Plant Spacing Calculator

This plant spacing calculator shows how many plants fit in a bed or row. Choose a plant from the list to use its recommended spacing, or enter your own. Then pick a square grid, an offset (triangular) grid or traditional rows, and enter the size of the space. The calculator places plants half a spacing in from every edge, so the count reflects what actually fits, not just a division of the area. It also shows the layout, the density in plants per square foot and the typical row spacing for row gardens.

How to use the plant spacing calculator

1. Choose the plant. The list uses typical spacing from our plant database. Choose custom spacing if your seed packet gives a different figure or your plant is not listed.
2. Choose the pattern. Square grids are easiest to lay out. Offset grids fit more plants into large beds. Rows suit in-ground gardens with walking paths between rows.
3. Enter the bed length and width in feet. For raised beds, use the inside dimensions.
4. For rows, enter the row spacing. The result also shows the typical row spacing for the chosen crop.
5. Read the count. The headline number is how many plants fit, and the table shows the layout so you can mark it out.

Three ways to space plants

Square grid

Plants sit at the corners of squares, in straight lines in both directions. It is the simplest pattern to plant and to weed between, and it matches the way most people lay out raised beds. The count is the number that fits along the length multiplied by the number that fits across the width.

Offset (triangular) grid

Every other row is shifted by half a spacing, so plants sit at the points of equilateral triangles. Each plant is still the same distance from its neighbors, but the rows sit closer together, at about 87 percent of the spacing. Over a large area this fits roughly 15 percent more plants than a square grid at the same spacing, and it covers the ground more evenly, which shades out weeds sooner. In small beds the gain can disappear, because the shifted rows lose a plant at the ends.

Rows

Plants are spaced closely within each row, and rows are set wider apart to leave room for walking, hoeing or a tiller. This is the traditional pattern for in-ground vegetable gardens and larger plots. It uses space less intensively than a grid, but it is easier to manage at scale.

How the count is worked out

Each plant needs a circle of space with a diameter equal to its spacing. To keep leaves inside the bed, the first plant sits half a spacing in from the edge. That means the number of plants along a side is the side length in inches divided by the spacing, rounded down.

Plants along a side = floor(side length in inches ÷ spacing)
Square grid = plants along the length × plants across the width
Offset rows sit 0.866 × spacing apart

A rougher shortcut, useful for large areas, is to divide the area in square inches by the spacing squared. For a square grid that gives plants per area, and for an offset grid you divide by an extra 0.866. The calculator does the exact count instead, because edges matter a lot in small beds.

Worked example: lettuce in a 4 by 8 bed

Leaf lettuce at 8 inches apart in a 4-by-8-foot bed: the bed is 96 inches long and 48 inches wide. That fits 12 plants along the length and 6 across, so a square grid holds 72 plants. An offset grid fits 6 rows alternating 12 and 11 plants, or 69 plants, slightly fewer because of the short ends. In a bed this size the square grid is the better choice.

Worked example: a large plot

The same lettuce in a 20-by-20-foot area fits 900 plants in a square grid and about 1,003 in an offset grid, an 11 percent gain. The larger the area, the closer the offset pattern gets to its theoretical 15 percent advantage.

Worked example: tomatoes

Tomatoes at 24 inches in a 4-by-8 bed fit 4 along the length and 2 across, which is 8 plants. That is a typical number for staked or caged tomatoes in a bed this size. With aggressive pruning and tall stakes, some gardeners plant closer, but crowded tomatoes are more prone to leaf diseases.

Typical spacing for common crops

These are typical in-row spacings for home gardens. Your seed packet may differ for a particular variety.

The full list, with row spacing, sowing depth and days to maturity, is in the plant database. For planting by the square foot, the square foot gardening calculator uses the same figures.

Why spacing matters

Spacing is a balance between yield per plant and yield per square foot. Plants given plenty of room grow larger individually, but you get fewer of them. Plants packed tightly compete with each other, but the bed as a whole can produce more, up to a point. Past that point, crowding costs you in several ways.

• Disease: crowded foliage dries slowly after rain or watering, which favors fungal diseases such as early blight on tomatoes and powdery mildew on squash.
• Competition: roots compete for water and nutrients, so plants stay smaller and need more frequent watering and feeding.
• Light: taller plants shade their neighbors, and fruiting crops produce less in shade.
• Access: you need to reach in to harvest, prune and check for pests. Crops you cannot reach tend to get neglected.

Too much space has costs too. Bare soil between plants invites weeds and loses moisture to evaporation, and you have paid to build and fill bed space that produces nothing. Mulch helps fill gaps while plants grow.

Intensive planting in raised beds

Raised beds allow closer spacing than row gardens, for two reasons. You never walk on the soil, so roots can spread through loose ground, and the soil is usually richer than native ground. Most raised bed gardeners use the in-row spacing from the seed packet in both directions and ignore the row spacing entirely. That is what the square and offset patterns in this calculator do.

When planting intensively, feed and water accordingly. A densely planted bed draws more water and nutrients than the same bed planted sparsely, so a yearly top-dressing of compost and regular watering become more important.

Spacing for rows

In a row garden, the row spacing mostly sets the path width. Typical row spacing ranges from about 12 inches for small crops such as carrots and lettuce up to 3 to 6 feet for sprawling squash and melons. If you hoe by hand, rows can be closer. If you use a tiller between rows, set the spacing at least a few inches wider than the tiller.

A useful compromise is the wide row or bed system: plant a band 1 to 3 feet wide using grid spacing, then leave a path between bands. You get much of the efficiency of a raised bed without building frames.

Getting more from the same space

• Grow up. Trellising cucumbers, pole beans, peas and indeterminate tomatoes lets them occupy far less ground. A trellised cucumber can be grown at 12 inches instead of sprawling over several square feet.
• Interplant. Sow quick crops such as radishes or lettuce between slow crops such as tomatoes or broccoli. The quick crop is harvested before the slow one needs the space.
• Succession plant. Follow early crops with later ones in the same space. The plant database shows days to maturity to help you plan.
• Choose compact varieties. Bush, patio and determinate varieties are bred to need less space than their full-size relatives.

Thinning to the right spacing

Small seeds are usually sown more thickly than the final spacing, then thinned once seedlings have their first true leaves. Thin in stages: first to about half the final spacing, then to the full spacing once you can see which seedlings are strongest. Snip unwanted seedlings at soil level with scissors rather than pulling them, which avoids disturbing the roots of the ones you keep. Thinnings of lettuce, beets and other greens are perfectly good to eat.

To work out how many seeds to buy for your spacing, use the seed quantity calculator.

Common spacing mistakes

• Spacing for the transplant, not the mature plant. A tomato seedling looks tiny, but it will fill a 2-foot circle by midsummer.
• Skipping thinning. Unthinned carrots and beets stay small and misshapen.
• Using row spacing in raised beds. It wastes a large share of the bed.
• Ignoring variety differences. A vining squash and a compact bush squash need very different space.

Spacing perennials, shrubs and flowers

The same calculator works for ornamental plantings, but the right spacing number is different. For perennials and shrubs, spacing is usually based on the plant’s mature width, which is printed on the nursery tag. Plants spaced at their full mature width will just touch when fully grown, which can take two to five years for shrubs and two or three seasons for many perennials.

Many designers space perennials at about two-thirds to three-quarters of their mature width, so the bed fills in sooner and leaves less bare ground for weeds. Groundcovers are often planted closer still, at 8 to 12 inches, so they knit together within a season or two. Annual bedding plants such as petunias and marigolds are typically spaced 8 to 12 inches apart for a full display in one summer.

For a natural look in mixed borders, offset spacing works better than a square grid, because plants in straight lines look regimented. Planting in groups of three, five or seven of the same plant, each group spaced on an offset grid, is a common way to get both good coverage and a relaxed appearance.

Shrubs planted as a hedge are an exception. They are usually spaced at about half their mature width, so neighboring plants grow together into a continuous screen. Spacing depends on the species and how quickly you want privacy, so check the nursery’s recommendation for hedge planting specifically.

Frequently asked questions