How to Grow Carrots From Seed

Carrots are cool-season roots that are sown directly in the garden, not started indoors. Sow the first crop 2 to 3 weeks before your last spring frost, once the soil can be worked, and continue sowing small batches every few weeks for a steady supply. For a fall harvest, sow again about 10 to 12 weeks before your first fall frost. Carrots grow best when temperatures sit between 60 and 70F, and a light fall frost actually makes them sweeter.

Loosen the bed at least 8 to 10 inches deep and rake out every stone and clod so roots grow straight. Sow seeds about a quarter inch deep, roughly half an inch apart, in rows 6 to 8 inches apart, then cover lightly and water gently. Because the seed is tiny and slow, keep the surface moist for the full 14 to 21 days it takes to germinate, covering the row with a board or light mulch to stop it drying out. Do not add fresh manure, which causes forked roots, and thin seedlings to 2 to 3 inches apart once they are a couple of inches tall.

Carrots reward steady, even moisture and a light hand with feeding. Water deeply about an inch a week so roots grow long and never woody, and mulch to keep the soil cool and hold moisture. Skip high-nitrogen fertilizer, which grows lush tops and hairy, forked roots instead of clean carrots; a low-nitrogen feed or compost is plenty. Keep the shoulders covered with soil or mulch as they push up, so they do not turn green and bitter, and thin a second time so each carrot has room to size up.

Carrots do best alongside plants that confuse or trap their pests and draw in helpful insects. Onions, leeks, lettuce, radishes, and aromatic herbs all pair well, while dill and mature tomatoes are best kept at a distance. These three companions are especially easy to add in one click:

Carrots are ready to pull about 55 to 75 days after sowing, once the shoulders are the size you want, though flavor is sweetest when they reach full size. Loosen the soil beside each root with a fork before pulling, so the carrot does not snap off in the ground. In mild areas you can leave carrots in the soil and harvest through winter under a thick mulch, digging as needed.

Carrots are one of the most versatile roots in the kitchen, good raw, roasted, steamed, juiced, or grated into cakes and slaws. Different colors bring their own character: orange types are the all-purpose classic, while purple, red, yellow, and white carrots add color to a plate and a little variety in flavor. The feathery tops are edible too, chopped into soups or made into pesto, and carrots store for months in a cool spot.

• Poor germination: the seed is slow and dries out easily. Keep the surface moist for 14 to 21 days and cover the row with a board or light mulch until sprouts appear.
• Forked or twisted roots: caused by stones, heavy soil, or fresh manure. Loosen the bed deeply, remove rocks, and use only well-rotted compost.
• Thin, stunted carrots: usually from skipping thinning. Thin seedlings to 2 to 3 inches apart so each root has room to size up.
• Green shoulders: the tops of roots turn green and bitter when exposed to light. Mound soil or mulch over the shoulders as they push up.
• Carrot rust fly: maggots tunnel into roots. Use a floating row cover, avoid crushing the foliage, and interplant with onions or aromatic herbs to mask the scent.