Plant spacing calculator
Enter the bed size and plant spacing to get how many plants you need. An offset (triangular) grid fits about 15% more plants than a square grid.
Enter your measurements
More options: Price
- Density
- 1.00 plants per sq ft
- Bed area
- 100 sq ft
10 ft × 10 ft = 100 sq ft
each plant needs (12 in)² = 1 sq ft
100 sq ft ÷ 1 sq ft = 100 plants
- Keep the outer row about half a spacing in from the edge of the bed. The count assumes that layout.
Quick answers for common sizes
| Example | Answer |
|---|---|
| How many plants for a 10×10 bed at 12 inch spacing | 100 plants |
| How many groundcover plants for 200 sq ft at 8 inch spacing | 520 plants |
Plants needed by spacing
| Spacing between plants | Plants needed | Density |
|---|---|---|
| 6 in | 400 plants | 4.00 plants per sq ft |
| 8 in | 225 plants | 2.25 plants per sq ft |
| 12 in | 100 plants | 1.00 plants per sq ft |
| 18 in | 45 plants | 0.44 plants per sq ft |
| 24 in | 25 plants | 0.25 plants per sq ft |
| 36 in | 12 plants | 0.11 plants per sq ft |
At the same spacing, an offset grid also covers the ground more evenly, which is why groundcovers and mass plantings are usually laid out that way.
How the plant count works
Each plant "owns" a small patch of ground. On a square grid that patch is spacing × spacing. On a triangular grid — each row offset by half a spacing — the rows sit closer together (0.866 × spacing apart), so each plant owns about 13% less ground and the bed fits about 15% more plants.
square grid: plants = area ÷ spacing² triangular grid: plants = area ÷ (spacing² × 0.866) (area and spacing in the same units — e.g. both in sq in / in)
| Spacing | Plants per sq ft (square) | Plants per sq ft (triangular) |
|---|---|---|
| 6 in | 4.00 | 4.62 |
| 8 in | 2.25 | 2.60 |
| 12 in | 1.00 | 1.15 |
| 18 in | 0.44 | 0.51 |
| 24 in | 0.25 | 0.29 |
A quick check from Washington State University Extension’s spacing notes: 100 plants at 6 in spacing cover about 25 sq ft, and at 12 in about 100 sq ft. Two worked examples: how many plants for a 10×10 bed at 12 inch spacing and how many groundcover plants for 200 sq ft at 8 inch spacing.
Hedges and single rows
For a hedge, border or fence-line planting, the count is linear: row length ÷ spacing, plus one plant for the far end. A double staggered row — two lines offset by half a spacing, in a zigzag — uses roughly twice the plants and closes into a solid screen faster. Choose Single row or Double staggered row in the layout box. WSU Extension suggests about 18 in between plants for low hedges of 3–4 ft and 3–4 ft for tall hedges, closer than the same shrubs would be planted as specimens.
single row: plants = row length ÷ spacing + 1 double staggered row: second row starts half a spacing in
Choosing a spacing
Use the spacing on the plant tag — it is usually based on the plant’s mature width. Closer spacing fills in faster but costs more and can crowd plants later; wider spacing is cheaper, but you will be weeding bare ground for a season or two. University of Illinois Extension suggests a staggered (diamond) pattern for groundcovers, spacing fast growers further apart than slow ones, and allowing one to two growing seasons for full cover.
Shrubs along a house need room from the wall as well as from each other: WSU puts small shrubs at least 2 ft from the foundation and medium ones about 3 ft. Mulching that bed afterwards? See how much pine straw for a 3×60 ft foundation bed.
Tips
- Lay out all the pots on the bed before digging any holes. It is easy to adjust then.
- For groundcovers sold in flats, divide the plant count by the cells per flat and round up.
- Mulch between new plants so weeds don’t fill the gaps first.
- For vegetables, the square foot method uses per-square counts instead: see how many plants fit in a 4×4 square foot garden.
What you’ll need
- Coated work glovesBudget price
Grippy, cut-resistant palms for handling stone, block and bags. Buy a couple of pairs — they wear out fast on concrete block.
See options on Amazon (opens in a new tab) - Measuring wheelBudget price
Rolls off long distances — driveways, lawn edges, fence lines — quicker and more accurately than a tape for one person.
See options on Amazon (opens in a new tab) - Mulch / manure forkBudget price
Many tines grip shredded mulch and compost that slide off a shovel. Much faster for spreading bulk mulch.
See options on Amazon (opens in a new tab) - Soaker hoseBudget price
Weeps water slowly along its length — good for beds and rows, and low enough pressure to run from a rain barrel.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many plants do I need at 12 inch spacing?
One per square foot on a square grid, or about 1.15 per square foot on an offset grid. A full example is in how many plants for a 10×10 bed at 12 inch spacing.
Is triangular spacing better than square?
For groundcovers and mass plantings, usually. It fits about 15% more plants, covers more evenly, and leaves no long straight gaps. Square grids are simpler for vegetables and for plants you need to walk between.
How far apart should I plant groundcover?
It depends on the plant and how fast you want coverage — commonly 6–18 in, with fast spreaders set further apart than slow ones (University of Illinois Extension). See how many groundcover plants for 200 sq ft at 8 inch spacing.
How many plants do I need for a hedge?
Divide the row length by the spacing and add one for the end plant. A 30 ft row at 3 ft spacing is 11 plants. A double staggered row roughly doubles that and fills in sooner. Hedge spacing is tighter than specimen spacing: WSU Extension suggests about 18 in for low hedges and 3–4 ft for tall ones.
Sources
- Washington State University Extension C132: Spacing of Landscape Plants (opens in a new tab) — Groundcover coverage by spacing (100 plants at 12 in ≈ 100 sq ft); hedge spacing; shrub distance from foundations
- University of Illinois Extension: Ground Covers (opens in a new tab) — Staggered/diamond pattern; spacing depends on growth rate and budget; 1–2 seasons to fill in