Temperature and timing key
One of the trickier members of the brassica family, temperature and timing are important factors in mastering the art of growing a cauliflower.
Pull off one of the striking lime, violet or orange caulis generally seen only at fancy greengrocers, then you can officially call yourself a vegetable-growing pro.
SOW AND GROW
■ When to sow: December to March in warmer areas and November to January in cooler areas.
■ When to transplant: March to May and August to October in warmer areas; February to April and August to October in cooler areas.
■ Position: Full sun.
■ Harvest: 14-26 weeks.
GET STARTED
Caulis can be started from seed from early summer through to mid autumn in warmer climates; and late spring to mid summer in cooler parts of the country.
Seedlings can be planted in autumn and from late winter to mid spring in warmer regions; and from late winter to mid spring in cooler regions.
STEP BY STEP
■ Sow cauliflower seed direct at a depth of 5-10mm in well-cultivated soil, or start them off in trays of seed-raising mix inside a sunny spot or a glasshouse.
■ Keep newly planted seed moist and warm.
■ Expect signs of sprouting in 7-14 days.
■ Thin the seedlings and. If growing in trays, pot them on into larger pots if necessary. Transplant into the garden when the plants are about 10cm high.
■ Cauliflowers are large plants and in the garden most cultivars need to be spaced about 40-50cm apart.
GROWING TIPS
Cauliflowers can be grown throughout Aotearoa but plants only form good-sized curds in low temperatures. Prepare the bed with compost, aged manure and a bit of lime before planting. Keep well watered during the growing season; but direct water toward the rootzone of the plant rather than overhead where the curds are developing.
Don’t overdo it with high-nitrogen fertilisers as these can lead to leafy plants with small heads. Side dress with a liquid fertiliser every two to three weeks.
Harvest when heads are firm to touch. Don’t wait too long or curds separate and start flowering. If you harvest the main head but leave the stem and roots intact, a few smaller caulis will grow.
STANDOUT VARIETIES
‘‘Snowball’’ is a fast grower, maturing around 12 weeks from transplanting. Grow it as a mini cauliflower by planting it 30cm apart and harvesting when its heads are 10cm across. It’s also a great variety for a pot, as is ‘‘Mini White F1’’, which has heads measuring 10-15cm. Just remember to water pots daily during hot weather. ‘‘Clapton F1’’ has good resistance to club root. ‘‘All Seasons’’ and ‘‘All Year Round’’ can be grown throughout the year in cooler regions, but will need to be protected from butterflies.
For coloured caulis serve raw if you don’t want to lose the colour. Otherwise cook as per usual or as recipe requires.
‘‘Romanesco’’ is the most beautiful of them all, its architectural-looking spikes resembling chartreuse coral.
TROUBLESHOOTING
Protect cauliflowers, particularly seedlings, from slugs and snails with cloches or go on a slug hunt at night and carefully fossick through the leaves, remove them by hand and squash.
In warm weather, caulis are plagued by whitefly and white cabbage butterfly caterpillars. Protect plants, including trays of seedlings, with a physical barrier such as an old net curtain or horticultural mesh. You can also inspect daily and pick off cabbage butterfly caterpillars by hand.
Remove whitefly by spraying plants with soapy water or blasting the undersides of the leaves with your hose regularly. This will discourage aphids too.
Avoid club root, the brassica fungal disease, by adding lime to your soil before planting and by rotating your crops every year.