There are several cauliflower kinds available, grouped according to the season of harvest. There are slower-growing kinds for harvesting in late winter and spring and faster-growing varieties for crops in the summer and autumn. You can nearly always have cauliflower if you purchase a range of varieties.
To fit the space you have available, different types grow to a variety of sizes, from enormous heads (curds) up to 30 cm (1 ft) to tiny cauliflowers that grow to just 10 cm (4 in) broad. Choose smaller, quicker-growing summer or mini types if you're short on space since winter varieties tend to be larger and slow-growing, taking up a lot of area for six months or more.
Sowing indoors
Cauliflowers perform better when they are started indoors, on a windowsill, or in a greenhouse where the temperature can be controlled and the seedlings are shielded from the elements and most pests. Consider sowing your cauliflower seeds individually in modular trays to help reduce root disruption when you move them outside. Seeds should be sown about 1 cm deep. In around two weeks, cauliflower seeds should start to germinate. Be sure to water frequently and keep the seedlings warm and well-lit. As the roots of young cauliflowers fill the module, which takes about six weeks, the plants are prepared to be transplanted outdoors.
Sowing outdoors
Around the middle to end of the spring, cauliflower can be planted outside. Choose a spot that is sunny, and has rich, deep soil that is moist but free-draining. Digging in a few buckets of well-rotted manure or garden compost in the autumn prior is great to get the soil ready for the growing season. Remove any weeds immediately before seeding or transplanting, then firm the soil by thoroughly treading it. Cauliflowers require firm ground, much like the majority of brassicas do.
Thinly plant the seeds along a shallow drill that is only 2 cm (34 in) deep. If using a temporary seedbed, space rows 30 cm (1 foot) apart. Rows should be spaced 40-75cm (18-28in) apart if being sown in their final location (see seed packets for details). Brassica pests can be avoided by shielding seedlings from slugs and snails and covering plants with insect-proof mesh. Start removing some seedlings, typically in a row, to increase the distance between the remaining seedlings. This helps with overcrowding, which can impede their ability to grow.
As they reach a height of 10-15cm (4-6in), or around six weeks old, they are moved to their final growing site. Avoid delaying too long because doing so later risks causing plants to bolt (flower early), destroying the harvest. Before being transplanted, indoor-raised plants need to be acclimatised to outdoor conditions, so they can survive and grow.
To transplant cauliflowers, follow these steps:
Dig a hole with a trowel that is deep enough for the plant's lowest leaves to be at ground level.
Try not to disturb the roots as you carefully set the plant in the hole, then repeatedly fill it with water. Often known as "puddling it," this procedure ensures the plant is positioned in a sizable area of moist soil.
Around the plant, firmly press the soil.
Avoid growing too many cauliflowers at once because they don't keep well and have a tendency to mature quickly. You can spread out your harvests by sowing a number of small batches around three weeks apart.
Watering
Cauliflowers prefer a lot of moisture that drains freely without becoming waterlogged. Attempt to maintain constant moisture in the ground at all times; otherwise, plants may stop growing and the head may fail to form correctly. Then, during periods of dry weather, water plants at least once a week in order to maintain robust, continuous growth free from interruptions. Whenever the curds begin to form, make careful to water frequently as well.
In summer, the hot sun can cause white cauliflower heads to turn yellow – fold the leaves over the curd to protect them. In winter, protect the developing head from hard frosts in a similar way.
Mulching
Add a thick layer of mulch, such as garden compost or well-rotted manure, to the soil to help retain moisture and keep weeds at bay. Just make sure to leave a tiny space around the stem's base.
Feeding
Use a heavy nitrogen fertiliser once new cauliflower plants are growing but before they begin to create curds. This will promote growth and facilitate the development of curds.
Our 'Grow Your Own' Soluble Feed with Micro-Nutrients & Seaweed contains nitrogen, so make sure to buy some before growing your cauliflower