Collard Greens in Zone 6B — Mid-Atlantic

Collard greens are a true Southern staple, and we can absolutely grow them here in the Mid-Atlantic! Their slightly bitter, earthy flavor is fantastic braised, sautéed, or even added to soups. Plus, they're incredibly productive, offering a long harvest window that extends well into the cooler months, giving you fresh greens when other crops are fading.

Our humid summers and sometimes unpredictable springs can present challenges. Deer pressure is real. But with a little planning and attention to timing, you can enjoy a bountiful collard green harvest. Our long 198-day growing season gives you plenty of opportunity to get it right.

Starting collard greens indoors in the Mid-Atlantic isn't strictly necessary, but it can give you a head start. If you want to get a jump on the season, sow seeds indoors from early to late March, about four weeks before you intend to transplant them outside.

Use seed trays filled with a good seed-starting mix. Keep them warm (around 70-75°F) and provide plenty of light – a sunny windowsill often isn't enough, so consider a grow light. Bottom watering helps prevent damping-off; set the tray in a shallow dish of water and let the soil absorb it. Our moderate spring weather makes direct sowing a viable option, so indoor starting is really only needed for the earliest possible harvest.

Transplant your collard green seedlings outdoors from early April through early May. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This prevents transplant shock.

Space the plants 18-24 inches apart in rows. Be mindful of our variable spring weather; if a late frost is predicted, be prepared to cover your young plants. Amending our clay soil with compost will improve drainage and provide essential nutrients.

Direct sowing collard greens is a perfectly acceptable method for Mid-Atlantic gardeners. Sow seeds from late March through late July for a continuous harvest.

Prepare the soil by loosening it and adding compost. Collard greens germinate best when the soil temperature is between 65-75°F. Plant seeds about ½ inch deep and space them 18-24 inches apart. Thin seedlings to the strongest plant once they emerge. The advantage of direct sowing is avoiding transplant shock, but you'll need to be vigilant about protecting young seedlings from pests.

Collard greens need consistent moisture to thrive, especially during our humid summers. Aim for about 1-1.5 inches of water per week, either from rainfall or irrigation.

Check the soil moisture regularly using the "finger test" – stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases in our humid climate.

Signs of underwatering include wilting leaves and slow growth. Overwatering, on the other hand, can lead to yellowing leaves and root rot. A layer of mulch, like straw or shredded leaves, helps retain soil moisture and suppress weeds. This is crucial in our Mid-Atlantic summers to keep the soil cool and evenly moist.

You can expect your first collard green harvest from early June through late November, depending on when you planted. The leaves are ready to harvest when they're 10-12 inches long and a deep green color.

Harvest the lower leaves first, leaving the top rosette intact to continue growing. This allows for a continuous harvest throughout the season. The flavor of collard greens actually sweetens after a light frost, so don't be afraid to leave them in the garden as late as possible.

As our first frost approaches in late October, harvest any remaining large leaves. You can even cover the plants with a blanket for a little extra protection to extend the harvest a bit longer.

Here are some common problems you might encounter with collard greens in the Mid-Atlantic:

Cabbage Worms

• What it looks like: Smooth green caterpillars chewing irregular holes in leaves, with dark green droppings. You might also see white butterflies fluttering around.
• What causes it: Larvae of white cabbage butterflies, which have multiple generations throughout our warm season.
• How to fix/prevent it: Bt spray is effective. Use floating row covers to prevent butterflies from laying eggs. Handpick caterpillars. 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: Rapidly reproducing, sap-sucking insects that thrive in warm weather. Ant colonies may protect them.
• How to fix/prevent it: Strong water spray to knock them off. Encourage ladybugs and lacewings. Use insecticidal soap for heavy infestations or neem oil. Avoid excess nitrogen fertilizer.

Cabbage Loopers

• What it looks like: Similar to cabbage worms, these are pale green caterpillars that move in a looping motion. They also chew holes in leaves.
• What causes it: The larvae of a moth. They are often present alongside cabbage worms.
• How to fix/prevent it: Handpicking, Bt spray, and row covers are effective. Attract beneficial insects like parasitic wasps.

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: An oomycete pathogen that spreads in cool, humid conditions via wind-carried spores. Our humid summers can make this a challenge.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation by spacing plants properly. Water at the base, never overhead. Consider copper-based fungicides for prevention, and plant resistant varieties.

Mid-Atlantic Specific Challenges: Our moderate-to-hot heat and humid summers create ideal conditions for many pests and diseases that affect collard greens. Consistent monitoring and prompt action are key to keeping your plants healthy. Deer pressure can also be a problem, so consider fencing or deer repellent.

Companion planting can help your collard greens thrive.

Good companions include onions and garlic, which deter pests with their strong scent. Beets and potatoes are also good choices, as they don't compete for the same nutrients in the soil. Dill attracts beneficial insects like ladybugs and lacewings, which prey on aphids.

Avoid planting collard greens near strawberries or tomatoes. Strawberries are susceptible to some of the same fungal diseases as collards, and tomatoes can attract pests that also attack collards.