Plant Spacing Calculator
Tell us the size of your bed and how far apart you want the plants. We'll figure out how many you need to fill the space, with options for square or triangular layout.
What kind of space are you planting?
Pick the option that best describes your project. We'll tailor the next two questions.
How big is the space?
Measurements in feet by default. Switch to inches for tight measurements.
What's going in the ground?
Check the plant types you're using. We'll set typical spacing for each, and you can fine-tune below.
Already know what you're planting? Skip the checkboxes and use + Add a custom plant at the bottom to name it and set spacing yourself.
Common on-center spacing guide Tap to expand
- Annuals & small perennials: 6 to 12 inches
- Medium perennials: 12 to 18 inches
- Large perennials & small shrubs: 18 to 36 inches
- Mid-size shrubs: 3 to 5 feet (36 to 60 inches)
- Large shrubs & small trees: 5 to 10 feet (60 to 120 inches)
- Hedges: roughly half the mature spread (typically 18 to 36 inches for boxwood, 3 to 4 feet for laurel)
Total plants needed
Pick a space type to begin
- Bed area
- —
- Coverage per plant
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Order 10% extra to account for misshapen plants and edge fits.
New to spacing?
Read our beginner-friendly walkthrough that explains square vs triangular layouts and how to choose the right on-center distance for the plant you've picked.
Plant Spacing 101 →Want fewer decisions?
Our free Garden Planner asks a handful of questions, then matches plants from our nursery to your site and your style, with spacing and a printable layout baked in.
Open the Garden Planner →Need help choosing plants?
Book a quick landscape consultation with us and we'll walk through your space, your soil, your sun, and the look you're after. Or stop by the nursery.
Book a consultation →Common questions
How do I pick a spacing if the plant tag doesn't say?
If you have the mature spread (sometimes called "mature width") for your plant, use that as your starting point:
- For a fast, full-cover look: mature spread × 0.7 (the canopies will touch and weave together)
- For a tidy, breathing-room look: use the full mature spread (each plant stays its own clump)
- For airy or specimen plants: mature spread × 1.25 (each plant reads as an individual feature)
No tag and no info online? Ask us. Bring or send us the plant name and we'll tell you. As a rough fallback: most perennials in our zone read well at 12 to 18 inches on-center.
What if I want different plants with different spacing in the same space?
This calculator handles up to 8 different plant types at once. Each gets its own on-center spacing and a percentage of the bed.
- Hellebores at 24" filling 30% of a shady bed, heucheras at 15" filling 50%, and a sweet woodruff groundcover at 8" filling the remaining 20% — the calculator handles all three at once.
- Don't stress about exact percentages. Eyeball it. If you want 6 hellebores no matter what, the calculator's per-type breakdown will tell you what percentage that lands at.
If you're designing a bed with more than a handful of plant types and want help picking varieties that go together, our free Garden Planner walks you through site conditions and matches plants from our nursery. The spacing calculator is for "how many of these specific plants do I need." The Garden Planner is for "help me design the whole thing."
Should I use square or triangular layout? And how much extra should I order?
Triangular (staggered) layout packs about 15% more plants into the same bed and gives a fuller, more natural fill faster. It's how groundcovers and most ornamental drifts get planted in practice.
Square grid uses fewer plants and is easier to lay out by hand if you're using string or a stick to measure. Better for formal beds, hedges, and rows.
How much to add to your order:
- 10% extra for a standard rectangular ornamental bed
- 15% extra for irregular shapes, circles, or beds with tight edges where you'll lose plants to fit
- 5% extra for hedges (you're planting in a single line, so waste is minimal)
- 20% extra for groundcovers if you want first-season fill (otherwise it'll take 2 to 3 years)
What about hardscape, existing plants, hedges, and plants that spread over time?
Measure only the plantable area. Subtract paths, stepping stones, boulders, and any plants you're keeping in place. If you have a 100 sq ft bed but a 4×6 ft existing shrub stays in it, your plantable area is more like 76 sq ft.
Different uses, different spacing logic:
- Ornamental beds: use mature spread × 0.7 to 1.0 depending on look you want
- Groundcover: use mature spread × 0.5 to 0.7 for first-season fill
- Hedges: use mature spread × 0.5 (you want a solid wall, not gaps)
- Specimen / focal plants: use full mature spread or wider; they need room to be seen
Spreaders vs clumpers: spreading plants (creeping thyme, sedum, woolly yarrow, mazus) can go at the wider end of their range because they'll grow into each other within a season. Clumping plants (heuchera, hosta, daylily, peony) stay where you plant them, so use their mature spread directly without extra room.