Plant spacing calculator
Whether you are filling a bed with ground cover, planting a hedge, or laying out a vegetable patch, this tool turns bed size and plant spacing into the number of plants to buy. Switch between a square grid and staggered rows to see how many more plants a triangular layout fits.
How the plant spacing calculator works
For a rectangular bed, the calculator fits rows of plants along the length and counts how many rows fit across the width. With the typical half-spacing setback, the first plant sits half a spacing in from each edge so mature plants do not spill over. A square grid places rows one spacing apart; staggered rows place them 0.866 × spacing apart, which packs about 15 percent more plants into the same area.
The square-feet method divides total area by the area each plant occupies, which is spacing² for a grid or 0.866 × spacing² for triangular layouts. Single rows and hedges count plants along a line, with one at each end.
Formula
plants per row = floor((length − spacing) ÷ spacing) + 1
rows = floor((width − spacing) ÷ spacing) + 1 for a grid, or with spacing × 0.866 for staggered rows
Example: a 20 × 5 ft bed with plants 12 in apart fits 20 plants per row and 5 rows in a grid, for 100 plants. Staggered, rows are 10.4 in apart, so 5 rows fit, alternating 20 and 19 plants, for 98 plants in this case; in longer beds the staggered layout pulls ahead by about 15 percent.
Common spacing
| Plant | Spacing | Plant | Spacing |
|---|---|---|---|
| Pachysandra, vinca, ajuga | 8 to 12 in | Tomatoes | 24 to 36 in |
| Creeping phlox, sedum | 12 to 18 in | Peppers | 18 in |
| Hostas, daylilies | 18 to 24 in | Lettuce, spinach | 6 to 8 in |
| Liriope, mondo grass | 12 in | Tulips, daffodils | 4 to 6 in |
| Boxwood hedge | 12 to 18 in | Arborvitae privacy screen | 3 to 4 ft |
| Annual bedding plants | 8 to 12 in | Shrubs, mixed border | Mature width |
Closer spacing fills in faster but costs more and may need thinning. Once the bed is planted, finish with the mulch calculator.
Common sizes, already worked out
Common questions
How many plants do I need for 100 square feet?
100 plants at 12 in spacing in a grid, or about 115 staggered. At 18 in spacing it is 44 plants, and at 8 in it is 225. Divide the area by the spacing in feet squared.
What is triangular or staggered planting?
Each row is offset by half a spacing from the row before it, so every plant sits in the gap of the previous row. Rows end up closer together, fitting about 15 percent more plants and hiding bare soil sooner.
Should I space plants by pot size or mature size?
Mature size, from the plant tag. A one-gallon shrub that grows 4 ft wide needs 4 ft of space even if it looks lost at first. Fill the gaps with annuals or mulch until it grows in.
How far from the edge of the bed should I plant?
Half the plant spacing. A plant that will be 12 in wide needs 6 in from the edge so it does not grow over the lawn or walkway. For hedges along a fence, allow half the mature width plus room to trim behind.