Cabbage

Cabbage is a highly nutritious, hardy, easy-to-grow, cool weather vegetable with a long storage life. Growth is best where the cool season is long with mild temperatures between 45 and 75 degrees. The Brassicaceae family—familiarly called the cabbage family, cruciferous, and cole crops—also includes broccoli, cauliflower, Brussels sprouts, collard greens, kohlrabi, and kale.

Planting

Select disease-resistant, early- or late-maturing varieties for a long, staggered harvest.
Sow seeds in pots or flats March-April; set out transplants after 6-8 weeks in April-May.
Sow seeds for fall and over-wintered crops in July-mid-August or September; set out August-September. Long-season types overwinter for December-March harvest.
Follow label directions on seed packs for spacing transplants and watering. Overcrowding and dry soil result in poorly formed heads.
Grow cabbages year-round in moderate coastal areas; monitor weather to avoid having young plants exposed to high summer temperatures or frigid winter lows which cause them to bolt.
Plan to rotate cabbages and other cole crops regularly to avoid insect and disease pests.

Culture

Amend beds with compost prior to planting to improve drainage. Add compost or other organic mulch to soil surface when cabbages are 4 in. tall.
Irrigate in the absence of fall, winter, or spring rains. Keep soil moist but avoid overwatering and underwatering—both may cause heads to split open.
Allow cabbages to overwinter when frosts are infrequent and light.

Harvesting

Plan on 70-100 days to harvest; shorter or longer times depend on variety.
Harvest as soon as heads are mature: firm with rounded, filled—not loose—heads.
Leaving heads in the garden beyond maturity results in bolting or split heads.
Protect plants from a hard freeze or harvest beforehand.
Store varieties that mature early for 3-6 weeks; late-maturing cabbages store longer.

Problems

Include Savoy types for pest and disease resistance and successful storage after harvest.
Stay alert for chewing and sucking insects. Caterpillars and worms can be treated with organic treatments such as Bacillus thuringiensis (Bt). To avoid applying insecticides, handpick these and chewing insects such as harlequin bugs.
Apply a collar around seedlings to prevent cutworm damage.
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 as well as low or high temperatures.

Additional Information

Sonoma County Master Gardener Vegetable Planting Summary.
https://sonomamg.ucanr.edu/Food_Gardening_with_Less_Water/
http://ipm.ucanr.edu/home-and-landscape/cabbage/index.html
http://ipm.ucanr.edu/home-and-landscape/cabbage/cultural-tips/

February 2022