Broccoli is a cool season vegetable
Growing broccoli in Utah. Broccoli is a cool season vegetable that prefers sunny locations and fertile, well-drained soil. Incorporate plenty of organic matter and a complete fertilizer into the area before planting. Plant seeds 1/4-3/4 inch deep, 2-3 weeks before the last frost in the spring. Thin seedlings or transplant broccoli 12-16 inches apart in the row with rows 2-3 feet apart.
Avoid growing during the heat of summer as yield and quality are reduced. After harvest, side dress with additional nitrogen fertilizer for continued sideshow development. Irrigation should be deep and infrequent. The use of plastic or organic mulches helps conserve water and reduce weed growth. Control insects and diseases throughout the year. Harvest broccoli when the heads are large and compact, but before the flower buds open.
There are many good varieties for growing broccoli in Utah. You can find the varieties for sale in local gardening outlets and through seed catalogs. Most grow well in Utah. Packman (50 days), Green Comet (55days) , and Premium Crop (65 days) have excellent production and eating quality.
Growing Broccoli In Utah
Broccoli prefers fertile, well-drained soils rich in organic matter for best growth. Most soils in Utah are suitable for broccoli production.
Before planting, incorporate 2-4 inches of well composted organic matter and apply all-purpose fertilizer (10-10-10).
Broccoli can be grown from seed or transplants. Seeds should be planted 1/44-1/3 inch deep and thinned too the final stand when plants have 3-4 true leaves. Plants removed at thinning can be transplanted to adjacent areas. Transplants are used to provide earlier harvest. Transplants should have 4-6 mature leaves and a well developed root system before planting out. Larger, more mature transplants are prone to form small, early heads (buttoning) which flower prematurely.
Planting and Spacing
Seeded or transplanted broccoli should be spaced 12-18 inches between plants in the row with rows 2-3 feet apart. Closer spacing (1 by 1 foot) can be used, but head size is reduced and side shoot development inhibited by these arrangements. Broccoli grows best and produces highest yields when temperatures do not exceed 75°F and is not seriously damaged by temperatures down to 28 °F. Broccoli grown for transplants should be sown 5-6 weeks before the expected planting date. Transplants may be planted 2-3 weeks before the last frost free date for the growing area. Seeded broccoli may be planted at the same time. For fall maturing broccoli, select early maturing cultivars and plant 50-75 days before the anticipated maturity date. The maturity date can be several weeks after the first fall frost. High summer temperatures reduce growth, decrease quality, and cause loose heads to form, which taste bitter.
Water broccoli deeply and infrequently while trying to maintain even soil moisture. About 1-2 inches of water are required per week. Use drip irrigation if possible to conserve water. Applying mulch around the plant also helps conserve soil moisture and reduce weed growth.
Growing Broccoli In Utah, or anywhere in the U.S. apply nitrogen based fertilizer (21-0-0) Four weeks after transplanting or thinning to encourage vigorous plant growth. Apply again when the broccoli head is the size of a quarter. After harvesting the main head, apply additional nitrogen fertilizer to encourage side shoot development. Place fertilizer 5 inches to the side of the plant and irrigate it into the soil.
Mulches and Row Covers
Plastic mulches help conserve water, reduce weed growth and allow earlier planting and maturity, especially with transplants. Hot caps and fabric covers are used to protect seedings and transplants form frosts. Fabric covers also protect young plants from insect pests. Apply organic mulches when temperature rise. These will cool the soil and reduce water stress. Organic mulches such as grass clippings, straw, and shredded newspaper also help control weeds.
Harvest and Storage
Broccoli heads should be harvested when the heads are compact but before the flower buds open. Mature heads are 6-12 inches in diameter and should be cut with stems 8-10 inches long. With additional water and fertilizer, broccoli will produce many 4-6 inch long side-shoots. Broccoli can be stored for 1-2 weeks at 32°F and 95% relative humidity.