Square Foot Gardening Basics

By GardenPlanner Team · July 17, 2026

Traditional row gardening — the kind laid out for a tractor and acres of open ground — wastes a lot of space in a backyard bed. Square foot gardening, developed by Mel Bartholomew, divides a bed into a grid of one-foot squares and assigns each square a plant count based on that plant’s actual size, not a one-size-fits-all row spacing. It’s the system behind our Garden Designer.

How many plants per square?

It depends entirely on the plant’s mature size:

• Big plants (1 per square): tomatoes, peppers, broccoli, cabbage
• Medium plants (4 per square): lettuce, basil, garlic
• Small plants (9 per square): bush beans, spinach, beets
• Tiny plants (16 per square): carrots, radishes

Vining crops like winter squash and pumpkins don’t fit the grid cleanly at all — they need multiple squares’ worth of room to sprawl, which is why our designer gives them a larger footprint and nudges them toward a bed edge instead of the middle.

Why this beats rows for a home garden

Tighter spacing means less exposed soil, which means fewer weeds get a foothold and the soil holds moisture longer between waterings. It also makes planning genuinely simple: a 4×4 bed is 16 squares, and you can count exactly how many plants of each type will fit before you buy a single seed packet.

Try it without any math

Open the Garden Designer, set your bed size, and place plants — the spacing, footprint, and companion-planting warnings are all handled automatically, and there’s a “plan it for me” mode that will lay the whole bed out for you if you’d rather just pick plants and quantities.