By Josie Borlongan, Garden Guides Contributor
About CauliflowerCauliflowers are grown as annuals or biennials, forming an average head (or curd) of about 8 inches (20 cm) in diameter; the plants are 18 to 24 inches (45 to 60 cm) tall, with a spread of three feet (90 cm).
Cauliflowers are a cool-season crop and do not usually grow well in areas with high summer temperatures. Only the head (the white curd) is eaten while the stalk and green leaves are discarded. They can be eaten either cooked or raw as in salads.
Site PreparationSeveral cultivars are frost hardy. An open situation with fertile, well-drained, moisture-retentive soil is required for cauliflowers. Overwintering cauliflowers need to be sheltered outside and are not grown under cover through maturity. Cauliflowers require a pH of 6.5 to 7.5 and medium nitrogen levels using fertilizer with 21 percent N content 1 1/2 to 2oz. per square yard (45 to 55g per square meter).
Special FeaturesMost types of cauliflowers have cream or white colored curds but they also come in green and purple curds. Cauliflowers are classified by the main season of use with winter distinction for frost-free or frost-prone areas, early summer and summer and fall varieties.
Choosing a VarietyThe recommended varieties are:
Early Summer; Early Dawn, Early Snow Ball, Milkyway, Minuteman, Pathfinder, Quasar and Snow Crown.
Summer and Fall; Amazing, Cumberland, Fremont, Serrano, White Rock and White Sails.
Green Cultivars; Chartreuse.
Purple Cultivars; Burgundy Queen, Graffiti and Violet Queen.
PlantingCauliflowers are sown based on the correct cultivar chosen and the appropriate sowing time.
Winter (frost-free areas): Sow in late spring; plant in summer; spacing 28 inches (70 cm).
Winter (frost-prone areas): Sow in late spring, plant in summer; spacing 25 inches (63 cm).
Early summer: Sow in fall or early spring (sow under glass); plant in spring; spacing 21 inches (52 cm).
Summer and Fall: Sow mid- to late spring; plant in early summer; spacing 22 to 25 inches (55 to 63 cm).
Sow in seed trays, cell packs or a seedbed for transplanting. Cauliflowers may be sown in their natural environment and thinned to the correct spacing. Seed germinates best at a temperature of 70 degrees F (21 degrees C). Cauliflowers can grow under cover or cloches. Apply mulch to retain as much moisture in the soil as possible.
CareCauliflowers need to be watered regularly during the growing season. Watering at a rate of 5 gallons per square yard (23 liters per square meter) is necessary every two weeks during dry season. Apply either a nitrogenous fertilizer or organic liquid fertilizer during spring.
In winter and early spring, mature curds or overwintering types may need protection from severe cold and hard frost. Use the leaves to wrap around the central curd, securing them with soft spring to prevent damage caused by the cold.
Flea beetles, slugs and snails, damping off, cabbage root maggots, whiptail and cutworms all affect young plants. Caterpillars, whiteflies, mealy aphids and clubroot attack plants at all stages of growth. Cauliflowers can be attacked by pollen beetles so precautions should be used to prevent them from happening.
Harvesting and StorageCauliflowers may be harvested based on their type. The time of sowing to maturity varies from approximately 16 weeks for summer/fall cauliflowers to about 40 weeks for winter ones.
Winter (frost-free areas): Harvest during winter or early spring.
Winter (frost-prone areas): Harvest in early spring.
Early summer: Harvest in early to midsummer.
Summer and Fall: Harvest in late summer to late fall.
Cut the curds while they are still firm and tight. After 15 weeks of sowing, the mini-cauliflowers can be ready for picking. Do this immediately to avoid deterioration. All types of cauliflowers freeze well.