CARROTS

 

by Henry G. Taber and Richard P. Jauron

Department of Horticulture, Iowa State University

Updated: June 1998

Topics:

 Planting  Spacing
 Fertilizing  Varieties
Pest Mangement  Post Harvest Care
 Yield  

 

 

The carrot is a biennial plant. During the first growing season it produces that characteristic foliage and orange root. A large seedstalk will form the second year if left in the ground over the winter.

For detailed informantion, obtain FG-600, titled: Midwest Vegetable Production Guide for Commercial Growers from your local county extension office or Ag Publication and Distribution Center, Printing Bldg., Iowa State University, Ames, IA 50011.

PLANTING

Sow seed at a depth of 1/4 to 1/2 inch any time after March in central Iowa. Make small plantings approximately every 3 weeks for a continuous harvest. Carrots may be planted as late as August 1 for a fall crop.

Poor Germination - Crusting of the soil surface and dry soil conditions may reduce seed germination. This is particularly true of summer plantings. Crusting may be prevented by mulching the seeded row with sawdust, peat moss, or dried grass clippings. Water the seeded row to promote germination.

SPACING

Rows should be spaced 16 to 30 inches apart. Thin to 2 to 3 inches between plants or 20 to 30 plants per foot for slicing/fresh market; 10 to 20 plants per foot for dicing.

FERTILIZING

Don't use fresh manure; misshapen roots may result. In the spring, it is generally safe to apply 2 to 3 lbs of 5-10-5 per 100 sq ft of garden space. Apply P and K according to a soil test report the fall before planting. For further garden fertility practices, obtain Pm-820, Garden Soil Management.

On a commercial basis, lime to maintain a soil pH of 6.0 to 6.8, except for muck soils. Apply N at 60 lb. per acre for mineral soils and P and K according to soil test results. For carrots grown on muck soils with a soil pH greater than 6.0, add 6 lb. of Mn per acre. Carrots grown on mineral soils apply N at 60 lbs./acre preplant and then sidedress 30 to 45 lbs N/acre approximately 4 to 6 weeks after planting.

VARIETIES

Royal Chantenay - slightly tapered, 6 to 7 inches long

Danver's Half Long - cylindrical, 6 to 7 inches long

Dominator - long, tapered root, 8 to 9 inches long

Nantes - half-long, 6 to 8 inches long

Gold Pak - slender, 8 to 9 inches long

Spartan Fancy 80 - good storage qualities

COMMENTS

Misshapen Roots - Carrots do poorly in heavy soils. Long-rooted cultivars may be stunted, twisted or forked in such soils. Growing conditions may be improved by adding humus to heavy soils. Another alternative is to grow the carrots in a raised bed. Do not add large amounts of fresh manure to these soils. The manure will compound the problem. Short-rooted varieties, such as Short'n Sweet, may perform better than the longer-rooted cultivars in heavy, clay soils.

Greenish Carrot - The top of the carrot root will turn green when exposed to sunlight. This area will also have a strong flavor. Cut away the green portion of the root and discard. The remain part of the carrot is fine. Hill soil around the tops of the carrot roots if they become exposed due to soil erosion or cultivation.

PEST MANAGEMENT

Diseases - major problems have been Alternaria and Cercospora leaf blights, white mold and aster yellows.

Insects - predominantly leafhoppers, cutworms, and aphids.

For insect, disease, and weed control obtain a copy of FG-600, titled: Midwest Vegetable Production Guide for Commercial Growers from your local county extension office or Ag Publications Distribution, Printing Bldg., Iowa State University, Ames, IA 50011.

HARVEST

Harvest when roots are 3/4 inch or more in diameter. Approximately 60 to 100 days from planting until harvest.

YIELD

10 lbs per 10 foot row or 15 to 20 tons/acre.

STORAGE

Trim tops for 1/4 to 1/2 inch, then store at 32oF, 90 to 95% RH for 4 to 5 months. Carrots may also be canned, frozen or pickled.

For maximum storage over winter, plant August 1 for a fall crop. Leave them in the ground until just before a heavy frost. Then dig and store.

............Justice for All

The Iowa Cooperative Extension Service's programs and policies are consistent with pertinent federal and state laws and regulations on nondiscrimination regarding race, color, national origin, religion, sex, age, and handicap.


Cooperative Extension Service, Iowa State University of Science and Technology and the United States Department of Agriculture cooperating. Stanley R. Johnson, director, Ames, Iowa. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914.