Work out how many plants fit in a bed, based on the bed's length and width, and the desired plant and row spacing.
The calculator works out the number of plants along the bed's length, and the number of rows along the width, and multiplies these:
The right plant spacing varies a lot by species and expected size — always check the recommended spacing on the seed packet or plant label for the best result. For example, lettuce typically needs 20–30 cm spacing, while larger plants like cabbage or squash need 40–60 cm or more.
Because the first plant or row is placed right at the edge of the bed (distance 0), and the rest are spaced out from there. If you just divide the bed length by the plant spacing without adding 1, you lose the space for the very first plant in the row.
Not necessarily — it depends on the plant species and how you're growing. Many vegetables do well with a square or rectangular pattern with equal spacing both ways, while others (like rows of potatoes) often have wider row spacing than plant spacing within the row.
Overly dense planting creates competition for light, water and nutrients, which can produce smaller, weaker plants and increased risk of fungal disease due to poorer air circulation. Always follow the recommended spacing for the species you're growing.