Rhubarb has a heavy root system and must feed heavily to support the rush of spring growth. The area to be planted should be cultivated deeply and liberal amounts of fertilizer should be incorporated as the soil is worked. A fertilizer such as 12-12-12 should be used at the rate of 3-4 lb. per 100 sq. ft.(3-4 teaspoons per sq. ft.). If possible also cover the area with 2-3” of well-rotted manure and till in. In late fall, use a mixture of composted cow manure and straw as a mulch to help prepare for the following spring. Do not pile compost or any mulch over the crown of the plant. This can lead to crown rot. Each season after harvest, side-dress with 1/3 lb. of ammonium nitrate per 100 sq. ft (1 teaspoon per 3 sq. ft.)
Space plants at least 3 ft. apart in a well-drained rich soil. If drainage is a concern rhubarb can be planted on ridges or mounds. Set crowns 2” deep. Do not set the crowns in direct contact with fresh manure or chemical fertilizers.
Rhubarb grows best and has the best color in cool moist conditions. If soil is dry in established plantings apply 1” of water per week.
Mays Greenhouse ©2010