Cauliflower – Growing Guide

Overview

• Name: Cauliflower
• Botanical Name: Brassica oleracea var. botrytis
• Plant Family: Brassicaceae (Mustard Family)
• Native to: Mediterranean region

Description

Cauliflower is an annual cool-season vegetable with a rosette of large, coarse, bluish-green leaves growing from a thick central stem. The edible part of the plant is a dense cluster of undeveloped flower buds known as the “curd.” The curd is usually white but can also be purple, orange, or green (Romanesco), depending on the variety. The plant can reach a height of about 45-60 cm (18-24 in) and a spread of 60-75 cm (24-30 in).

Interesting Facts

• Cauliflower was first documented in the 6th century B.C. by Greek philosophers.
• The name “cauliflower” derives from the Latin words ‘caulis‘ (cabbage) and ‘floris‘ (flower).
• Cauliflower is a close relative of broccoli, kale, cabbage, and Brussels sprouts.
• This vegetable is an edible flower, as the part of the cauliflower that we eat, known as the head or curd, is the plant’s undeveloped flower buds that are tightly clustered together.
• The curd can sometimes have a purple hue due to exposure to sunlight, but this doesn’t affect flavor.
• Plants from the Brassica family, such as cauliflowers, are rich in sulfur-containing compounds called glucosinolates, which may help lower the risk of various diseases, including cancer.
• Cauliflower rice, a low-carb substitute for rice, has gained popularity in recent years.
• The vegetable can also be used to make a gluten-free pizza crust or mashed like potatoes.

Basic Growing Information

• Sun Requirements: Full sun
• Water Requirements: Medium to high
• Soil Types and Properties: Fertile, well-draining loamy soil rich in organic matter
• Soil pH: 6.0 to 7.0
• Pot Size for Container Growing: Minimum of 30 cm (12 inches) deep and wide

Planting

Cauliflower is a cool-season crop, best grown at temperatures between 10-24°C (50-75°F). It requires consistent cool temperatures to prevent ‘buttoning’, which is the formation of several small heads instead of one large one.

It’s less tolerant of cold than its relatives, so it’s advisable to plant cauliflower after the last frost has passed to prevent damage from sub-freezing temperatures. In cooler regions, it’s optimal to grow cauliflower as a autumn crop (one that is harvested in autumn), as mature plants are the only ones that can withstand frost in autumn (fall).

• Best Time to Plant:
  • Climates with freezing winters: Start seeds indoors 4-6 weeks before the last frost date; transplant outdoors in early spring.
  • Climates with milder winters: Plant in late summer or early autumn for a winter harvest.

Note: Check gardening calendars for the best planting times in your location.

• Spacing: 45-60 cm (18-24 inches) between plants, and 60-75 cm (24-30 inches) between rows. Plant spacing will greatly affect the final size of the cauliflower head.
• Seed Sowing Method: Sow seeds directly into ground, or sow seeds into seed tray and then transplant seedlings
• Seed Sowing Depth: 0.5 cm (¼ in) deep
• Time to Harvest: 15-22 weeks from seed planting
• Mature Height/Spread: Approximately 45-60 cm (18-24 in) tall and 60-75 cm (24-30 in) wide
• Grown From: Seeds

Seedlings are ready for transplanting around 6 weeks of age, following a period of hardening off where they are gradually acclimatised to outdoor conditions.

Care and Maintenance

• Watering Tips: Water deeply once a week, ensuring consistent moisture throughout the growing season. Keep soil consistently moist but not waterlogged, and do not let the soil dry out, as cauliflower requires consistent moisture levels throughout the growing season to produce large, tender heads.
• Fertilisation: Cauliflowers are heavy feeders and benefit from the application of balanced fertiliser every four weeks during the growing season, or from an additional side-dressing of fertiliser about halfway through the growing period.
• Pruning: Remove yellow leaves to conserve plant energy
• Support: Generally not needed unless grown in windy areas

What is Blanching of Cauliflower Heads?

Cauliflower heads may become discolored due to exposure to sunlight. To prevent this, a technique known as ‘blanching’ is used when the head is between 2.5–5.0 cm (1–2 in) in size, to keep the head white.

• The process of blanching of cauliflowers involves tying the longest outer leaves over the head with twine.
• Remove the twine occasionally to monitor the head’s growth, inspect for pests, and let the head dry after rainfall.

There are also self-blanching varieties that produce leaves which naturally cover the head, eliminating the need to use this method.

Growing Difficulty

• Moderate Difficulty

Growing Tips

• Protect cauliflower seedlings from frost with cloches or fleece, or by breaking a few leaves over the curd.
• Cauliflowers should always be adequately watered, particularly during their initial growth phase, to prevent the formation of undersized heads.
• In varieties that need this, blanch the heads by covering them with leaves to maintain whiteness and tenderness.

Companion Plants

• Good companion plants include: Celery, spinach, and beans
• Avoid planting near: Strawberries and tomatoes

Common Pests and Diseases

• Pests: Aphids, flea beetles, cabbage worms, slugs
  • Prevention: Use floating row covers, apply neem oil.
• Diseases: Clubroot, black rot
  • Prevention: Rotate crops, ensure good drainage.

Harvesting

• Harvest Time: Cauliflower heads are ready for harvest when the heads are firm and compact, and reach 15-20 cm (6-8 in) in diameter, usually about 7 to 12 days after blanching begins. Cauliflower heads can rapidly become overmature, which diminishes their quality, so it’s crucial to harvest the heads while they remain firm and the individual florets are not yet distinguishable.
• Harvesting Tips: Cut the head from the base with a sharp knife, leaving some of the central leaves attached which will protect the head.

Propagation

• Produce New Plants From: Seeds

Culinary Uses

• Cauliflower can be steamed, roasted, stir-fried, mashed, or used as a low-carb substitute for pizza crust, or in the place of rice or mashed potatoes.

In conclusion, cauliflower is a versatile and rewarding vegetable to grow. With proper care, it will reward you with a delicious and nutritious harvest that can be enjoyed in various culinary creations throughout the year.

Feel free to share your carrot growing tips in the comments below, and include your climate/hardiness zone if it’s helpful.