Cabbage in Zone 7B — Southeast

Cabbage is a rewarding crop to grow in the Southeast. Freshly harvested cabbage has a sweetness that store-bought just can't match, and it's incredibly versatile in the kitchen. Whether you're making coleslaw, stir-fries, or braised cabbage, the flavor of your own homegrown harvest will shine.

Our long growing season here in Zone 7B gives us a great advantage. While we do have to contend with hot, humid summers and plenty of disease pressure, careful timing and smart gardening practices will help you bring in a successful cabbage crop. With our 235-day growing season, we can avoid the worst of the heat and humidity.

To get a jump start on your spring cabbage harvest, start your seeds indoors from mid January through early February. This gives the seedlings about 6 weeks to develop before it's time to transplant them outdoors. You'll need seed trays or small pots, a good quality seed starting mix, and a warm, bright location.

A heat mat can help speed up germination, and grow lights are essential for preventing leggy seedlings. Be sure to keep the soil consistently moist, and consider bottom watering to avoid damping off. Spring in the Southeast is moderate, so an early start indoors is a must.

Transplant your cabbage seedlings outdoors from early March through early April, once the danger of hard frost has passed. Before planting, it's crucial to harden off your seedlings. This means gradually exposing them to outdoor conditions over the course of a week.

Start by placing them in a sheltered spot for a few hours each day, gradually increasing the amount of time they spend outside. Plant your cabbage seedlings 12-18 inches apart in rows, giving them plenty of room to grow. Keep an eye on the weather; late cold snaps can happen, so be ready to cover them if needed.

Cabbage needs consistent moisture to thrive, but overwatering can lead to problems, especially with our humid Southeast climate. Aim for about 1 inch of water per week, either from rainfall or irrigation. Check the soil moisture by sticking your finger about 2 inches deep. If it feels dry, it's time to water.

During the hot summer months, you may need to water more frequently. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our humid conditions. Signs of underwatering include wilting leaves and stunted growth. Overwatering can cause yellowing leaves and root rot.

A layer of mulch around your cabbage plants will help retain moisture, suppress weeds, and regulate soil temperature. Pine straw or shredded leaves work well in our region.

You can expect to harvest your cabbage from mid May through early July, about 70 days after transplanting. The key sign of ripeness is a firm, solid head. Gently squeeze the cabbage head; it should feel dense and compact.

To harvest, use a sharp knife to cut the cabbage head at its base. Leave a few of the outer leaves intact to protect the cut surface. As the first frost approaches in early November, harvest any remaining heads, even if they aren't quite fully mature. They'll still be delicious!

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

Cabbage Worms

• What it looks like: Smooth green caterpillars on brassica leaves. Irregular holes chewed in leaves. Dark green droppings. White butterflies hovering around plants.
• What causes it: Larvae of white cabbage butterflies. Multiple generations per season in our warm climate.
• How to fix/prevent it: Bt spray is very effective. Floating row covers prevent egg laying. Handpick caterpillars. Interplant with aromatic herbs (thyme, sage). Encourage parasitic wasps.

Cabbage Loopers

• What it looks like: Pale green caterpillars that move in a looping motion. They chew large holes in leaves, often leaving behind the veins.
• What causes it: Similar to cabbage worms, these are the larvae of moths that lay eggs on brassica plants. They thrive in warm weather.
• How to fix/prevent it: Bt spray is effective. Handpicking can work for small infestations. Encourage beneficial insects like lacewings and parasitic wasps.

Splitting

• What it looks like: The cabbage head cracks open.
• What causes it: Inconsistent watering. Heavy watering after a dry spell causes the head to swell too quickly, leading to splitting.
• How to fix/prevent it: Maintain consistent soil moisture. Water regularly, especially during dry periods. Harvest cabbage as soon as it's mature to prevent over-ripening and splitting.

Clubroot

• What it looks like: Stunted growth, wilting in afternoon heat, yellowing leaves. Roots are swollen, distorted, and club-shaped when dug up.
• What causes it: Soil-borne pathogen (Plasmodiophora brassicae) that persists in soil for 10+ years. Favors acidic, wet soil.
• How to fix/prevent it: Raise soil pH to 7.0-7.2 with lime. Improve drainage. Rotate brassicas on a 7-year cycle. Remove and destroy infected plants (don't compost). Start transplants in sterile mix.

Southeast Specific Challenges: Our hot, humid summers create ideal conditions for fungal diseases and pests like cabbage worms. The wet-summer rainfall can also exacerbate splitting issues if watering isn't carefully managed. Be vigilant about monitoring your plants and take action quickly to prevent problems from escalating.

Companion planting can help your cabbage thrive in the Southeast. Green beans are good companions because they fix nitrogen in the soil, which benefits cabbage. Celery helps repel cabbage white butterflies, reducing the risk of cabbage worms.

Onions and dill can also deter pests. Potatoes are said to improve cabbage flavor. Avoid planting cabbage near tomatoes, strawberries, or peppers. These plants can compete for nutrients or attract pests that also affect cabbage.