Plant spacing calculator
How many plants fit in the bed?
Choose what you are growing and see the grid you would actually plant: how many across, how many down, and the space left over at the edges.
The same bed, two very different answers
The identical 4 × 8 ft bed holds:
A tomato plant given 12 in instead of 24 in does not produce twice as much. It produces less, because airflow drops, disease spreads faster, and competing roots limit fruit size. The spacing figures here are conventional recommendations, not a standard, and they assume you are growing for yield rather than for a dense ornamental look.
Spacing and support are one decision
Cucumbers and pole beans need a fraction of the ground space when they are grown up rather than along. A cucumber at 12 in on a vertical trellis occupies about a square foot of bed; left to sprawl it needs six or more. If you are short of space, the answer is usually a trellis rather than tighter spacing.
Where the grid model breaks down
A square grid assumes an even canopy. Real beds are interplanted: quick radishes between slow brassicas, lettuce under taller plants that shade it in summer. It also assumes you can reach everything, which is why beds wider than 4 ft get a path or a plank. The count is what the bed can carry without competition; interplanting is extra, not planned.