Carrot is a hardy, cool-season biennial that is grown for the thickened root it produces in its first growing season. Although carrots can endure summer heat in many areas, they grow best when planted in early spring. Midsummer plantings, that mature quickly in cool fall weather, produce tender, sweet "baby" carrots that are much prized. Carrots are eaten both raw and cooked and they can be stored for winter use. They are rich in carotene (the source of vitamin A) and high in fiber and sugar content.

Care and cultivation
When to plant
Carrots are usually planted with other frost tolerant vegetables as soon as the soil mellows in the spring. They may be planted earlier in gardens with sandy soil. The soil should be plowed and prepared to a depth of 8 to 9 inches to allow full development of the carrot roots and the seedbed should be worked uniformly to break up clumps and clods that prevent penetration of the roots. Varieties with extremely long roots (Imperator and Tendersweet) usually are recommended only for home gardens with deep, sandy soil. Excess organic debris worked into the soil just before planting also may affect root penetration, causing forked and twisted roots.

Spacing and depth
Plant seeds 1/4 to 1/2 inch deep (no more than two or three seeds per inch) in early spring. Later sowings may be planted 1/2 to 3/4 inch deep when the soil is dryer and warmer. Space rows 12 to 18 inches apart. A single radish seed planted every 6 to 12 inches can mark the row. Germination requires as long as two weeks and the seedlings may not emerge uniformly. If heavy rains occur after sowing, packing the soil surface, no seedlings may emerge. Thin the seedlings when they are about one inch tall to no more than three seedlings per inch for finger carrots; one or two seedlings per inch for carrots that will be harvested young; and one seedling per 1 to 2 inches for larger varieties like Danvers and Chantenay that will be allowed to develop to full size and be harvested mature for canning or freezing.

Care
Carrots germinate best in warm, moist soil. Covering the row with clear polyethylene film warms the soil and conserves moisture. Remove the film immediately when seedlings appear. To assure germination of successive plantings during the late spring and summer months, it may be necessary to supply water by sprinkling. In the heat of summer, some shade may be necessary to keep the tiny seedlings from burning off at the soil line.

Young carrot seedlings are weak and grow slowly. It is essential to keep weeds under control for the first few weeks. Cultivate shallowly with a knife blade cultivator or hoe. Deep cultivation may injure the roots.

Harvesting
Carrots can be harvested or "pulled" when the roots are at least 1/2 inch in diameter. Under usual conditions, carrot tops may not be strong enough to withstand actually being pulled from the ground and digging helps to remove the roots without damage. Finger carrots are usually ready to harvest within 50 to 60 days. Other varieties should be allowed to grow until they have reached a diameter of at least 3/4 inch (about 60 to 70 days after planting). They then may be harvested over a 3 to 4 week period. Summer planted carrots may be left in the ground until a killing frost. Some gardeners place a straw mulch over the row so that carrots can be harvested until the ground freezes solid. In many areas, a heavy mulch allows harvest of carrot roots throughout the winter. For carrots to be stored, cut off the tops one inch above the root and place in storage at 32F with high humidity. Carrots may be placed in a refrigerator, buried in lightly moist sand in an underground cellar or stored in the garden in a pit insulated with straw. Under proper storage conditions, carrots keep 4 to 6 months.

Problems
Green crown (top) - This condition is called "sunburning." It causes an off flavor and dark green pieces in the cooked product. Cut away the green portion and use the rest of the root. When the tops are healthy, sunburning can be avoided by pulling a small amount of loose soil up to the row when the roots are swelling (about 40 to 50 days after planting).
Misshapen carrots, with forked and twisted roots - Forking may result from attacks of root-knot nematodes, from stones, from deep and close cultivation or (more frequently) from planting in a soil that was poorly prepared. Twisting and intertwining result from seeding too thickly and inadequate thinning of seedlings.

Carrot varieties
Small, Round
    Orbit (58 days to harvest, good color, few off-types, best harvested at the size of a 50 cent piece)
    Thumbelina (60 days; 1992 AAS winner; round roots; good for planting in containers and in heavy, shallow or rocky soil)

Baby
    Baby Spike (52 days; 3 to 4 inch roots, 1/2 inch thick; excellent internal color; tender; holds small size well)
    Little Finger (65 days; tiny tender roots; 5 inch roots, 1/2 inch thick; golden orange, sweet and crisp)
    Minicor (55 days; slender fingerling carrots; colors early; uniform, cylindrical, blunt tip; good flavor)
    Short 'n Sweet (68 days; rich, sweet flavor; 4 inch roots, broad at shoulder, tapered to a point; good for heavy or poor soil)

Chantenay
    Red-Cored Chantenay (70 days; heavy yield; good flavor; short, thick roots, broad at the shoulder, tapered to blunt tip)
    Royal Chantenay (70 days; broad-shouldered, tapered roots; bright orange; good for heavy or shallow soils)

Danvers
    Danvers Half-Long (75 days; uniform, 7 to 8 inch roots tapered to very blunt end; sweet, tender)
    Danvers 126 (75 days; heavier yield than Danvers; smooth roots; tops withstand heat).

Nantes
    Bolero (hybrid-70 days; 7 to 8 inch roots, uniformly thick, tapered slightly to blunt tip; superior resistance to foliage disease)
    Ingot (hybrid-70 days; 8 inch roots, 1-1/2 inches thick; indistinct core; deep orange color; strong tops; extremely sweet)
    Nantes Coreless (68 days; orange-red; small core, medium top)
    Scarlet Nantes (70 days; bright orange, slightly tapered, 6 inch roots; crisp, tender and flavorful; standard for high quality carrots)
    Sweetness (hybrid-63 days; sweet and crunchy; cylindrical, 6 inch roots, 1 inch thick)
    Touchon (70 days; interior, exterior bright orange; 7 inch roots, nearly coreless)

Imperator
    Avenger (hybrid-70 days; extra fancy; slightly blunt, tapered roots, 9 to 10 inches long)
    Gold Pak (76 days; 8 inch roots, 1-1/2 inches thick; sweet, tender, as coreless as any; good for juice)
    Imperator 58 (68 days; smooth, fine-grained, long, tapered roots; standard long, thin type)
    Legend (hybrid-65 days; high yield; smooth, uniform, 9 to 11 inch roots, 1-1/2 inches at shoulder; tolerant to cracking)
    Orlando Gold (hybrid-78 days; uniform, long, tapered shape; excellent flavor, color; 30 percent more carotene)
    Tendersweet (75 days; long, tapered roots; rich orange color; sweet, coreless)

Novelty
    Belgium White (75 days; mild flavor; long, tapered, white roots; productive, vigorous)