Gardener's HQ Guide to Growing Cauliflower

How to Grow Cauliflower in Your Garden

Cauliflower, scientific name Brassica oleracea var. botrytis, is an annual or biennial cool season green plant from the cabbage family.

The plant derives from Kale and is grown for its central floral head and can be grown all year round. It is rich in vitamins and iron, making it a great vegetable to grow for health purposes.

There are two main classifications of Cauliflower: the summer which is the true cauliflower and the winter, which is a type of broccoli. The names winter and summer are a little misleading as summer cauliflowers are often grown in winter under glass.

They reach an height of one to two feet (30–60 cm) and a spread of about 18 inches to 3 feet (45–90 cm). They therefore require a large planting area.

Cauliflower requires more care and attention than cabbage for successful growth, and has a reputation for being a finicky plant to grow.

Growing Cauliflower
Cauliflowers by Nick Saltmarsh.

Soil Preparation for Growing Cauliflower

A sunny spot is the best location for growing cauliflower; they can tolerate light shade, but this will greatly lengthen the time to maturity. A well-drained soil is essential.

Dig the soil thoroughly a few months before planting, as plants perform best in well consolidated soil. Work in some organic compost or manure when digging the soil.

It is important that the soil is fertile and firm, as infertile and loose soils are the main causes of cauliflower crop failure. They will perform best in a bed located in a sunny spot and with a fairly heavy soil.

In locations that have poor soil it is especially important to dig in a lot of well-rotted organic compost, or manure as early as autumn to give the soil ample time to settle and become firm. Bear in mind that it is vital to feed to soil well , so that you need to use additional feeds of the plant as little as possible, this is generally a good tip whatever plants are growing in your garden.

Adding lime to the soil is essential because overly acidic soil encourages club root, a disease of the brassica family (and one of the biggest fears of gardeners). Lime should be added to the soil so that its pH is in the range of 6.5 to 7.0. Applying a dressing of fertilizer is also important. However, avoid digging in, but rake gently over the surface of the soil so that the bed to remain firm.

Planting Cauliflowers

As cauliflowers tend to mature at the same time it is not recommended to grow more than five or six for an average family garden.

Sow cauliflower seeds around half an inch deep (1.25 cm) into individual seedling trays or pots; or into rows 6 inches (15 cm) apart, and then thin within the row. Seeds are expected to germinate in one or two weeks. Following germination, place the seedlings in a well-lit area that is approximately 60°F (15°C).

The seedlings are ready to harden off about six weeks before planting out.

Plant the seedlings about 18–24in (45–60 cm) apart, in rows spaced 30–40 inches (75–100 cm) apart.
The plant will grow best in full sun and should be watered daily.

Cauliflowers should be transplanted in the evening in order to minimize distress, and to promote quicker recovery place as much soil around the roots. Plant as firmly as possible as this will lead to tighter cauliflower heads. The seedlings should be watered right after transplanting, but be sure to avoid any form of wilting as this could result in permanent damage to the damage the plant.

Cauliflower varieties
Differently colored cauliflower varieties by Market Manager.

Cauliflower Care

Although cauliflower prefers to be grown under full sun they can tolerate partial shade (delays maturity). Since the plant is a heavy feeder, it will benefit from applications of calcium, magnesium, and boron-rich fertilizers during the early stages of growth.

Tie heads to blanch white flower-headed varieties.

The plant needs to be watered on a daily basis to prevent drought, but do not over-water. Remove weeds only when absolutely necessary and cultivate lightly to avoid damaging roots.

Troubleshooting Cauliflower Problems

Minimizing pest problems is essential to successfully grow cauliflower. Cabbage root fly and caterpillars are some of the most common pests.

Prevent club root by adding lime and improving drainage; remove and destroy any infected plants immediately.

Covering the plants with gardening fleece while the plants are young is recommended to prevent butterflies laying eggs, alternatively grow beneath an insect resistant mesh or treat with pyrethroid insecticides. Since caterpillars feed on the underside of the leaves it is easy to simply pick or squish them off. A nematode spray can also prevent pests from destroying the plant.

Cover with netting to prevent birds from stripping away the leaves.

Harvesting Cauliflowers

It is advisable to begin cutting back some cauliflower heads while they are still fairly small, as this can prevent a mass of crops within a few days of each other.

The size of the head depends on the kind of variety planted. Cut the stalk with a sharp knife but make leave some surround the head for protection.

It is best to harvest cauliflowers early in the morning when they are at their most succulent.

Although growing Cauliflowers are frost tolerant, do not subject mature heads to frost as it will ruin them.

I hope that you enjoyed this guide on growing cauliflower plants. You may also enjoy the following Gardener's HQ Brassicaceae growing guides: How to grow Wallflowers and Ionopsidium plants, or maybe this one on the companion plant Hyssop (use to distract cabbage moths).