How many plants per square foot?

It depends on the crop's size class. Extra-large crops such as cabbage, broccoli, and peppers get 1 plant per square foot. Large crops such as lettuce, Swiss chard, basil, and parsley get 4. Medium crops such as spinach, beets, and bush beans get 9. Small crops such as radishes, carrots, and onions get 16.

What is the square foot gardening spacing chart?

It is the four-class table from the method Mel Bartholomew published in 1981: a bed is divided into one-foot squares, and each square holds 1, 4, 9, or 16 plants depending on the size class of the crop. It replaces the row spacing printed on seed packets, which wastes space in a square bed.

How far apart should plants be in square foot gardening?

Spacing follows from the count per square rather than a measured gap. Four plants per square works out to about 6 inches apart, nine per square to about 4 inches, and sixteen per square to about 3 inches. For a crop not on the chart, divide 12 by the seed packet's row spacing in inches and square the result to get plants per square foot.

Guide

Square-foot planting chart: how many plants actually fit per square

The footprint of the Vertical Grow System is nine one-foot squares. Square-foot gardening has a specific rule for how many plants go in each one, and it isn't always one.

By Moses Emmanuel · Reviewed by Romain Lefebvre

The spacing rule

Square-foot gardening is a method the retired engineer Mel Bartholomew developed and published in 1981, built around dividing a bed into one-foot squares instead of planting in rows. It sorts vegetables into four size classes, and each class gets a fixed number of plants per square:

Extra-large — 1 per square. Cabbage, broccoli, cauliflower, peppers.
Large — 4 per square. Leaf lettuce heads, Swiss chard, basil, parsley.
Medium — 9 per square. Spinach, beets, bush beans, bush peas.
Small — 16 per square. Radishes, carrots, onions.

Four one-foot squares side by side, showing 1, 4, 9, and 16 plant positions marked in each, from largest to smallest spacing class

This is different from the seed-packet spacing on most commercial seed bags, which is written for row gardening and wastes space in a square bed. The square-foot count assumes plants touching their neighbors at maturity, which works because a raised bed's soil isn't compacted by foot traffic the way row-garden soil is.

Exact counts, crop by crop

The four-class shorthand above is the popularized version. County extension course notes taken from a class Bartholomew taught in person break the same method down crop by crop instead of by size bucket, and a few land in a different spot than the four-class summary suggests: basil and parsley come out at 4 per square there, not 9, while beets and garlic come out at 9, not 4 or 16. Neither number is wrong — spacing charts vary a little by source and by how tightly you're willing to crowd a given variety — but crop-specific counts are the ones to use if the four-class shorthand and a seed packet disagree.

Broccoli, kale, collards, cabbage, potatoes1 per square

Corn, okra2 per square

Bok choy, fancy & European lettuce, Swiss chard, soy beans, fava beans, basil, parsley, cilantro, oregano, mint4 per square

Green (string) beans5 per square

Beets, turnips, spinach, peas, garlic9 per square

Carrots, radishes, green onions, small bulb onions16 per square

Applying it to a 3-by-3-foot, 4-tier frame

The Vertical Grow System's footprint is nine squares. With four tiers, that's nine squares repeated four times, not thirty-six independent squares stacked freely: each tier is still one 3-by-3 layer, and what you plant in it depends on how much light that tier gets.

Top tier (full sun)1 large plant per square, e.g. lettuce

Upper-mid tier (part sun)9 medium per square, e.g. spinach, peas

Lower-mid tier (part shade)4 large per square, e.g. strawberries, basil, parsley

Bottom tier (cool shade)16 small per square, e.g. radishes

At those counts, a fully planted top tier holds 9 lettuces, the upper-mid tier holds up to 81 spinach or pea plants, the lower-mid tier holds 36 strawberry, basil, or parsley plants, and the radish tier holds up to 144. Most people plant fewer than the maximum, especially on the herb and radish tiers, to leave room to harvest without disturbing neighboring roots. Counts are only half the question, since whether two different crops can share a square depends on root depth, water demand, and height rather than on the counts, which is what our companion planting chart works through.

Why not just say "one crop per square"

Treating every square as a single planting slot is the easiest way to start, and it's a reasonable default for a first season. It undercounts what the frame can actually hold once you're comfortable spacing smaller plants closer together, which is the entire point of the square-foot method over row planting.

This chart covers the common size classes. For a vegetable not listed here, check the seed packet's row spacing in inches and divide 12 by that number, squared, to estimate plants per square foot.