Plant spacing calculator

Enter your bed area and desired plant spacing. Get the exact number of plants you need — for triangular spacing (the layout extension services recommend for ground covers and perennials) and square spacing (used in row-based veg gardens).

Bed and spacing

You need approximately

28 plants

Triangular spacing fits ~15% more plants in the same area than square spacing and gives a more naturalistic look. Square spacing is easier to plan and weed in straight rows — use it for vegetable gardens. For ornamental beds and ground covers, triangular spacing is the extension-recommended default.

Common spacing references

Ground covers: 6-12 inches (pachysandra 8 in, vinca 10 in, ajuga 8-12 in, lamium 12 in).

Small perennials: 12-18 inches (coral bells, dianthus, dwarf catmint).

Medium perennials: 18-24 inches (peony, daylily, coneflower, black-eyed Susan, hosta varieties).

Large perennials: 24-36 inches (large hostas, ornamental grasses, Russian sage, butterfly bush).

Shrubs: use the cultivar's mature width as the spacing. A 4 ft wide hydrangea cultivar should be planted 4 ft apart center-to-center.

Annuals (in beds): 8-15 inches depending on variety. Marigolds and petunias at 8-10 in; zinnias and snapdragons at 10-12 in; sunflowers at 18-24 in.

For vegetables, consult your seed packet — spacing varies widely by crop. Cornell Cooperative Extension publishes detailed planting charts.

Sources: Cornell Cooperative Extension, Missouri Botanical Garden plant finder profiles.