Sow thinly 13mm (0.5in) deep in a seedbed in rows 15cm (6in) apart. Thin the seedlings to 7.5cm (3in) apart. However, best results come from sowing in cell trays using any good multi-purpose potting compost. As cauliflowers mature in a rush, avoid raising many plants at a time - five is usually suitable for small households.
The main sowing period is March to May, although early crops can be achieved by sowing under glass in January/February or sowing cultivars in the autumn in a glasshouse or coldframe.
Cauliflowers do best in very fertile soil, and digging in a bucketful of well-rotted manure or organic matter before planting, and raking in 150g per sq m of Growmore or other general purpose fertiliser, will help growth. Firm the soil by treading before planting.
If growth is checked, at any time during growth, they produce small, deformed heads. To avoid problems, plants well the day before transplanting and make a hole deep enough to hold the plant with the lowest leaves at ground level. Fill this hole repeatedly with water. This will fill the hole with soil and ensure the plant is sitting in a large area of moist soil. Firm the soil very well against the roots
Space summer and autumn cropping types 60cm (2ft) apart and winter cultivars 75cm (2.5ft) apart; spacing 30-45cm (12-18in) apart, provides mini, 'one person' curds.
Water well in dry weather, watering every 10 days, and applying sufficient water to thoroughly wet the root zone. Once the plants are growing well, add 30g per square metre of high nitrogen fertiliser such as sulphate of ammonia to boost growth and curd formation.
Start cutting when the heads are firm; once the florets start to separate, it is too late.
‘Cheddar’ AGM: Has orange-yellow flower-heads.
‘Graffiti’ AGM: Has deep purple heads.
‘Clapton’: With large white, heads, this is for summer to late autumn harvest. Club root resistant.
'Skywalker’ AGM: Autumn use with particularly large white curds.
Club root: Roots become swollen and distorted, leaves become pale and yellow and wilt easily. Plants may die.
Remedy: Improve drainage, lime to make it more alkaline, remove and burn all infected plants immediately, avoid moving soil around on your boots and tools. Grow your own plants or buy from a reputable source. Grow resistant varieties. Do not grow cabbages in affected soil.
Read more information about club root
Birds: Birds, especially pigeons, can strip the leaves of cauliflowers, preventing the plants from growing and the curds forming.
Remedy: Protect the plants from birds by covering them with netting or fleece.
Read more information on damage caused by pigeons
Caterpillars: The larvae of several butterflies and moths feed on the leaves of brassicas, including cauliflowers, making holes in them.
Remedy: Treat cabbage white and other caterpillars with synthetic pyrethroid insecticides or grow beneath insect-proof mesh. Protect the curds of summer varieties from the sun by bending a few leaves over them; do the same with winter varieties, to protect against frost - particularly important with the less hardy romanesco types.
Read more information on cabbage caterpillars