How to Choose the Right Spacing
Plant spacing is determined by the mature spread of the plant, not its size at purchase. A hydrangea that looks small in a 3-gallon pot will spread to 4 to 6 feet wide at maturity. Spacing too close creates overcrowding, disease pressure, and expensive thinning later. Spacing too far leaves gaps that weeds colonize and looks sparse for years.
The general rule: space plants at 75% of their mature width for a full, slightly overlapping look within 2 to 3 years. For a tighter look sooner, space at 50% of mature width (but expect to thin eventually).
Common Plant Spacing Reference
| Plant Type | Typical Spacing | Example Plants |
|---|---|---|
| Ground cover | 6 to 8 inches | Creeping phlox, ajuga, sedum |
| Annual flowers | 6 to 12 inches | Petunias, marigolds, impatiens |
| Perennial flowers | 12 to 18 inches | Daylilies, coneflowers, hostas (small) |
| Small shrubs | 18 to 24 inches | Boxwood, spirea, dwarf varieties |
| Medium shrubs | 24 to 36 inches | Hostas (large), ornamental grasses |
| Large shrubs | 36 to 60 inches | Hydrangeas, viburnums, lilacs |
| Hedge plants | 24 to 36 inches | Arborvitae, privet, boxwood (hedge) |
Buying Tips
Buy 5 to 10% more plants than the calculator suggests. Transplant losses happen, especially with bare-root plants and in hot weather. Having a few extras for replacement is cheaper than a second trip to the nursery. Most nurseries will take returns on healthy, unused plants within a reasonable window.
