Plant Spacing & Bed Layout Calculator
Calculate how many plants fit in a garden bed and visualize the layout based on bed dimensions and plant spacing requirements.
Formulas Used
Usable Dimensions:
Usable Length = Bed Length − 2 × Border Gap
Usable Width = Bed Width − 2 × Border Gap
Grid (Square) Pattern:
Columns = ⌊Usable Length / Spacing⌋ + 1
Rows = ⌊Usable Width / Spacing⌋ + 1
Total Plants = Rows × Columns
Offset / Triangular (Hexagonal) Pattern:
Row Spacing = Plant Spacing × √3 / 2 ≈ 0.866 × Plant Spacing
Number of Rows = ⌊Usable Width / Row Spacing⌋ + 1
Even rows: Plants = ⌊Usable Length / Spacing⌋ + 1
Odd rows: Plants = ⌊(Usable Length − Spacing/2) / Spacing⌋ + 1 (offset by half spacing)
Total Plants = Sum of plants across all rows
Packing Efficiency:
Grid: π/4 ≈ 78.54% | Hexagonal: π/(2√3) ≈ 90.69%
Assumptions & References
- Bed dimensions are entered in feet; spacing and border gap are in inches.
- The border gap represents the minimum distance from the bed edge to the first plant, applied on all four sides.
- Grid pattern places plants at equal spacing in both directions, forming a square grid.
- Offset (triangular/hexagonal) pattern staggers alternate rows by half the plant spacing, achieving denser packing — approximately 15% more plants than a grid layout.
- Row-to-row distance in the offset pattern is derived from equilateral triangle geometry: h = s × sin(60°) = s × √3/2.
- Packing efficiency refers to the proportion of bed area covered by plant canopy circles (assuming canopy diameter equals spacing).
- This calculator assumes flat, rectangular beds with uniform soil and no obstacles.
- Recommended spacings by plant type: lettuce 6–8 in, tomatoes 18–24 in, carrots 3–4 in, peppers 12–18 in, squash 24–36 in (per University of Minnesota Extension).
- Reference: Bartholomew, M. (2013). All New Square Foot Gardening. Cool Springs Press.
- Reference: University of Minnesota Extension — Vegetable Garden Spacing Guidelines.