How Many Carrots, Onions and Garlic Fit in a Bed? Close-Spaced Crops in Numbers
Tomatoes are counted in ones and twos. Carrots, onions and garlic are counted in hundreds. Because these crops are spaced only a few inches apart, small changes in spacing or bed size make a big difference to how many seeds, sets or cloves you need, and to how much you harvest.
The Plant Spacing Calculator handles the counting. Enter the bed length and width in feet, choose the crop, and pick a square or triangular pattern. The presets for these crops are: carrot and radish 3 inches, onion, garlic and beet 4 inches. If your seed packet says something different, choose Custom spacing and enter that figure in inches.
How many per square foot
The simplest way to think about close-spaced crops is plants per square foot. On a square grid the calculator gives:
| Crop | Spacing | In 1 sq ft |
|---|---|---|
| Carrot, radish | 3 in | 16 (4 rows of 4) |
| Onion, garlic, beet | 4 in | 9 (3 rows of 3) |
These are the same densities used in square-foot gardening grids, which is a useful cross-check: if you garden in 1 foot squares, one square holds 16 carrots or 9 onions.
A full 4 x 8 bed
Scale up to a standard 4 by 8 foot raised bed planted with a single crop:
| Crop | Rows x per row | Total |
|---|---|---|
| Carrot (3 in) | 16 x 32 | 512 |
| Radish (3 in) | 16 x 32 | 512 |
| Onion (4 in) | 12 x 24 | 288 |
| Garlic (4 in) | 12 x 24 | 288 |
| Beet (4 in) | 12 x 24 | 288 |
Few households want 512 carrots at once, which is why these crops are usually given part of a bed, or sown in batches a couple of weeks apart. A single 10 foot row of carrots (enter 10 feet long and 0.25 feet wide) holds 40 at 3 inches.
A smaller 3 x 6 bed
A 3 by 6 foot bed is a common size for a first garden or a narrow side yard:
| Crop and pattern | Rows x per row | Total |
|---|---|---|
| Carrot, 3 in, square | 12 x 24 | 288 |
| Onion, 4 in, square | 9 x 18 | 162 |
| Garlic, 4 in, square | 9 x 18 | 162 |
| Garlic, 4 in, triangular | 10 rows, 18 / 17 offset | 175 |
The triangular pattern adds one row of garlic here because the offset rows sit 0.866 times the spacing apart. Every other row is shifted half a space along, so in this bed the five shifted rows each hold 17 instead of 18; the calculator counts that, which is why the gain is 13 cloves rather than a full row of 18. For some crops and bed sizes the shifted rows cost more than the extra row gains, and triangular comes out lower than square. Our guide to square and triangular spacing shows how to check.
The spacing you choose changes the answer a lot
Seed packets and growing guides give a range for these crops, and the choice is a trade between number and size. Running the 3 x 6 bed with custom spacings:
- Garlic at 6 inches instead of 4: 72 cloves instead of 162. Wider spacing is often recommended for larger heads.
- Onions at 3 inches instead of 4: 288 instead of 162. Closer onions are smaller, which suits pickling or harvesting some early as green onions.
- Carrots at 2 inches instead of 3: 648 instead of 288. Closer carrots stay slimmer and compete harder for water.
Because these spacings are so small, a one inch change can more than double the count. Decide what size you want to harvest first, then set the spacing.
Turning the count into what to buy
Carrots and radishes: seed, then thin
Carrot and radish seed is tiny and germinates unevenly, so it is sown more thickly than the final spacing and thinned once seedlings are up. The calculator's count is the number of plants you keep after thinning, not the number of seeds to sow. Thin carefully when the soil is moist, and use the thinnings in the kitchen only if you know they are your carrots (see the safety note below).
Onions: sets, transplants or seed
Onion sets and transplants are planted at the final spacing, so the calculator's count is roughly what to buy, plus a few spares. Sets are often sold by weight, so the number in a bag varies; check the label or count a handful.
Garlic: count cloves, not heads
Garlic is planted as individual cloves, each of which grows into a new head. The count from the calculator is the number of cloves you need. The number of cloves in a head varies a lot by variety, so break one open before deciding how many heads to buy, and plant the larger outer cloves. Seed garlic sold for planting is a safer choice than supermarket garlic, which may be a variety unsuited to your climate.
Sharing a bed with other crops
If these crops share a bed, the Garden Layout Planner splits the area equally between the crops you choose and counts each. For carrot, onion and garlic in a 4 x 8 bed, each gets 10.7 square feet and the planner returns 170 carrots, 96 onions and 96 garlic. It lists carrot and onion as a traditional good pairing and flags no conflicts.
Two cautions. First, the planner counts by area (square feet divided by the spacing squared), and labels its counts an area-based estimate. That can be a little higher than what fits in whole rows, so check each patch in the spacing calculator before buying. Second, its companion table does not include every crop. Garlic has no entry of its own (although beans list it as a crop to keep apart), and the planner says so under "No companion data", so read its silence on garlic as missing data rather than an all-clear. Companion pairings are garden tradition rather than guarantees; treat them as reminders, not rules.
What the calculator does not cover
- Germination and losses. Not every seed comes up, and slugs, cutworms and birds take seedlings. Sow extra and thin; the count is a target, not a promise.
- Timing. Garlic is usually planted in fall for a summer harvest, while carrots and radishes are sown from spring onward. The Planting Calendar gives carrot sowing dates from your frost dates; it does not schedule garlic.
- Soil depth. Long carrots need loose soil well below the surface; stony or compacted soil gives forked roots whatever the spacing. The Soil Volume Calculator works out how much mix it takes to deepen a bed.
- Varieties. Round carrots, long carrots, bunching onions and storage onions all suit different spacings. Use the custom option with the packet figure.
Safety notes
- Onions, garlic, leeks and chives are toxic to dogs and cats. Keep bags of sets and cloves out of reach, and do not leave trimmings or culls where pets can eat them.
- Know your seedlings. The carrot family includes poisonous wild plants such as poison hemlock, whose seedlings can come up in disturbed soil and look similar to carrot seedlings. Sow in rows or marked patches so you know what you planted, and never eat a plant you have not positively identified.
- Wear gloves when working soil and wash your hands before eating. Keep your tetanus vaccination up to date.