Seed Spacing Calculator

About This Tool

The Seed Spacing Calculator takes the guesswork out of garden planning. Select your crop, enter your bed dimensions, and choose between traditional row gardening or the popular square foot gardening method. The calculator tells you exactly how many plants fit in your space and the correct spacing for each.

Row Gardening vs Square Foot Gardening

Traditional row gardening spaces plants in rows with wider walkways between them. It is easier to cultivate with tools and works well for large gardens. Square foot gardening divides the bed into a grid of 1-foot squares, each planted with a specific number of plants based on their size. SFG produces more food per square foot but requires richer soil and more careful planning.

Why Spacing Matters

Correct spacing ensures plants get enough light, water, and nutrients without competing. Too close together and plants become spindly, prone to disease from poor air circulation, and produce less fruit. Too far apart and you waste valuable garden space. The spacing in this calculator reflects proven recommendations from university extension services and seed companies.

Succession Planting

For continuous harvest, plant quick-growing crops like lettuce, radishes, and beans every 2-3 weeks throughout the season. As one batch is harvested, the next is ready. This is especially powerful in square foot gardening where you can replant individual squares as they empty out. A single 4x8 bed can produce several hundred pounds of vegetables per year with succession planting.

Companion Planting

Some plants grow better together. Tomatoes thrive near basil and carrots. Beans fix nitrogen that benefits corn and squash (the classic Three Sisters planting). Marigolds repel many garden pests. When planning your garden layout, consider which crops make good neighbors and which should be kept apart.