Collard Greens in Zone 7A — Mid-Atlantic

Here in the Mid-Atlantic, collard greens are a garden staple for good reason. Their slightly bitter, earthy flavor transforms into something truly special after a kiss of frost, making them a perfect addition to soups, stews, or simply sautéed with garlic. Plus, the satisfaction of harvesting those big, beautiful leaves throughout the fall and even into early winter is hard to beat.

We definitely have our share of challenges here, from humid summers to hungry deer, but don't let that scare you off. With a 208-day growing season, we have plenty of time to get a great harvest of collard greens. Careful timing and a few preventative measures will keep your plants happy and productive.

Starting collard greens indoors isn't strictly necessary in our Zone 7A climate, but it can give you a head start, especially if you're eager for an early harvest. If you choose to start indoors, aim for early to late March, roughly four weeks before you plan to transplant them outside.

Use seed trays or small pots filled with seed-starting mix. Keep them warm and provide plenty of light, either from a sunny windowsill or a grow light. Bottom watering helps keep the leaves dry and prevents damping off – just set the tray in a shallow dish of water until the surface of the soil is moist. Our moderate spring weather usually means you can get away with direct sowing, but starting indoors is a good option if you want to ensure your harvest.

Once the danger of hard frost has passed—typically early April through early May—it's time to transplant your collard greens seedlings outdoors. Before planting them in the ground, be sure to harden them off. This means gradually exposing them to outdoor conditions for about a week.

Space your plants 18 to 24 inches apart to give them plenty of room to grow. Keep an eye on the weather forecast; those variable spring temperatures can sometimes bring a late frost, so be ready to cover your young plants if needed.

Direct sowing collard greens is a perfectly viable option in our Mid-Atlantic climate, and it's often the easiest method. You can sow seeds directly into the garden from late March through early August.

Prepare your soil by loosening it and mixing in some compost or well-rotted manure. Sow seeds about ½ inch deep and keep the soil consistently moist until they germinate. Thin seedlings to 18 to 24 inches apart once they have a few true leaves. Direct sowing is less work, but you might have to contend with pests a bit more than with transplants.

With our humid summers and fairly even rainfall, watering collard greens in the Mid-Atlantic requires a bit of finesse. While they aren't drought-tolerant, overwatering can be just as detrimental, especially with our heavy clay soils.

During the spring and fall, when temperatures are milder and rainfall is more frequent, you may only need to supplement with watering once or twice a week, aiming for about 1 inch of water per week. In the heat of summer, when temperatures can climb into the high 80s and humidity is high, you might need to water more frequently, especially if you're not getting regular rainfall. Use the finger test: stick your finger into the soil about 2 inches deep. 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. Look for signs of under-watering, like wilting leaves, or overwatering, like yellowing leaves. A layer of mulch around the base of your plants will help retain moisture and suppress weeds.

Here in Zone 7A, you can expect your first harvest of collard greens from early June through early November, about 75 days after planting. The best time to harvest is when the lower leaves are about 10 to 12 inches long.

To harvest, simply snap off the outer leaves, leaving the central rosette to continue growing. This allows for continuous production throughout the season. Don't be afraid to harvest regularly – it encourages new growth. As our first frost approaches in late October, don't panic! The flavor of collard greens actually sweetens after a frost, so you can continue harvesting even after a light freeze. You can even cover them to extend the harvest a bit longer.

Collard greens are generally easy to grow, but here in the Mid-Atlantic, we do face a few common problems:

Cabbage Worms *What it looks like:* Smooth green caterpillars chewing irregular holes in leaves, dark green droppings, and white butterflies fluttering around. *What causes it:* The larvae of those pretty white cabbage butterflies. They love our warm, humid summers. *How to fix/prevent it:* Bt spray is your best friend. Floating row covers can prevent the butterflies from laying eggs. Handpick the caterpillars if you see 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. *How to fix/prevent it:* A strong blast of water from the hose can knock them off. Encourage ladybugs and lacewings. Use insecticidal soap for heavy infestations.

Cabbage Loopers *What it looks like:* Similar to cabbage worms, but these caterpillars move in a looping motion. They also chew holes in the leaves. *What causes it:* These are another type of caterpillar that loves brassicas and our warm summers. *How to fix/prevent it:* Just like cabbage worms, Bt spray and handpicking are effective.

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:* A pathogen that spreads in cool, humid conditions – something we often experience in the spring and fall. *How to fix/prevent it:* Remove affected leaves immediately. Improve air circulation by spacing plants properly. Water at the base, never overhead.

Mid-Atlantic Specific Challenges: Our combination of moderate-to-hot heat, high humidity, and even rainfall can create ideal conditions for pests and diseases. Regular monitoring and preventative measures are key to keeping your collard greens healthy and productive.

Companion planting can be a great way to improve the health and productivity of your collard greens.

Good companions include onions and garlic, which help 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 that prey on pests like aphids and cabbage worms.

Avoid planting strawberries or tomatoes near your collard greens. Strawberries can attract slugs, which may then move on to your collards. Tomatoes can attract pests like aphids, and they also compete for the same nutrients in the soil.