want to grow through a dry spell.

The traditional fill is equal parts compost (from several sources), peat moss or coco coir, and coarse vermiculite. The raised bed soil calculator gives the cubic feet of each for your bed size.

Where it shines

Beginners planning a small space, succession replanting (you refill one square at a time), and keeping track of rotation. Close spacing also shades out weeds once plants fill in.

Where to bend the rules

Heavy feeders like tomatoes and squash often do better with more room and airflow than the grid allows, which reduces disease. In hot, dry climates, very tight spacing competes for water. Treat the counts as a sensible maximum, not a target.

Planting a square, step by step

Lay a grid of string, lath or thin wood across the bed so every square foot is visible - it's what keeps the spacing honest. For each square, divide it into the number of planting spots: one in the middle, four in a 2-by-2, nine in a 3-by-3 or sixteen in a 4-by-4. Press a finger into the soil at each spot to the sowing depth, drop in a seed or two, and cover.

Thin to one plant per spot once seedlings have their first true leaves, snipping the extras at soil level rather than pulling them. When a square is harvested, add a trowel of compost and replant it straight away with something from a different family - that one-square-at-a-time rhythm is the method's biggest strength, and the succession planting planner helps schedule it.

Growing up, not out

Put a trellis along the north edge of the bed so it doesn't shade the rest. Vining crops then fit the grid: one indeterminate tomato per square tied to a stake or string, cucumbers at two per square, and peas or pole beans at eight per square along the trellis. See vertical gardening and trellising for supports that hold up.

Watering and feeding a packed bed

Close spacing means more roots in less soil, so a square-foot bed dries out faster than an in-ground row, especially in its first year. Check moisture a couple of inches down every day or two in summer; a soaker hose or drip line snaking through the grid saves a lot of hand-watering.

Because the bed is replanted square by square through the season, top it up with compost every time you replant rather than relying on the original fill. Most beds also need a light topping of compost across the whole surface each spring as the mix settles and breaks down.

Common questions