Spacing Is Simple Division

Plants per row = usable length ÷ spacing + 1, rounded down — the +1 because a plant goes in each corner. Rows work the same on the width axis, and the border inset shrinks both usable dimensions. For a 10×5 ft bed at 12-inch spacing with a 6-inch inset, that's 9 plants per row and 4 rows: 36 plants.

The Staggered Bonus

Shifting alternate rows half a spacing creates the hexagonal packing pattern, which is the densest way to arrange circles in a plane — about 15.5% more plants than a square grid. It's the difference between 36 and 42 plants in the same bed. The trade-off: staggered beds are harder to weed in straight lines.

Spacing Rules Are Root Rules

The distance between plants is really about how much soil each root system needs and how much air each canopy requires. Seed-packet spacing exists because plants packed too tightly compete for water and light and breed fungal disease. When in doubt, round spacing up — crowded plants yield less than well-spaced ones.