Brussels Sprouts in Zone 7B — Southeast

Brussels sprouts, often overlooked, are a real treat when you grow them yourself here in Zone 7B. Their nutty, slightly sweet flavor is so much better than what you find at the grocery store. Plus, they're incredibly versatile – roast them, shred them for salads, or sauté them with bacon. There's a real satisfaction in harvesting these little cabbages after nurturing them through our long summer.

Now, let's be honest, our hot and humid Southeast summers can present some challenges for cool-season crops. But with a little planning and attention to timing, you can absolutely grow Brussels sprouts successfully. Our 235-day growing season gives you a nice window to work with, either starting early for a summer harvest or planting later for a fall crop that benefits from a touch of frost.

Starting Brussels sprouts indoors is definitely the way to go here in the Southeast. Get your seeds going from late January through mid February, about six weeks before you want to put them in the ground. This gives them a head start before our summer heat kicks in.

Use seed trays or small pots filled with a good seed-starting mix. Keep them warm (around 70°F) and provide plenty of light. A simple shop light works great. Don't forget to water from the bottom to avoid damping off, especially with our moderate spring humidity.

Transplant your Brussels sprouts seedlings outdoors from mid March through early April, once the danger of a hard frost has passed. Before planting them out in the garden, be sure to harden them off for about a week. Gradually expose them to outdoor conditions, increasing the time each day.

Space the plants about 18-24 inches apart. They need plenty of room to grow. At transplant time, keep an eye on the weather. We can get some unexpected temperature swings in early spring, so be ready to cover them if a late frost threatens.

Watering is critical for Brussels sprouts, especially during our long, hot, and humid summers. Consistent moisture is key to developing those tight, delicious sprouts. If they dry out, you'll end up with loose, bitter sprouts that nobody wants to eat.

During the warmer months, check the soil moisture regularly. Stick your finger about two inches deep. If it feels dry, it's time to water. Aim for about 1-1.5 inches of water per week, depending on rainfall. With our wet-summer rainfall, you might not need to water as often as you think, but pay attention. Water at the base of the plants to avoid getting the leaves wet, which can encourage fungal diseases in our humid climate.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. Mulching around your plants with straw or pine straw helps retain moisture and suppress weeds, a definite win in our climate.

Brussels sprouts can get tall and top-heavy, especially when those sprouts start forming. And a strong afternoon thunderstorm wind can easily knock them over. Staking is a must in our region.

Use sturdy stakes, like bamboo or metal, and insert them into the ground near the plants when they reach about 2 feet tall. Tie the stalks loosely to the stakes with twine or plant ties. This will keep them upright and prevent them from breaking in the wind.

Pruning Brussels sprouts is pretty straightforward. As the sprouts develop up the stalk, remove the yellowing or damaged lower leaves. This improves air circulation and helps prevent disease, which is always a concern in our humid climate.

About 3-4 weeks before you plan to harvest, top the plant by cutting off the top set of leaves. This directs the plant's energy into the sprouts, encouraging them to plump up. As first frost approaches around early November, you can remove any remaining small leaves to encourage the sprouts to mature before the cold weather sets in.

Here in Zone 7B, you can expect your first Brussels sprouts harvest from mid June through late July if you started early, or later in the fall if you planted for a fall harvest. The sprouts are ready to pick when they're firm and tight, about 1-2 inches in diameter. Start harvesting from the bottom of the stalk and work your way up.

To harvest, simply twist or snap the sprouts off the stalk. Don't yank them, or you might damage the plant. The plant will continue to produce sprouts as you harvest, so keep checking them regularly. Many gardeners in the Southeast swear that Brussels sprouts taste even better after a light frost, so don't be afraid to leave them in the garden until early November.

Brussels sprouts can face a few challenges in our Southeast gardens, but don't let that discourage you. Here are some common problems and how to deal with them:

Aphids:

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer (it attracts them).

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.

Loose Sprouts from Heat:

• What it looks like: Sprouts that don't form tightly, are leafy, and have a bitter taste.
• What causes it: High temperatures, especially during sprout development. Our long summer heat can stress the plants.
• How to fix/prevent it: Choose heat-tolerant varieties. Provide consistent moisture. Plant for a fall harvest to avoid the worst of the summer heat. Provide afternoon shade.

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 and humid climate creates a perfect environment for fungal diseases. Make sure to provide good air circulation around your plants and avoid overhead watering. Japanese beetles can also be a nuisance, but handpicking them or using traps can help. And deer are always a concern, so consider fencing or deer repellent.

Companion planting can be a great way to improve your Brussels sprouts crop here in the Southeast. Green beans are a good choice because they fix nitrogen in the soil, which Brussels sprouts love. Celery helps repel cabbage moths, protecting your plants from cabbage worms. Onions and dill also deter pests. Potatoes can help break up our heavy clay soil, making it easier for Brussels sprouts roots to grow.

Avoid planting Brussels sprouts near tomatoes, strawberries, or peppers. These plants can attract pests and diseases that can also affect your Brussels sprouts.