Cabbage: Indoor or Direct Sow or Potted Vegetable
How to Sow and Plant
Cabbage may be direct sown or started indoors early for fall and spring crops, or purchased as transplants for a fall crop.
Sowing Seed Indoors:
- Sow seeds from spring to early summer in the north; in the south and other frost-free areas, sow from fall to spring.
- Start seeds indoors about 8 weeks before outdoor planting.
- Sow seeds ¼ inches deep in seed-starting formula
- Keep the soil moist at 70 degrees F
- Seedlings emerge in 10-21 days
- As soon as seedlings emerge, provide plenty of light on a sunny windowsill or grow seedlings 3-4 inches beneath fluorescent plant lights turned on 16 hours per day, off for 8 hours at night. Raise the lights as the plants grow taller. Incandescent bulbs will not work for this process because they will get too hot. Most plants require a dark period to grow, do not leave lights on for 24 hours.
- Seedlings do not need much fertilizer, feed when they are 3-4 weeks old using a starter solution (half strength of a complete indoor houseplant food) according to manufacturer’s directions.
- If you are growing in small cells, you may need to transplant the seedlings to 3 or 4 inch pots when seedlings have at least 3 pairs of leaves before transplanting to the garden so they have enough room to develop strong roots.
- Before planting in the garden, seedling plants need to be “hardened off”. Accustom young plants to outdoor conditions by moving them to a sheltered place outside for a week. Be sure to protect them from wind and hot sun at first. If frost threatens at night, cover or bring containers indoors, then take them out again in the morning. This hardening off process toughens the plant’s cell structure and reduces transplant shock and scalding.
Sowing Directly in the Garden:
- Sow seeds from spring to early summer in the north; in the south and other frost-free areas, sow from fall to spring.
- Sow in average soil in a sunny location in early spring or in midsummer for a fall crop.
- In rows 2 feet apart, sow seeds thinly and cover with ¼ inch of fine soil.
- Keep evenly moist. Water gently.
- Seedlings emerge in 10-21 days.
- Thin to stand about 24 inches apart when seedlings are 2-3 inches high.
Planting from Transplants in Fall:
- Select a location in full sun with good rich moist organic soil.
- Prepare the bed by turning the soil under to a depth of 8 inches. Level with a rake to remove clumps of grass and stones.
- Dig a hole for each plant large enough to amply accommodate the root ball. Space plants 2 feet apart in rows 3 feet apart.
- Carefully remove the plant from its pot and gently loosen the root ball with your hands to encourage good root development.
- Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
- Use the plant tag as a location marker.
- Thoroughly water and apply a light mulch layer on top of the soil (1-2 inches) to conserve water and reduce weeds.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating. Avoid disturbing the soil around the plants when weeding.
- Keep plants well watered during dry periods to promote rapid, uninterrupted growth.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area. While small, floating row covers will help to keep pests at bay.
Harvest and Preserving Tips
- Harvest heads when they become firm.
- Cut stems at soil level and remove outer leaves. Smaller heads will develop at base once the central head is harvested.
- Eat the heads raw or cooked.
- Store fall-harvested cabbage for several months if you store them at 40 degrees F in high humidity.
Common Disease Problems
Alternaria leaf spot: Small, round reddish brown spots with white to gray centers for on the upper surface of the leaves. The lesions may encircle the stems and cause wilt. This disease is worse in warm, wet or very humid weather. Burpee Recommends: Avoid getting water on the foliage. Remove infected plant parts and do not work around wet plants. Provide plenty of air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Clubroot: This causes plants to wilt in patches during the day, stunts their growth, and causes swollen or disfigured roots. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Improve drainage by reducing soil compaction. Do not work around plants when they are wet. Control weeds where the disease can overwinter.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation; if you plant in containers, thoroughly wash them in soapy water & rinse in a ten per cent bleach solution after use.
Downy Mildew: This fungus causes whitish gray patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Cabbage Looper: These worms are green with a white stripe on either side, about 1-1.5 inches long. They tunnel through the heads. Burpee Recommends: Hand pick. Floating row covers can help prevent their laying eggs on the plants.
Flea Beetles: These small hopping beetles feed on plant foliage and can spread disease. Burpee Recommends: Rotate crops with plants in a different plant family. Use floating row covers to prevent damage to young foliage.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Cabbage FAQs
Why is my cabbage not “heading”? Crowding, immaturity, or too much shade will delay or prevent the formation of a firm, large head.
Can I grow cabbage in containers? Yes, but only in a large container 24 inches deep and wide. Be sure to use a commercial container mix rather than garden soil.
My cabbage is blooming! Is it alright? Your cabbage has bolted probably because temperatures were too cold. Avoid planting too early.
Why is my cabbage splitting? The most likely explanation is that the plants have had too much water or too much nitrogen from fertilizing. Try mulching to control water levels.
Do I need to cook cabbage? Cabbage may be eaten cooked or raw.