Vegetable Garden Spacing Calculator
Set your bed dimensions, pick your vegetables, and see how many plants fit with a visual grid layout. Companion planting compatibility checked automatically. 25 vegetables. Nothing uploaded.
Bed Dimensions
Vegetables
Plant Counts
Add vegetables from the list.
Companion Planting
Bed Layout (top view)
Learn more: plant spacing and companion planting
How the plant count is worked out
The calculator divides the bed length and the bed width by the plant's spacing and rounds each down to a whole number. That gives a grid of columns and rows, and the plant count is columns times rows. A 240 cm by 120 cm bed holds 4 x 2 = 8 tomatoes at 60 cm, or 30 x 15 = 450 carrots at 8 cm.
Why spacing varies so much
The calculator's spacings run from 8 cm for carrot, radish and pea up to 90 cm for courgette, a gap of more than ten times. It reflects how much root space and canopy each plant needs at maturity. Packing plants closer than that makes them compete for light, water and nutrients, which can cut yield per plant faster than it adds plants to the bed.
Which companion claims hold up
Laidback Gardener's article on companion planting and science says tomatoes grown with and without basil were compared in blind taste tests over three years and showed no difference. It says fennel roots release substances that slow the growth of neighbors, particularly tomatoes, beans and most legumes, and it lists marigolds against nematodes among the documented examples.
The calculator's "keep apart" warnings come from its own plant list, for example onion with bean or pea, and kale with tomato. They are rules of thumb, so treat them as a prompt to check, not a result of testing.
FAQ
Does closer spacing always mean a higher yield?
No. Tighter than a plant's mature size means more competition for light, water and root space, which can lower the yield from each plant by more than the extra plants add.
Is companion planting backed by science?
Some of it. Fennel's effect on neighbors and marigolds against nematodes are described as documented, while the basil and tomato flavor idea did not hold up in blind tests. Treat the pairings as a mix of tested effects and tradition.
Why does the calculator flag some pairings?
Some plants slow the growth of nearby plants or compete hard for the same nutrients and water. The calculator lists those pairs so you can keep them apart in the layout.