Square foot gardening: how many plants fit in each square

Square foot gardening divides a bed into a grid of 30 cm squares and puts 1, 4, 9 or 16 plants in each, depending on how big the crop gets. A tomato or cabbage takes a whole square, lettuces go four to a square, beetroot nine, and carrots or radishes sixteen.

The idea was popularised by Mel Bartholomew in the early 1980s as a way to grow more in less space with less weeding. It suits raised beds, small gardens and anyone who finds long rows wasteful.

How the 1, 4, 9, 16 system works

Each number is simply a grid inside the square:

Plants per square	Grid	Spacing between plants	Typical crops
1	One in the centre	30 cm	Tomato, pepper, cabbage, broccoli
4	2 by 2	15 cm	Lettuce, chard, parsley, sweetcorn
9	3 by 3	10 cm	Beetroot, spinach, dwarf French beans, garlic
16	4 by 4	7.5 cm	Carrots, radishes, onions, spring onions

To mark out the holes, press a finger into the compost to make the grid: one hole in the middle for 1, the middle of each quarter for 4, and so on. A few crops don’t fit the pattern. Peas go in at 8 per square, usually as two short rows of four beside a net, and the largest plants such as courgettes spread over several squares.

Square foot gardening spacing chart

These numbers come from VegLog’s crop library, which uses square foot gardening guidance alongside conventional row spacings.

Crop	Plants per square	Notes
Carrot	16	Needs deep, stone-free compost
Radish	16	Ready in a few weeks, good for gaps
Onion	16	From sets or seedlings
Spring onion	16	Sow a pinch per hole if you like
Salad leaves	16	Cut-and-come-again
Beetroot	9	Each “seed” is a cluster, so thin to one
Parsnip	9	In the bed for most of the year
Garlic	9	Plant cloves in autumn
Leek	9	Long season, plan the square in advance
Spinach	9
Turnip	9
Dwarf French bean	9	Climbing types go at the back on supports
Coriander	9
Pea	8	Two rows of four, with netting
Lettuce	4	Hearting types; loose-leaf can go closer
Chard	4	Crops for months from one sowing
Broad bean	4	Stake taller varieties
Runner bean	4	Back of the bed on canes
Sweetcorn	4	Plant in a block of squares for pollination
Shallot	4
Basil	4
Parsley	4
Rocket	4
Kohlrabi	4
Strawberry	4	Better in a permanent bed of their own
French marigold	4	Fill odd corners near tomatoes
Cucumber	2	Trained up a trellis
Tomato	1	Cordon types, staked and side-shooted
Sweet pepper	1
Chilli	1
Aubergine	1
Potato	1	Needs depth for earthing up
Cabbage	1
Broccoli	1
Cauliflower	1
Kale	1
Brussels sprout	1	Tall, needs firm planting
Celeriac	1
Melon	1 per 2 squares	Best trained up a frame
Courgette	1 per 4 squares	Spreads well beyond its square
Purple sprouting broccoli	1 per 4 squares	In the ground for about a year
Squash and pumpkin	1 per 9 squares	Or train trailing types over the edge of the bed

These are fair numbers for most varieties, but the label on the seed packet wins if it says a variety is extra large or compact.

Metric squares for UK growers

A foot is 30.5 cm, and most UK and European growers just use 30 cm squares. The difference is too small to matter to the plants. A 1.2 m by 1.2 m bed gives a neat 4 by 4 grid of 16 squares, and a 1.2 m by 2.4 m bed gives 32.

Keep beds no wider than about 1.2 m so you can reach the middle from either side without stepping on the soil. Mark the grid with string, thin battens or canes laid across the top. It sounds fussy, but the grid is what stops you sowing too thickly.

Where to put tall crops

Put tall crops on the north side of the bed so they don’t shade everything else. In the northern hemisphere the sun comes from the south, so runner beans, climbing French beans, cucumbers on trellis, peas, tomatoes and sweetcorn all belong along the north edge. Runner beans can reach about 2.5 m, and tomatoes and sweetcorn about 1.8 m, so they cast a long shadow.

A trellis or net along that edge turns one row of squares into a vertical growing space. Cucumbers, climbing beans, peas and small squashes can all be trained up it, freeing the rest of the bed for lower crops.

Leave the south side for low crops such as lettuce, carrots, radishes and herbs.

Succession sowing square by square

One of the best things about the grid is that each square works on its own. When you harvest a square, you can refill it straight away instead of waiting for a whole row to finish.

1. Clear the old plants and roots.
2. Add a trowel or two of compost and mix it in lightly.
3. Sow or plant something from a different family, so a square of radishes isn’t followed by more brassicas.
4. Sow small amounts often: one square of lettuce every two or three weeks gives a steady supply instead of a glut.

Quick crops such as radishes, rocket and salad leaves are useful fillers between slower ones. A square of early carrots can be followed by lettuce or spinach for autumn, and a square of garlic lifted in summer can take a sowing of beetroot or salad.

Common mistakes

• Shallow beds for root crops. Carrots and parsnips fork when they hit hard soil. Give them at least 30 cm of loose compost.
• Forgetting how big plants get. A courgette in a single square will smother its neighbours by midsummer.
• Putting the trellis on the wrong side. On the south side it shades the whole bed.
• Letting a full bed go dry. A densely planted square foot bed uses a lot of water in summer, and raised beds drain fast. Check the compost with a finger every few days in warm weather.