Cabbage in Zone 6A — Southeast

Cabbage is a fantastic crop for Southeast gardens. Its crisp texture and mild flavor make it a versatile addition to slaws, stir-fries, and roasted dishes. The satisfaction of harvesting a tightly packed head of cabbage that you've nurtured through our sometimes unpredictable weather is truly rewarding.

While our hot and humid summers can present challenges with disease pressure, the long 198-day growing season in Zone 6A allows us to get a jump start on cabbage in early spring for a summer harvest. Careful timing and attention to watering will set you up for success.

Starting cabbage indoors gives you a head start, especially crucial for a spring harvest in our region. Begin sowing your cabbage seeds indoors from early to late February, roughly six weeks before you intend to transplant them outside. Use seed trays or small pots filled with a good seed-starting mix.

Keep the soil consistently moist, and consider bottom watering to prevent damping-off, which can be a problem in our humid conditions. Place the trays in a warm location, ideally around 70°F, and provide plenty of light – a grow light works great, especially with the moderate spring sunshine we often see.

Transplant your cabbage seedlings outdoors from late March through late April, after they’ve developed several true leaves. Before planting, harden off the seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sunlight, wind, and temperature fluctuations.

Space the plants 12-18 inches apart to allow for proper head development. The weather during this time can be variable, so keep an eye on the forecast and be prepared to cover the seedlings if a late frost threatens.

Cabbage needs consistent moisture, especially during head formation, but overwatering in our humid climate can lead to problems. Aim for about 1 inch of water per week, either from rainfall or irrigation. Use the "finger test" – if the top 2 inches of soil feel dry, it's time to water.

Water deeply at the base of the plant, rather than overhead, to minimize the risk of fungal diseases that thrive in our humid conditions. During our hot summer months, you might need to water more frequently, especially if we experience a dry spell between our usual afternoon thunderstorms.

Signs of underwatering include wilting leaves and stunted growth, while overwatering can cause yellowing leaves and root rot. A layer of organic mulch, like straw or shredded leaves, helps retain moisture, suppress weeds, and regulate soil temperature, which is especially helpful during our long, hot summer.

Your first cabbage harvest should be ready from early June through late July, about 70 days after transplanting. The key indicator of ripeness is the firmness of the head. Gently squeeze the cabbage head; it should feel solid and dense. Also, make sure it has reached the full size expected for the variety you're growing.

To harvest, use a sharp knife to cut the cabbage head at its base, leaving a few outer leaves intact. This can sometimes encourage the plant to produce smaller side shoots, giving you a small second harvest later on.

As our first frost approaches in late October, harvest any remaining cabbage heads, even if they're not quite fully mature. They'll still be perfectly edible, especially in cooked dishes.

Here are some common problems you might encounter growing cabbage in the Southeast:

Cabbage Worms

• What it looks like: Smooth green caterpillars chewing irregular holes in leaves, with dark green droppings present. You might also see white cabbage butterflies fluttering around.
• What causes it: The larvae of those pretty white cabbage butterflies. They can have multiple generations throughout our long, warm season.
• How to fix/prevent it: Bt (Bacillus thuringiensis) spray is very effective. Floating row covers are great for preventing the butterflies from laying eggs in the first place. You can also handpick the caterpillars. Interplanting with aromatic herbs like thyme and sage can help deter them, and attracting parasitic wasps is beneficial.

Cabbage Loopers

• What it looks like: Similar to cabbage worms, these are pale green caterpillars that move in a looping motion. They also chew holes in leaves.
• What causes it: Another type of caterpillar that thrives in our warm weather.
• How to fix/prevent it: Similar to cabbage worms, use Bt spray, handpick, and encourage beneficial insects. Row covers are effective for prevention.

Splitting

• What it looks like: The cabbage head cracks open, often after a heavy rain.
• What causes it: Inconsistent watering. The head grows rapidly after a period of drought, causing it to split.
• How to fix/prevent it: Maintain consistent soil moisture. Mulching helps. If heavy rain is expected after a dry spell, consider making a shallow cut on the side of the head to relieve pressure.

Clubroot

• What it looks like: Stunted growth, wilting in the afternoon heat, and yellowing leaves. When you dig up the plant, the roots are swollen, distorted, and club-shaped.
• What causes it: A soil-borne pathogen (Plasmodiophora brassicae) that can live in the soil for over 10 years. It loves acidic, wet soil.
• How to fix/prevent it: Raise the soil pH to 7.0-7.2 with lime. Improve drainage. Rotate brassicas (cabbage, broccoli, cauliflower, etc.) on a 7-year cycle. Remove and destroy infected plants (don't compost them!). Start transplants in a sterile mix.

Southeast Specific Challenges: Our hot, humid summers and wet-summer rainfall create ideal conditions for fungal diseases and pest infestations. Good air circulation, proper watering techniques, and vigilant monitoring are essential for growing healthy cabbage in this region. Japanese beetles can also be a nuisance, so be prepared to handpick them or use appropriate traps.

Companion planting can be a great way to improve your cabbage crop in the Southeast. Green beans are a good choice because they fix nitrogen in the soil, which benefits cabbage growth. Celery is also helpful, as its scent can deter cabbage moths. Onions and dill are other beneficial companions, as they can repel pests like aphids and cabbage worms. Potatoes can also be planted nearby, as they don't compete for the same nutrients.

Avoid planting cabbage near tomatoes, strawberries, or peppers. Tomatoes can stunt the growth of cabbage, while strawberries and peppers are susceptible to similar soil-borne diseases, potentially increasing disease pressure in your garden.