Grow and Care for Cabbage

Grow brassicas in full sun and fertile, consistently moist ground timed for cool weather. Brassicas here means Brassica oleracea and B. rapa — cabbage, kale, broccoli, cauliflower, Brussels sprouts, and bok choy — not unrelated cool-season greens like spinach or Swiss chard.

Give it full sun, rich soil, and steady water — and time it for cool weather

Brassicas are cool-season crops. Temperatures between 60°F and 70°F produce the firmest, most flavorful heads. [1] Young transplants tolerate light frost once hardened, but seedlings exposed to 35–50°F for extended periods may bolt prematurely before a head forms. [2] Maintain even soil moisture throughout; a stretch of dry weather followed by heavy rain causes the inner leaves to expand faster than the outer ones, splitting the head.

Harvest when the head is firm, and cut at the base before it splits

Most heading types (cabbage, broccoli head, cauliflower curd) are ready 70 to 100 days from sowing, depending on variety. [3] Check by squeezing the head; it should feel dense, with no give. A head that stays on the plant after reaching full size will split if heavy rain follows dry weather.

1. Squeeze the head. If it feels firm and solid, it is ready. A soft or spongy center means it needs more time.
2. Cut cleanly at the base of the head with a sharp knife, leaving the outer leaves attached to protect it in storage.
3. For cabbage, leave the stump and a few outer leaves in the ground. The plant will often produce several smaller secondary heads over the next few weeks.
4. Store unwashed heads in a cool, humid space. A firm cabbage head keeps one to two months near freezing.

Kale and collards do not head. Harvest outer leaves from the bottom of the plant and work upward; the central growing point keeps producing until hard frost.

What causes head splitting, clubroot, and black rot

Head splitting is a watering problem, not a disease. Inner leaves expand rapidly after rain or heavy irrigation following a dry period. Harvest promptly once heads firm up; cutting the roots on two sides of the plant with a shovel also slows water uptake and buys a few extra days before splitting. [4]

Clubroot is a soil-borne pathogen that swells and distorts roots, causing wilting despite moist soil. Pull a suspect plant and check the roots; distorted, club-shaped roots confirm it. Once established, the organism persists as resting spores for 10 or more years. Raise soil pH to 7.0 by liming, improve drainage, and avoid replanting any brassica in that spot for at least four years. Do not move soil from an infected bed on tools or boots. [5]

Black rot shows as V-shaped yellow-to-brown lesions at the leaf edges, with veins turning black. It spreads through overhead watering and infected transplants. Use certified clean transplant stock, avoid working among wet plants, and rotate out of brassicas for three to four years. There is no chemical cure once the disease is established. [6]

Choose a type, see how to plant it, or try a container

Cabbage, kale, broccoli, cauliflower, Brussels sprouts, and bok choy all grow from the same cool-season playbook but differ in harvest stage, spacing, and season length. Browse all of them on Types of Brassicas. Spring and fall planting windows, transplant depth, and spacing are on Planting Cabbage. Compact and mini-head varieties that fit a 5-gallon pot are on Cabbage in Containers.

Time your planting for cool weather, keep soil moisture even, and harvest heading types before rain causes splitting. Rotate brassicas out of any bed that shows clubroot for at least four years.