How far apart to plant carrots
Virginia Cooperative Extension and Colorado State University Extension thin carrots to 1.5 to 2 inches apart in the row, with rows 6 to 12 inches apart. In a raised bed where you plant in every direction, 2 to 3 inches each way works, and the square foot method from the UC Master Gardeners guide fits 16 carrots per square foot, one every 3 inches.
Carrots are always sown straight into the bed, so the spacing is the distance you thin to, not the distance you sow at. Tiny seed is hard to place exactly; sow thinly, then pull the extras once the seedlings are up.
How many carrots fit a raised bed
| Bed | 2.5 in each way (square) | Square foot method (16 per sq ft) |
|---|---|---|
| 4 × 4 ft | 361 | 256 |
| 4 × 8 ft | 722 | 512 |
| 3 × 6 ft | 392 | 288 |
| 4 × 12 ft | 1,083 | 768 |
The first column is what the calculator shows by default: the middle of the 2 to 3 inch bed range, with half a spacing kept clear along every edge. At 2.5 inches a carrot gets about 6 square inches of ground, against 9 in the square foot method, so the bed count runs higher. Use the square foot column if you grow thick, long varieties or want roots with room to size up.
In rows, a 10 ft row thinned to 2 inches holds 60 carrots and a 25 ft row holds 150.
Carrots per square foot
Carrots per bed = bed area in sq ft × 16
Sixteen per square is a 4 by 4 grid, 3 inches between plants each way. That is the figure most square foot charts use for carrots, and the calculator's square foot view fills each square that way. A 4 × 8 ft bed has 32 squares, so 32 × 16 = 512.
How deep to sow and when
Sow carrot seed ¼ to ½ inch deep. Utah State University Extension says carrots come up slowly, in 14 to 21 days, and a crusted surface can stop the seedlings from breaking through. It covers the seed with compost or fine sand instead of soil, and suggests sowing a few radishes in the carrot row: they ease the crusting problem and mark where the row is.
Spring sowing starts 2 to 3 weeks before the last frost, since carrot seed germinates in soil as cool as 40°F (Oregon State University Extension). Utah State sows again every 4 weeks for a steady supply. The dates for your ZIP code are on the carrot planting dates page.
Carrots in containers
Carrots need depth more than width: Colorado State and Virginia Tech call for at least 12 inches of soil. Texas A&M AgriLife's container guide (E-545) lists a 1 gallon pot for 2 to 3 carrot plants, with the pot 2 inches deeper than the root you expect.
Using the calculator
The calculator starts on carrots in a 4 × 8 ft bed at 2.5 inches, square pattern. Switch to Rows to use 2 inches in the row and a between-row spacing, or to Triangular to fit a few more in a wide bed. The unit toggle shows centimetres; 2 inches is about 5 cm.
To share the bed with other crops, lay it out in the square foot gardening calculator or the raised bed planner.