Collard Greens in Zone 7A — Southeast

Collard greens are a Southern staple for a reason. Their slightly bitter, earthy flavor is delicious braised, sauteed, or even added to soups. Plus, they thrive in our long summer and even taste better after a touch of frost. You'll get a real sense of satisfaction harvesting your own fresh greens throughout the long growing season.

Don't let the humidity and potential for pests scare you off. With a little planning and attention to timing, you can easily grow a bumper crop of collards. Our 225-day growing season gives you plenty of time to get them established and enjoy multiple harvests.

Starting collard greens indoors is an option, but honestly, it’s not usually necessary in our climate. Our moderate spring gives you plenty of time for direct sowing. However, if you want a head start or are aiming for an exceptionally early harvest, go for it.

If you're starting indoors, begin in mid February through mid March, about four weeks before you plan to transplant. Use seed trays or small pots filled with a good seed-starting mix. Keep them warm and provide plenty of light – a grow light works great. And remember to water from the bottom to avoid damping off, which can be a problem with our humid conditions.

Transplant your collard green seedlings outdoors in late March through late April. This gives them a chance to establish before the real heat kicks in.

Before transplanting, harden off the seedlings by gradually exposing them to outdoor conditions for about a week. Space them 18-24 inches apart to give them plenty of room to grow. Keep an eye on the weather; we sometimes get a late cold snap, so be prepared to cover them if needed.

Direct sowing collard greens is the easiest method for most Southeast gardeners. You can sow seeds directly into the garden from mid March through early August.

Prepare the soil well, making sure it's loose and fertile. Collards prefer a soil temperature of at least 60°F for good germination. Sow seeds about ½ inch deep and thin seedlings to 18-24 inches apart once they emerge. Direct sowing gives you a continuous harvest throughout the long summer.

Collard greens need consistent moisture to produce tender, flavorful leaves. While they're more heat-tolerant than some other brassicas, they still need regular watering, especially during our hot and humid summers.

During the spring and fall, aim for about 1 inch of water per week, either from rainfall or irrigation. In the heat of summer, increase that to 1.5-2 inches per week. The finger test is a good way to check: stick your finger about 2 inches into the soil – if it feels dry, it's time to water. Always water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases in our humid climate.

Pay attention to your plants. Wilting leaves, even in the morning, indicate underwatering. Yellowing leaves can be a sign of overwatering, especially in our clay soil, which can retain too much moisture. A good layer of mulch, like pine straw or shredded leaves, will help retain moisture and suppress weeds, which is a big help in our climate.

You can expect your first harvest of collard greens in late May through mid November, about 75 days after planting. The best time to harvest is when the lower leaves are 10-12 inches long and a healthy green color.

To harvest, simply snap off the outer leaves, leaving the top rosette intact. This allows the plant to continue producing new leaves throughout the season. The flavor of collard greens actually sweetens after a frost, so don't be afraid to leave them in the garden as the weather cools down.

As the first frost approaches in early November, you can either harvest all the remaining leaves or cover the plants to protect them from the cold and extend the harvest a bit longer. Either way, you'll have enjoyed a long and productive season of fresh, homegrown collard greens.

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 are present, and you might see white cabbage butterflies flitting around. *What causes it:* These are the larvae of white cabbage butterflies. They thrive in our warm climate and can have multiple generations per season. *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. Interplanting with aromatic herbs like thyme and sage can help deter them. Encourage parasitic wasps to visit your garden, as they prey on cabbage worms.

Aphids *What it looks like:* Clusters of tiny, soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. 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 can knock them off. Encourage ladybugs and lacewings, which are natural predators. Use insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer, as it attracts aphids.

Cabbage Loopers *What it looks like:* Similar to cabbage worms but move in a looping fashion. They also chew holes in leaves, leaving behind dark green droppings. *What causes it:* These are the larvae of moths, and like cabbage worms, they thrive in our warm climate. *How to fix/prevent it:* Similar controls as for cabbage worms: Bt spray, handpicking, row covers, and encouraging beneficial insects.

Downy Mildew *What it looks like:* Yellow patches on leaf tops with fuzzy gray-purple growth on undersides. Leaves brown and die from the bottom up. *What causes it:* This is a fungal disease that spreads in cool, humid conditions via wind-carried spores. *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 for prevention. Plant resistant varieties if available.

Southeast Specific Challenges: The hot and humid summers in the Southeast create ideal conditions for fungal diseases like downy mildew. Regular monitoring, good air circulation, and proper watering techniques are essential. Japanese beetles can also be a nuisance, so be prepared to handpick them or use appropriate controls. Deer pressure can also be high, so consider fencing or deer-resistant sprays.

Good companions for collard greens include onions and garlic. Their strong scent deters many pests that bother collards. Beets and potatoes also make good companions as they don't compete for the same nutrients. Dill attracts beneficial insects like ladybugs and lacewings, which prey on aphids and other pests.

Avoid planting collard greens near strawberries or tomatoes. Strawberries can attract slugs and snails, which can also damage collards. Tomatoes can harbor diseases that can spread to collards.