What does centre-to-centre spacing mean?

Spacing is measured from the centre of one plant to the centre of the next. A 30 cm spacing means each plant centre is 30 cm from its neighbours.

What is staggered (triangular) planting?

Every other row is offset by half the spacing. This gives more even coverage and fits about 15% more plants in the same area than a grid pattern.

How do I know the right spacing?

Check the plant label or RHS guidance. Spacing depends on the mature spread of the plant. Closer spacing gives quicker coverage but plants may become crowded.

Should I include edge spacing?

Usually plant the first row half-spacing from the edge. This calculator assumes you plant from edge to edge of the given area.

Does spacing change for container planting?

In containers, plants are often placed slightly closer together than in open ground because you control watering and feeding. Reduce spacing by about 20% for container displays.

GardenCalcs

Plant Spacing Calculator — How Many Plants Do I Need

Calculate how many plants you need for a given area and spacing.

Bed Length

Bed Width

Plant Spacing

Planting Pattern

How We Calculate This

Grid pattern: Rows = Floor(Width ÷ Spacing) + 1. Plants per row = Floor(Length ÷ Spacing) + 1. Total = Rows × Plants per row.

Staggered pattern: Row spacing = Spacing × 0.866 (triangular offset). Alternate rows have one fewer plant. This gives approximately 15% more plants per area.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.