Collard Greens in Zone 8B — Southeast

Collard greens are a Southern staple for a reason. They thrive in our long summer, providing a continuous harvest of nutritious leaves that are delicious braised, sautéed, or added to soups. Plus, there's nothing quite like the satisfaction of growing your own fresh greens, especially when they're as versatile and easy to prepare as collards.

While the Southeast's hot and humid summers can present challenges, with a good understanding of timing and a few preventative measures, you can easily grow a bountiful crop of collard greens. Our 255-day growing season gives you plenty of opportunity to get it right.

Starting collard greens indoors isn't essential in our climate, but it can give you a head start, especially for an early spring harvest. If you want to go this route, start your seeds indoors from early to late February, about four weeks before you plan to transplant them.

Use seed trays or small pots filled with a good seed-starting mix. Keep them warm (around 70-75°F) and provide plenty of light, either with a grow light or a sunny windowsill. Remember to bottom water your seedlings to encourage strong root growth and prevent damping off. Since spring can be moderate here, starting indoors gives you extra control.

Transplant your collard green seedlings outdoors from early March through early April, after the danger of any hard freezes has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Choose a location that gets full sun to partial shade, and space the plants 18-24 inches apart. Our weather can be unpredictable at this time of year, so keep an eye on the forecast and be prepared to cover your transplants if a late frost threatens.

Direct sowing is a perfectly viable option for growing collard greens in the Southeast, and it's often the easiest. You can direct sow from late February through late August, giving you a long window to get your crop in the ground.

Prepare your soil by loosening it and adding compost. Plant seeds about ½ inch deep and keep the soil consistently moist until they germinate. Thin seedlings to 18-24 inches apart. Direct sowing skips the transplant step, but remember you will have to stay on top of watering the seeds and young plants, especially during the hotter months.

Consistent watering is key to growing healthy collard greens in our hot, humid climate. While collards are more heat-tolerant than some other brassicas, they still need regular moisture, especially to produce tender, flavorful leaves.

During the spring and fall, when temperatures are milder and we get more consistent rainfall, you may only need to supplement with watering once or twice a week, providing about 1 inch of water each time. In the heat of summer, though, you'll likely need to water every day or every other day, especially if we're experiencing a dry spell.

Use the "finger test" to check the soil moisture: stick your finger about 2 inches into the soil near the base of the plant. If it feels dry, it's time to water. Water at the base of the plants rather than overhead to help prevent fungal diseases, which are common in our humid environment.

Signs of underwatering include wilting leaves and slow growth. Overwatering, on the other hand, can lead to root rot and yellowing leaves. Applying a layer of mulch around your plants can help retain moisture and suppress weeds. Pine straw or shredded leaves work well in our region.

You can expect your first harvest of collard greens about 75 days after planting. In the Southeast, this means you could be harvesting from early May through late November, depending on when you planted.

Harvest the lower leaves when they are 10-12 inches long. Simply snap or cut them off near the base of the plant, being careful not to damage the central rosette. Leaving the top rosette intact will allow the plant to continue producing new leaves throughout the season.

Collard greens actually taste sweeter after a light frost, so don't be afraid to leave them in the garden as temperatures start to drop in the fall. As our first frost approaches in mid- November, harvest any remaining leaves to enjoy.

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

Cabbage Worms

• What it looks like: Smooth green caterpillars chewing irregular holes in leaves, dark green droppings, and white butterflies flying around.
• What causes it: Larvae of white cabbage butterflies. They love our warm, long growing season and can have multiple generations.
• How to fix/prevent it: Bt spray is very effective and safe. Floating row covers will prevent the butterflies from laying eggs. You can also handpick the caterpillars and interplant with aromatic herbs like thyme and sage to deter them.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides, sticky honeydew residue, and curled or distorted new growth.
• What causes it: These sap-sucking insects reproduce rapidly, especially in warm weather. Ants often "farm" them for their honeydew.
• How to fix/prevent it: A strong spray of water will knock them off. Encourage ladybugs and lacewings, which are natural predators. Insecticidal soap works well for heavy infestations, and neem oil can be used systemically. Avoid over-fertilizing with nitrogen, which attracts aphids.

Cabbage Loopers

• What it looks like: Similar to cabbage worms, these are green caterpillars that feed on leaves, leaving ragged holes. They move in a looping motion.
• What causes it: These are the larvae of a moth, and they thrive in warm weather.
• How to fix/prevent it: Just like cabbage worms, Bt spray is effective, and handpicking is an option. Row covers can also help prevent the moths from laying eggs on your plants.

Downy Mildew

• What it looks like: Yellow patches on leaf tops with fuzzy gray-purple growth on the undersides. Leaves brown and die from the bottom up.
• What causes it: This fungal disease spreads in cool, humid conditions via wind-carried spores. It's a common problem in our region.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation by spacing plants properly. Water at the base of the plants, never overhead. Copper-based fungicides can be used preventatively.

Southeast Specific Challenges: Our hot and humid summers, combined with frequent afternoon thunderstorms, create the perfect environment for fungal diseases and pests like cabbage worms and aphids to thrive. Consistent monitoring and preventative measures are key to keeping your collard greens healthy and productive. Deer can also be a problem, so consider fencing or deer repellent if they are common in your area.

Companion planting can help your collard greens thrive. Plant onions and garlic nearby to deter pests. Beets and potatoes are also good companions, as they don't compete for the same nutrients. Dill attracts beneficial insects that prey on cabbage worms and other pests.

Avoid planting strawberries or tomatoes near your collard greens. Strawberries can attract slugs and snails, which can also damage your collards. Tomatoes can stunt the growth of collard greens.