Carrots belong to the Apiaceae family and are really an easy vegetable to grow (Fig. 6.6). They are adaptable and tolerant of poor gardening techniques, so they should be grown in most every vegetable garden. Carrots are a cool-season crop and prefer temperatures for growing in the 45°–75°F range. When planted in the early autumn and then harvested during the winter and/or early spring the following year, carrots will have an outstanding sweet flavor that you cannot find at most supermarkets. Some varieties work best for this purpose, and the placement of an organic mulch over the soil surface will also help to protect roots from cold winter temperatures. Any home vegetable gardener in temperate climate areas can have carrots year-round out of the garden if they just know how to manage these plants during cold weather.
The soil type or condition of the soil is probably the most important factor when considering growing carrots in the garden. Carrots grow poorly in heavy soils. Long-rooted varieties may be stunted, forked, or twisted. Growing conditions can often be improved by incorporating organic matter, such as compost, into heavy soils. Although any good garden soil will grow carrots, a deep, loose, and fertile sandy loam or peat soil with good moisture holding capacity and high organic matter will grow the straightest and smoothest roots. The soil should be tilled deeply and raised beds tend to work best. Compacted soil conditions will cause malformed or misshapen roots.
Carrots are light nutrient feeders, so limited sidedress fertilizer applications are typically needed. However, nitrogen applications should not be made close to harvest or once they are about three-fourths their mature size. Late applications of nitrogen will also cause roots to split. So, before planting, it is recommended to apply about 1 to 2 lbs of complete fertilizer containing about 10% N per 100 ft2 of row and that’s really all the fertilizer you need to apply for the entire season.
Crusting of the soil surface and dry soil conditions may result in poor germination. This is particularly true with late-summer plantings. Crusting may be prevented by lightly covering the seeded row with moist compost. During dry weather conditions, provide a source of water daily to the seeded carrots to promote germination.
For spring planting, seeds should be planted 2 to 4 weeks before last expected frost and for fall planting, seeds need to be planted approximately 2 months before first expected frost. Sow carrot seeds at a depth of ¼ to ½ inch. For a continuous harvest, succession planting should be used for carrots and additional plantings should be made every 3 to 4 weeks. Space rows 18 to 24 inches apart. Thin seedlings within a few weeks of germination, and after thinning, seedlings should be spaced 2 to 3 inches apart. The soil should be kept moist to prevent soil crusting before seedlings emerge. Carrots usually mature in 50 to 70 days after seeding. Carrots can, however, be harvested at any point that the roots are large enough to eat. Carrot crowns should be covered with soil to prevent greening of crowns, which cause roots to develop a bitter taste. Carrots are usually dug at any time after they obtain a good orange color and are greater than 1 inch in diameter. Generally, the best harvest period lasts about 3 weeks (or 5 to 7 weeks during cooler, fall weather).
Carrots need approximately 1 inch of water every week from rain or supplemental irrigation. Adequate water is essential for root enlargement. Watering should be reduced when carrots are three-fourths their mature size to reduce the chance of root splitting.
Generally, carrots do not have many insect or disease problems. However, problematic insects include the carrot rust fly (maggots chew roots and will causing plant stunting), the carrot weevil (will defoliate plants, and larvae tunnel into carrots), the parsley worm (will totally defoliate plants), and the wireworm (larvae chew and bore into roots). Disease problems include root-knot nematodes (cause plant stunting, yellowing of foliage, and galls on roots), damping-off of young seedlings (usually caused by various species of Pythium or Rhizoctona solani), and leaf blights (species of Alternaria and Cercospora can be important pathogens).
Weed control can be a major issue when growing carrots. It is best to control weeds when they are still in the seedling stage and this can be achieved with frequent, shallow cultivating (hoeing) or pulling weeds by hand in the immediate vicinity of the carrots. When the carrots are well established, the application of a mulch between the rows will help control weeds and conserve soil moisture.
There are numerous carrot varieties available to home gardeners. The main differences between varieties are the shape and size of the root. However, a few varieties have unusually colored roots. Carrot roots can be long and tapered, cylindrical, or even roundish. Most carrots are orange, although yellow, red, and purple varieties are also available. Suggested carrot varieties for home gardeners include:
‘Danvers Half-Long’ (75 days; uniform, 7- to 8-inch-long roots tapered to very blunt end).
‘Danvers 126’ (75 days; smooth roots; foliage can withstand hot temperatures)
‘Imperator 58’ (68 days; smooth, fine-grained, long, tapered roots; standard long, thin type of carrot)
‘Little Finger’ (65 days; baby type with tiny tender roots; ½-inch-thick and 5-inchlong roots; golden orange; sweet and crisp)
‘Purple Haze’ (70 days; novelty type; 2006 AAS winner and first Imperator-shaped purple carrot; 10- to 12-inch-long purple-skinned roots with vivid orange centers)
‘Red-Cored Chantenay’ (70 days; heavy yielder; short, thick roots, broad at the shoulder, tapered to blunt tip)
‘Royal Chantenay’ (70 days; broad-shouldered, tapered roots; bright orange)
‘Scarlet Nantes’ (70 days; 6-inch-long bright-orange roots that are slightly tapered; standard for high-quality carrots)
‘Short ’n Sweet’ (68 days; baby type with sweet flavor; 4-inch roots, broad at shoulder, tapered to a point; good for heavy or poor soil)
‘Tendersweet’ (75 days; long, tapered roots; nice orange color; coreless)
‘Thumbelina’ (60 days; 1992 AAS winner; round roots; good for planting in containers and in heavy, shallow, or rocky soil)
Carrots are a nutritious, versatile vegetable, and provide an excellent source of vitamin A. They are rich in carotene (the source of vitamin A) and high in fiber and sugar content. Carrots can be shredded, chopped, juiced, or cooked whole. They are delicious raw, roasted, boiled, steamed, stir-fried, and grilled, and they team up beautifully with almost any vegetable. Carrots boost the nutritional value of soups, stews, salads, and many other foods. Mature carrots can be stored for several months at a temperature of 32°F and relative humidity of greater than 95%.