How the garden spacing calculator works
The calculator trims your bed by the border allowance on every side, then fits rows across the planting area at your row spacing and plants along each row at your plant spacing. Rows = floor(across ÷ row spacing) + 1, and plants per row = floor(row length ÷ plant spacing) + 1. Multiply the two for positions per bed, then by the number of beds.
Plant spacing vs. row spacing
Plant spacing is the gap between plants in the same row; it controls how much light, water and nutrient each plant gets. Row spacing is the gap between rows; it sets your working space for weeding, harvesting and airflow. Tight plant spacing with wide rows suits root crops and carrots. Wide spacing on both axes suits sprawling crops such as squash.
Square (grid) planting
Grid planting uses one spacing in both directions, so each plant owns a square of soil. It is popular in raised beds because there are no permanent paths between rows and every bit of soil is used. Choose Grid spacing above and the calculator uses your plant spacing for both axes. Grids work best in beds narrow enough to reach across, commonly about 1.2 m (4 ft).
Reading seed packet recommendations
Packets usually list sowing depth, final spacing between plants and spacing between rows. If a packet gives a range (for example 20–30 cm), the low end gives more plants per bed and the high end gives larger individual plants and better airflow. Try both values in the calculator to compare plant counts.
Sowing extra seed and thinning
Not every seed germinates, so many gardeners sow two or three seeds per position and thin to the strongest seedling. Thin by snipping at soil level rather than pulling, which protects neighbouring roots. Enter your seeds-per-position number to estimate the seed you need to buy; thinned seedlings of some crops can be transplanted or eaten.
Practical garden layout tips
- Run rows north to south where you can, so plants share morning and afternoon sun.
- Keep beds reachable from the paths: about 1.2 m wide, or 0.9 m if only one side is accessible.
- Put tall crops (tomatoes, pole beans) on the north side so they don’t shade shorter plants.
- Leave a border allowance next to walls or fences for airflow and watering access.
- Round the result down if you want breathing room, and keep a few spare seedlings for gaps.
Example spacing ranges (starting points only)
These are rough, commonly quoted ranges. Always check your own packet, because cultivars differ.
| Crop | Between plants | Between rows |
|---|---|---|
| Radish | 2.5–5 cm (1–2 in) | 15–25 cm (6–10 in) |
| Carrot | 3–7 cm (1–3 in) | 20–30 cm (8–12 in) |
| Lettuce (head) | 20–30 cm (8–12 in) | 25–35 cm (10–14 in) |
| Bush beans | 7–10 cm (3–4 in) | 45–60 cm (18–24 in) |
| Tomato | 45–60 cm (18–24 in) | 75–100 cm (30–40 in) |
| Summer squash | 60–90 cm (24–36 in) | 90–120 cm (36–48 in) |