Perennial & Ground Cover Calculator: How Many Plants Do I Need?

Planning a flower bed, shade garden, pollinator patch or ground cover? Enter the size of your space and the type of plant, and this calculator tells you how many plants you need and the best-value way to buy them.

How many plants per square foot?

At 12-inch spacing you need about 1 plant per square foot. At 18 inches, about 1 plant for every 2 square feet.

Spacing by plant type

• Ground covers: about 12 inches apart for a carpet that fills in within a season or two.
• Wildflowers and small perennials: 12 inches apart for a full, meadow-style look.
• Medium perennials: 18 inches apart, the sweet spot for most garden beds and borders.
• Ferns: 18 to 24 inches apart. Larger ferns like the giant ostrich fern look best at 24 inches or more.
• Pond, wetland and rain garden plants: 18 inches apart along the edge or in moist soil.
• Large perennials and ornamental grasses: 24 to 36 inches apart so each plant has room to show off its full shape.

A simple rule: space plants about as far apart as they'll be wide when fully grown. Plant a little closer for faster coverage.

Tips for a full, beautiful bed

• Plant in groups of 3, 5 or 7 of the same plant for bold drifts of color.
• Staggered rows fill in faster and look more natural than straight lines.
• Mixing bloom times, like spring wildflowers with fall-blooming perennials, gives you color all season.
• Planting for wildlife? Browse our pollinator, butterfly and hummingbird plants.

Every plant ships from TN Nursery, a family nursery growing in Tennessee since 1959.

Planting trees, hedges or vines too? Try our Tree & Shrub Calculator, Vine Calculator or see every tool on our Planting Calculators page.

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