With good preparation and ample moisture, cauliflower are easy to grow in the home garden and the effort in growing will be rewarded by tender, mild flavoured flower heads that are so healthy.

Cauliflower is rich in vitamin C anda good source of vitamin K, protein, thiamin, riboflavin, niacin, magnesium, phosphorus, fiber, vitamin B6, folate, pantothenic acid, potassium, and manganese. As a member of the cruciferous family, it contains sulforaphane that is thought to be protective against cancer.

Growth habits and planting needs

Cauliflower need at least 6 hours of full sun to grow properly so ensure that the site chosen is open and sunny. They are best planted out when the hotter months have passed because the plants do not do well in heat.

It is best to start cauliflower in paper pots to avoid disturbing roots and then plant out in the garden in 4-6 weeks. Sow the seeds 6-12 mm deep in the paper pots and keep moist throughout but not allow to get waterlogged.

Whilst the seedlings are growing the garden bed should be prepared ahead.

Preparation of the garden bed is very important to the successful growing of cauliflower. Ideally they should follow a legume crop in the crop rotation cycle to ensure that there is enough nitrogen naturally available in the soil.

Cauliflower are heavy feeders and prefer a fertile, well drained soil that is high in organic matter. Dig over the soil well and add some well rotted compost and some aged manure. Cauliflower like the soil to be slightly acidic with a pH of 6.0-7.5 so test the soil and correct if needed.

After hardening of the seedlings plant 40 – 60 cm apart. The extensive root system occupies up to 75 cm on all sides of the plant so keeping the area weed free is important to prevent competition.  The root system below the soil is dense and compact and adequate space is needed around each plant to ensure good size flower heads to develop to maturity.

The flower heads need constant moisture to develop well and watering should reach a depth of 15 cm. A thick layer of mulch around the plants will conserve moisture and stop evaporation while keeping the roots below cool.

This diagram from Root Development of Vegetable Crops by John E. Weaver and William E. Bruner shows the root development (grid in ft) under optimal conditions. It also shows the importance of keeping weeds away to prevent competition with surface roots.

When the flower heads begin to develop tie leaves loosely around the head so that it is protected from the sun and will be white.  Leave enough room for air to circulate while still protecting the head from browning. Check regularly and always water from below.

Feed regularly with fish emulsion or weak compost tea.

Companion Plants

Bush beans, beetroot, celery, cucumber, onions, marigold, nasturtium, rhubarb, parsley, sage, dill, chamomile

Not compatible with climbing beans, tomato, chili, capsicum, eggplant, strawberry, mustard

Harvesting

The mature cauliflower will be about 15 – 30 cm in 15 to 22 weeks. Harvest the heads

whilst the buds are still tight cutting the heads with a few leaves around them using a sharp knife.

Store the cauliflower in the crisper cut side down in breathable plastic bags for up to a week. Florets that are prepared last less and should be use in 3-4 days.

Cauliflower can also be successfully blanched and frozen and can also be pickled.

For the best taste use the cauliflower close to harvest and also cook the tender leaves.