Cauliflowers are a cool weather crop. Hot temperatures can reduce head development. In summer you can cover the head with the plants leaves.
When growing Cauliflower, the soil should be prepared well in advance, especially if you are enriching the soil with organic matter. If you are sowing the cabbage seeds in spring, prepare the soil in autumn by digging in plenty of well-rotted compost or manure. The soil should have been dug deep. Cauliflower grows well in loamy, well drained soils.
Sow the seeds at ½ inch deep. About 6 weeks after sowing the seedlings they should be ready to harden off before planting out. Harden the seedlings off a week before planting out by gradually increasing the amount of time the plants are left outside and the amount of sun the plants receive.