Copenhagen Market Cabbage

Cabbages are heavy feeders and thus prefer rich, fertile soil with ample amounts of nitrogen, phosphorus, potassium and boron. Cabbage has a shallow, dense root system that makes it prone to moisture fluctuations and damage by cultivation. For best results, mulch plants with straw, newspaper or other natural materials. Cabbage prefers full sun, but can tolerate some light shade, especially in very warm climates.

Start seed indoors 6-8 weeks before last frost.  Sow seeds 1/4" deep in sterile seed starting media.  Germination will occur in approximately 5 days.  Fall cabbages can be started indoors approximately 3 months before last frost or direct seeded in mid-summer.  Floating row covers are recommended to protect late-planted seedlings from flea beetles.

To transplant cabbage, wait until the seedlings are 4-6 weeks old and have at least two sets of true leaves. Dig holes in the prepared soil about 18 inches apart and deep enough to accommodate the root balls of the seedlings. Place a generous amount of well-aged compost or a teaspoon of 10-10-10- fertilizer into the bottom of the hole and mix with the soil at the bottom. Gently remove the seedlings from their containers, being careful not to damage the roots, and place them in the holes. Backfill the holes with soil and water the plants thoroughly. Keep the soil moist but not waterlogged and provide shade as needed for the first few days to prevent transplant shock. Fertilize regularly and keep soil consistently moist.

Insect Pests

Very young direct-seeded plants are susceptible to flea beetles. Otherwise, the predominant threat to cabbages is the cabbage moth caterpillar. Floating row covers and biological controls like Bacillus thuringiensis (Bt) are very effective at controlling caterpillar damage.

Diseases & Other Problems

Although uncommon, cabbage is susceptible to several fungal and bacterial diseases, including black rot, clubroot, downy mildew, and fusarium yellows. These diseases can cause stunted growth, yellowing of leaves, wilting, and premature death of the plant. In addition to diseases, cabbage can also be affected by nutrient deficiencies, such as a lack of nitrogen or boron, and environmental stresses like heat or drought. To prevent and manage these problems, it's important to remove crop residue in the fall and use proper tillage and/or crop rotation, as well as provide proper soil nutrition and irrigation. Early detection and intervention are key to controlling diseases and other issues in cabbage. Additionally, one must be careful when cultivating near cabbage as the roots are shallow and delicate. Mulching around the base of the plant will reduce the need for soil disturbance and keep the soil consistently moist during dry spells.

To harvest cabbage, cut the head at the base of the plant with a sharp knife. If the plant has loose leaves, you can also harvest these by cutting the outer leaves at the base of the plant. Cabbage can be stored in the refrigerator for several weeks, or in a cool, dry place for longer periods. To store cabbage, remove any damaged or loose leaves and wrap the head tightly in plastic wrap or a plastic bag to prevent moisture loss. Alternatively, you can ferment cabbage into sauerkraut, which can be stored for several months in the refrigerator or a cool, dark place.

CONSIDERATIONS:

Cabbages are biennial plants that flower and produce seeds in the second year of growth. If you live in a climate with harsh winters, it is necessary to dig plants and bring them in during the coldest months before replanting in the spring. Some growers cut an "X" in the head to facilitate the emergence of the flower stalk. Once flowering begins, it is necessary isolate the plants in order to prevent cross-pollination with other related plants such as cauliflower, broccoli, and kale. Cross-pollination can result in undesirable traits in the offspring, affecting their taste, texture, and appearance. To prevent cross-pollination, you can either plant different crops in separate areas or use physical barriers such as nets or cages to protect the plants (pollinators will need to be introduced in this scenario).

HARVESTING SEED:

To harvest cabbage seeds, allow the plant to fully mature and form seed pods. The seed pods will turn brown and dry when they are ready for harvesting. Cut the seed stalks from the plant and place them in a dry and well-ventilated area for further drying, until the pods split open and release the seeds. Once the seeds are fully dried, separate them from the pods and store them in a cool and dry place until you are ready to plant them.

SEED LONGETIVITY:

Cabbage seeds can remain viable for up to 5 years if stored properly in a cool, dry, and dark place.