The carrot is one of our most common and widely grown vegetables. It grows best at mean temperatures between 600-700° F. Prolonged higher temperatures tend to produce shorter, non-blunt roots, while temperatures below 50° F. tend to make roots longer, more slender and paler in color.
California, Texas, Arizona, and New Mexico are the important commercial production areas for the winter and spring crop. Most of the northern states have large acreages for summer and fall harvest, used fresh and for processing and freezing.
Seedsmen list a large number of varieties but only a few of these listed sorts are important. Those having long, cylindrical and smooth shape include ‘Imperator’, ‘Gold Pak’, and ‘Nantes Half Long’. Other standard varieties include ‘Red Cored Chantenay’ and ‘Danvers Half Long’.
Carrots, like beets, grow best in a deep, loose sandy loam, loam or muck soil that is high infertility and water-holding capacity. Soil preparation and fertilizer recommendations outlined for beets apply equally well for carrots. Note should be made to the effect that strawy manure or raw compost should not be used because its use just prior to planting will tend to produce knobby, misshapen roots with many fibrous side rootlets.
Carrot Planting and Care
Carrot seed is slow to germinate and, there-fore, a few quick germinating radish seeds are frequently scattered in the drill to mark the rows and thus permit earlier cultivation. Sow the seed in drills in. in depth at the rate of oz. per too ft. of row. As soon as the plants reach a height of 2-3 in., thin to a spacing of 11-12 in. Space the rows 12-15 in. apart. The seed may be planted as soon as the ground can be prepared, and for continuous supply make a planting every 3 weeks until Aug. 1. This applies to the northern states. Shallow cultivation is important starting as soon as possible after planting. Commercial growers use a petroleum product Stoddard Solvent to control weeds in carrots. The use of herbicides and chemicals for weed control is, however, not recommended in the small home garden.
Carrots are most tender and sweet if harvested before the roots reach their mature size or for the long types and the shorter chantenay types. Carrots may be harvested in the late fall and stored in the same manner as recommended for beets.
Carrot Insects and Diseases
The carrot caterpillar is green banded with black and yellow markings and up to 2 in. long.
It seldom does much damage. The carrot rust fly is becoming a serious problem in some areas. The yellowish-white, legless and up to in. long larvae tunnels into the outer fleshy root. Control involves the use of a diazinon dust applied at the rate of 2 lbs. per 2 sq. ft. of soil surface. Apply to the soil before planting and then work it thoroughly into the upper 6 in. Leaf blight and carrot yellows are diseases of lesser importance that can cause some damage. Spray with Maneb. Carrot yellows, a virus, is spread by the 6-spotted leaf hopper. To control the hopper use a 4% malathion dust. Three to four applications at 7-10-day intervals starting as soon as the first leaf hoppers appear.