How to Grow Carrots

Soil is the whole secret to straight roots

Carrots want fertile, well-drained, deep sandy soils rich in organic matter. That depth and looseness is not a nicety — it is what determines whether the root grows straight down or forks and curls. Heavy or rocky soils should be amended and double dug to allow good root development before you sow.

Plant seed just a quarter inch deep, 2 to 3 weeks before the last frost. The seed is small and slow, germinating best when soil sits at 55 to 65°F.

The when-to-plant-carrots calculator localizes that spring window to your frost dates, and if forked or hairy roots are the problem you are chasing, the dedicated forked-carrots diagnostic covers the causes on its own.

Getting the seed up, then thinning

Carrot seed takes 14 to 21 days to emerge — long enough that the top of the soil will crust and dry unless you stay on it. Maintain a uniform, moist soil surface for that entire stretch; a bed that dries out midway germinates unevenly and leaves gaps.

Once seedlings are up, thin them to 2 to 3 inches apart in the row, with rows 12 to 18 inches apart. Crowded carrots stay small and tangled, so thinning is not optional. The carrots-plant-spacing calculator answers the spacing question directly.

Water frequently and uniformly through the season. Alternating wet and dry periods causes the roots to crack, and the how-often-to-water-carrots calculator gives the watering readout for your conditions.

Problems, feeding, and harvest

Two cosmetic problems dominate: forking, which comes from rocky or heavy soil or carrot-fly damage, and green shoulders or poor color, which show up when temperatures climb above 85°F. Cracking traces back to those wet-and-dry swings in watering.

Carrots are light feeders. Side-dress a quarter cup of a nitrogen fertilizer (21-0-0) per 10 feet of row about 6 weeks after emergence; the best-fertilizer-for-carrots calculator covers the feeding decision on its own.

Roots mature in 70 to 100 days from seeding. Pull them once they have sized up — the when-to-harvest-carrots calculator gives the timing readout for your variety.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• Utah State University Extension — Carrots in the Garden — Carrots grow best in fertile, well-drained, deep sandy soils rich in organic matter; heavy soils should be amended and double dug to allow good root development and prevent forking; plant seeds 1/4 inch deep 2-3 weeks before the last frost, germinating best at 55-65°F and requiring 14-21 days to emerge; maintain a uniform and moist soil surface for successful germination; thin to 2-3 inches between plants with rows 12-18 inches apart; roots mature in 70-100 days from seeding; water frequently and uniformly because fluctuations cause root cracking; side-dress 1/4 cup of 21-0-0 per 10 feet of row 6 weeks after emergence; forking occurs in rocky or heavy soils or from carrot fly; temperatures above 85°F cause poor coloring.

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