How It Works
This calculator supports two layout methods. Both assume you plant from the edge of the bed inward, centering the first plant at half-spacing from the border.
Grid Layout
The simplest approach: equal rows and columns. Convert your bed dimensions to inches, divide by plant spacing, and add 1 to include the first plant at the starting edge.
- Plants per row = floor(bed length in inches / spacing) + 1
- Number of rows = floor(bed width in inches / spacing) + 1
- Total plants= plants per row × number of rows
Grid is easy to plant, weed, and harvest. Drip irrigation lines follow straight rows naturally.
Staggered (Offset) Layout
Alternating rows are shifted by half the spacing distance. This hexagonal packing reduces wasted space between circles of root zones, fitting roughly 15% more plants in the same area.
- Row spacing= plant spacing × 0.866 (the square root of 3, divided by 2)
- Even rows have the full count; odd rows may lose one plant at the edge due to the offset.
Staggered works best for leafy greens, herbs, and root vegetables where you want maximum density. Avoid it for large vining crops (squash, melons) that need clear row access.
Vegetable Spacing Guide
Use this table as a quick reference when planning your garden beds. Spacing refers to the distance between plant centers — not edge to edge.
| Vegetable | Spacing (in) | Planting Depth | Sun | Days to Harvest |
|---|---|---|---|---|
| Tomatoes | 24 | 1/4" | Full sun | 60–85 |
| Peppers | 18 | 1/4" | Full sun | 60–90 |
| Lettuce | 6 | 1/8" | Part shade OK | 30–60 |
| Carrots | 3 | 1/4" | Full sun | 70–80 |
| Squash / Zucchini | 36 | 1" | Full sun | 50–65 |
| Beans (bush) | 6 | 1" | Full sun | 50–60 |
| Cucumbers | 12 | 1/2" | Full sun | 50–70 |
| Basil | 8 | 1/4" | Full sun | 50–75 |
| Parsley | 8 | 1/4" | Part shade OK | 70–90 |
| Onions | 4 | 1" | Full sun | 90–120 |
| Broccoli | 18 | 1/4" | Full sun | 80–100 |
| Kale | 18 | 1/4" | Full to part sun | 55–75 |
| Spinach | 6 | 1/2" | Part shade OK | 37–45 |
| Radishes | 2 | 1/2" | Full to part sun | 22–30 |
| Peas | 3 | 1" | Full to part sun | 60–70 |
| Eggplant | 24 | 1/4" | Full sun | 70–85 |
| Cauliflower | 18 | 1/4" | Full sun | 55–80 |
| Cilantro | 6 | 1/4" | Part shade OK | 45–70 |
Square Foot Gardening
The Square Foot Gardening (SFG) method, popularized by Mel Bartholomew, divides raised beds into 1×1 foot squares. Each square holds a fixed number of plants based on spacing requirements. It is the simplest way to plan a small garden without a calculator.
| Plants per Square Foot | Spacing | Examples |
|---|---|---|
| 16 | 3" | Carrots, radishes, peas |
| 9 | 4" | Onions, beets, turnips |
| 4 | 6" | Lettuce, beans, spinach |
| 2 | 8" | Basil, parsley, cilantro |
| 1 | 12" | Cucumbers, peppers (compact), dill |
| 1 per 2 sq ft | 18" | Broccoli, kale, cauliflower, peppers |
| 1 per 4 sq ft | 24" | Tomatoes, eggplant |
| 1 per 9 sq ft | 36" | Squash, melons, pumpkins |
SFG works best in raised beds 4×4 ft or 4×8 ft. Use string or thin strips of wood to divide the bed into a visible grid. The method eliminates row spacing waste entirely — every inch of soil grows food.
FAQ
Does staggered layout actually produce more plants?
Yes. Hexagonal packing (the math behind staggered rows) is the most efficient way to fill a plane with equal circles. In practice, you get about 15% more plants per bed compared to a straight grid at the same spacing. The difference is most noticeable with tightly spaced crops like lettuce, carrots, and radishes.
Should I measure spacing from plant center or from the edge of the foliage?
Always measure from center to center. Published spacing numbers already account for the mature canopy width of each plant. If a tomato says 24-inch spacing, that means 24 inches between the center of one stem and the center of the next.
Can I plant closer than the recommended spacing?
You can, but yields per plant drop. Tighter spacing increases competition for light, water, and nutrients. It can also reduce airflow, which promotes fungal diseases. If you want to push density, try a 10–15% reduction at most, and make sure your soil is amended with extra compost to compensate.
How do I account for trellised or vertical plants?
Trellised crops (tomatoes, cucumbers, pole beans) can be spaced more tightly in-row because the foliage grows up, not out. A trellised tomato may do fine at 18 inches instead of 24. Adjust the spacing input in the calculator accordingly — but keep the trellis row on the north side so it does not shade shorter plants.
Related Tools
- Soil Volume Calculator — figure out how much soil your beds need before planting.
- Raised Bed Cost Calculator — estimate lumber and hardware costs for a new raised bed.
- How to Fill a Raised Bed — layering methods that save money on soil.