Fothergill's Growing Guide: Cauliflower

Average time to harvest

16-20 weeks

Sowing depth

2cm

Soil type

Well cultivated, fertile soil

Cauliflower is one of the most rewarding vegetables you can grow. While they are a little fussier than other brassicas, we think the reward of cutting your first heads is well worth the effort. Plus, the freshness and flavour of homegrown vegetables is better than anything you might pick up in a supermarket.

Fothergill’s is here to guide you through all you need to know about how to grow your own cauliflower with confidence.

Did you know?

Its botanical name is Brassica oleracea Botrytis. A descendant of wild cabbage, 'cauliflower' means ‘stem flower’ in Latin.

The cauliflower can be an annual, biennial or even a perennial plant, but most often completes its life cycle within one year.

Like all brassica plants, cauliflowers don’t like to grow in acid soil, and they prefer cooler conditions.

There are many different coloured varieties including white, yellow, orange, purple and green. The green Romanesco variety is particularly attractive with its unique spiral florets, and has a distinct, nutty flavour. Coloured cauliflowers often taste milder and sweeter compared with the standard white variety.

Growing at a glance

Cauliflowers should be grown in a deep, rich soil. Although frost tolerant, they prefer a sunny, sheltered area.

Usually sown in to late spring, they require plenty of space when planted out into their final growing position.

Keep the soil moist, especially during dry spells, and give them a high nitrogen feed as the heads begin to mature. Ensure the area remains weed free.

Sowing seed

Cauliflower can be sown indoors using a standard or a modular seed tray, filled with a seed compost mix. Tamp the compost down to create a firm surface, then sow thinly. For modular trays create a 2cm hole in the centre. Place two seeds in the hole and cover over with compost. Water gently and place tray in a greenhouse, cold frame or windowsill to germinate.

Germination should occur within 14-28 days, or slightly faster if you’re using a heat mat, heated greenhouse or heated propagator. Once they’ve germinated, give them plenty of light so they don’t become leggy.

Direct sowing into the final growing area, or into a separate seed bed, can be done from late March to April, when the soil is warmer and more workable. Prepare the open growing area by adding plenty of organic matter and working it into the soil. Firm the soil down with the back of a rake, or use your heels to walk over the growing area, and then create a fine, level tilth. Water the area before sowing to avoid dispersing the seed.

For seed beds, create drills 1cm deep and 15cm apart. Rows should be 60cm apart, if you’re sowing directly. Sow seed thinly, then cover over with fine soil. Germination should take between 14-28 days. If sowing early in the growing season, a cloche or horticultural fleece maybe needed to protect the sown area.

Pricking out

Once two seedlings are firmly established in each seed module, remove the weaker seedling allowing the other one to grow on. To avoid disturbing the
roots, either pinch-out the weaker seedling or cut it away. Keep soil moist.

For plants directly sown into the final growing area, thin seedlings to 60cm apart.

Hints and tips

To protect the maturing curds from frost and rain damage, cover over with the long leaves and gently tie them together.
To help retain moisture around the growing plant, mulch the area.
Cauliflower leaves are edible. They have a strong flavour and are ideal for a stock.

Growing on

When indoor seedlings are 10-15cm high, they are ready to be planted out into their final growing positions. Prior to planting out, let them harden off outside for a week beforehand by bringing your plants outside for a few hours every day so they can acclimatise to outside conditions.

The growing area should be prepared with plenty of organic matter worked into the soil, adding a general-purpose fertiliser, if necessary. Firm the growing area down with the back of a rake, or use your heels to walk over the growing area, and then create a fine, level tilth. Plant deeply, up to its first set of
leaves, and firm around the roots. This will help them establish a good root system and prevent wind rock. Plants should be spaced 60cm apart in rows 60cm apart. Water in well. This also applies to plants that were grown and transplanted from a seed bed.

Plant maintenance

As plants mature, mound up around the base of the plants to help support them.

Water regularly, keeping the soil moist, and keep the area weed free. Provide a high nitrogen feed as plants begin to mature.

Harvest when the plant curds have fully formed and are firm. Cut away from the plant just below the head. Remove the rest of the plant from the growing space sooner rather than later, to prevent possible pests and diseases affecting the area.

Jargon busting

Brassica

Family of vegetables which include: broccoli, brussels sprouts, cabbage, cauliflower, kale and swede.

Propagator

A covered, typically heated container filled with compost, used for raising seeds.

Tilth

Surface soil which is fine and crumbly.

Drill

A trough made for seeds to be sown in.

Germination

When a seed begins to grow and its first shoot appears.

Pricking Out

Removing seedlings from growing trays and planting them into individual pots to grow on.

Curds

The edible florets of a cauliflower.

Mulch

Either well-rotted manure, leaf mould or compost which is placed on the surface of the soil. This not only acts as a plant feed, but it supresses weeds and helps to retain moisture.

Pinching Out

A form of pruning, using forefinger and thumb, to remove a soft stem, encouraging plants to become bushier.

Common problems

Birds (especially pigeons) and caterpillars will happily eat the leaves of the plants, so place fine netting over the crop at the time of planting. This will also deter the white cabbage butterfly from landing on the plants to lay its eggs during the summer months; an infestation of caterpillars can quickly devastate a crop.

Cabbage root fly larvae feed on brassica roots. When planting into its final growing position, place a brassica collar around its stem, just above the soil. This will help prevent cabbage root fly from laying eggs at the base of the plant, and its hatched larvae from eating and destroying the roots.

Club root is a fungal infection that damages the roots, leaving them swollen, distorted and stunted. The foliage can also discolour. If plants are infected, remove from site and destroy. Wash hands, tools and boots to help prevent the spread of infection. Avoid planting brassicas in areas where club root has occurred. Buy seed varieties that have some degree of club root resistance.

Ready to get planting?

Now that you’re ready to grow your own, it’s time to take a look at our range of cauliflower seeds. Get ready to start one of the most rewarding growing journeys any budding gardener can experience!