Cauliflower is a cole crop in the Brassicaceae (cabbage) family along with broccoli, Brussels sprouts, kale, kohlrabi, and cabbage. Of these, cauliflower is the most sensitive to low and high temperatures and does best when there is moisture in the air. Careful attention must be given to soil preparation, watering, and protecting developing heads.
Cool Season Growth
- Amend heavy soil with compost to improve drainage and encourage good root development.
- Grow cauliflower in both the spring and fall-winter cool seasons.
- Plan on 80-110 days to harvest from seeding, depending on weather and variety planted.
- Sow seeds in pots or flats March-April; transplant April-May into July. Sow seed July-mid-August; transplant August-September for harvest in fall-winter.
- Wait to transplant until seedlings have 4-6 leaves; bury stems up to the first leaf.
- Do not allow seedlings to become rootbound before transplanting or heads will be stunted.
- Set plants 18 in. apart in rows 2 ft. apart. Overcrowding results in poor heading.
- Keep soil evenly moist in the absence of rains.
- Water deeply by drip or in furrows, being careful to avoid wetting foliage.
- Cover soil with at least 2 in. of compost or other organic mulch to provide continued nutrient release and control weeds.
Strive for success
- Select hardy and disease resistant varieties such as ‘Snow King’, ‘Snow Crown’, ‘or ‘Snowball Y’.
- Avoid diseases by rotating all garden crops and not planting cole crops in the same spot year after year to prevent pest build-up in the soil.
- Prevent interference with rapid growth by keeping soil moisture even and covering crops when temperatures fluctuate or pests appear. Very cold air in spring may result in smaller heads.
- Stay alert for chewing and sucking insects. Caterpillars and worms can be treated with organic treatments such as Bacillus thuringiensis (Bt), or handpicked.
- Use insecticidal soap or a strong jet of a garden hose to displace aphids or cover transplants with row covers to shield plants from insect damage.
- Fold or tie upper leaves over 3-in. heads to protect yellowing from sun exposure.
- Harvest good sized heads at about 5-6 in. to prevent curds from separating.
- Sonoma County Master Gardener Vegetable Planting Summary.