Cabbage in Zone 7B — Mid-Atlantic

Cabbage is a rewarding crop to grow in the Mid-Atlantic. Its crisp texture and mild flavor make it a versatile addition to slaws, stir-fries, and soups, perfect for enjoying the flavors of our four seasons. There's nothing quite like the satisfaction of harvesting a tightly packed head of cabbage that you nurtured from a tiny seed right here in your own garden.

While we do face challenges like humid summers and variable spring weather here in Zone 7B, careful timing and attention will lead to a successful cabbage harvest. Our 214-day growing season gives you a good window to grow both spring and fall crops. With a bit of planning, you can enjoy fresh cabbage from your garden for months.

Starting cabbage indoors is the way to go for a spring harvest in the Mid-Atlantic. Begin sowing your seeds from late January through mid February, about six weeks before you plan to transplant them outside. Use seed trays or small pots filled with a good seed-starting mix.

Keep the soil consistently moist (but not soggy) and provide warmth, ideally around 70°F, until germination. Bottom watering helps prevent damping off; set the seed tray in a shallow dish of water and let the soil absorb the moisture from the bottom. Once the seedlings emerge, provide plenty of light, either from a sunny window or a grow light. Our moderate spring weather gives you time to get strong seedlings ready for transplanting.

Transplant your cabbage seedlings outdoors from mid March through mid April, once the risk of a hard freeze has passed. Before transplanting, harden off the seedlings by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade and increase the time and sunlight each day.

Space the seedlings 12-18 inches apart in rows that are 2-3 feet apart. Choose a spot that gets full sun (6-8 hours a day). Be prepared to cover the young plants if we get an unexpected cold snap, as our spring weather can be unpredictable.

Cabbage needs consistent moisture to thrive, but overwatering can be just as detrimental, especially with our humid summers. Aim to keep the soil evenly moist, but not waterlogged. Stick your finger about two inches deep into the soil; if it feels dry, it's time to water.

During the spring growing season, aim for about 1 inch of water per week, either from rainfall or irrigation. In the hotter, more humid summer months, you might need to increase that to 1.5 inches per week, depending on rainfall. Water at the base of the plants rather than overhead to avoid promoting fungal diseases in our humid climate. Mulching around your cabbage plants with straw or shredded leaves helps retain moisture and suppress weeds.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. Adjust your watering schedule based on the weather conditions and how quickly the soil dries out. Our even rainfall pattern generally helps, but be ready to supplement during dry spells.

You can expect your first cabbage harvest from late May through mid July, about 70 days after transplanting, depending on the variety. The best way to tell if a cabbage head is ready to harvest is to gently squeeze it. It should feel firm and solid. Also, make sure the head has reached the full size expected for its variety.

To harvest, use a sharp knife to cut the cabbage head at its base, leaving the outer leaves intact. If you leave the base and some outer leaves, the plant may produce smaller side heads later in the season, giving you a bonus harvest. As our first frost approaches in early November, harvest any remaining cabbage heads, even if they aren't fully mature. They'll still be tasty in soups and stews.

Here are a few common problems you might encounter with cabbage in the Mid-Atlantic:

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 warm climates. *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:* Similar to cabbage worms, but these caterpillars move with a distinctive looping motion. They also chew holes in leaves. *What causes it:* Cabbage looper moths lay eggs on the underside of leaves. *How to fix/prevent it:* Similar to cabbage worms, use Bt spray, floating row covers, handpicking, and encourage beneficial insects.

Splitting *What it looks like:* The cabbage head cracks or splits open. *What causes it:* Inconsistent watering, especially heavy watering after a dry spell. The head grows too quickly and the outer leaves can't keep up. *How to fix/prevent it:* Provide consistent moisture throughout the growing season. Mulch around the plants to retain moisture. If heavy rain is expected after a dry spell, consider partially harvesting the cabbage by cutting some of the roots to slow down growth.

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.

*Mid-Atlantic Specific Challenges:* Our moderate-to-hot summers and humid conditions can exacerbate pest and disease problems on cabbage. Regularly inspect your plants and take action quickly to prevent issues from getting out of hand. The even rainfall can be a blessing, but make sure you're monitoring soil moisture to avoid overwatering, especially in clay soil.

Companion planting can help your cabbage thrive in the Mid-Atlantic. Green beans fix nitrogen in the soil, benefiting cabbage's growth. Celery helps to deter cabbage white butterflies, reducing cabbage worm infestations. Onions and dill also repel cabbage pests with their strong scent. Potatoes don't directly benefit cabbage, but they don't compete for nutrients and can help break up heavy clay soil.

Avoid planting cabbage near tomatoes, strawberries, and peppers. Tomatoes and peppers compete for the same nutrients, and strawberries are susceptible to diseases that can spread to cabbage.