Collard Greens in Zone 6B — Northeast

Collard greens are a fantastic addition to any Northeast garden. Their slightly bitter, earthy flavor transforms with a touch of frost, becoming sweeter and more palatable. Plus, they're incredibly versatile – you can sauté them, add them to soups, or even ferment them. Few things are as satisfying as harvesting your own greens on a cool autumn day after our short summer.

Our short growing season (around 183 days) and the occasional late spring or early fall frost can present challenges. But with careful timing and a little planning, you can enjoy a bountiful harvest of collard greens well into the fall. Early varieties recommended.

Starting collard greens indoors isn't always necessary, but it can give you a head start, especially if you're aiming for an early harvest. If you want to go this route, aim to start seeds indoors from mid-March through early April, about four weeks before you plan to transplant them outdoors. This is especially useful if you want to beat the heat.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist, and provide warmth (a heat mat can help) and plenty of light. Bottom watering is a great technique to avoid damping off. Remember, spring can be late here in the Northeast, so be patient and don't rush the process.

Transplant your collard green seedlings outdoors from mid-April through mid-May, once the danger of hard frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This will help them adjust to the cooler temperatures and stronger sunlight.

Space your plants 18-24 inches apart to allow for adequate growth. Keep an eye on the weather forecast – a late frost can still happen, so be prepared to cover your young plants if needed. Rocky New England soil is not ideal. Prepare the soil with compost.

Direct sowing collard greens is a perfectly viable option, and it can save you the trouble of starting seeds indoors. Sow seeds directly into the garden from early April through mid-July. Direct sowing lets you get a jump start on the season.

Prepare the soil by loosening it and amending with compost. Plant seeds about ½ inch deep and keep the soil consistently moist until germination. Thin seedlings to 18-24 inches apart once they emerge. Just be aware that direct-sown plants might take a little longer to mature than those started indoors.

Collard greens need consistent moisture to thrive, but they don't like to be waterlogged. Aim for about 1 inch of water per week, either from rainfall or irrigation. In the Northeast, we often get even rainfall throughout the summer, but there can be dry spells.

The "finger test" is a good way to check soil moisture: 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, especially given our moderate-to-humid summers. Overhead watering can encourage fungal diseases.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. A layer of mulch around your plants can help retain moisture and suppress weeds.

You can expect your first harvest of collard greens from mid-June through late October, depending on when you planted them and the specific variety. Collard greens are ready to harvest when the lower leaves are 10-12 inches long.

To harvest, simply snap off the outer leaves, leaving the top rosette intact. This will allow 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 until late fall.

As the first frost approaches (around mid-October here in the Northeast), you can harvest the entire plant or cover it with a frost blanket to extend the harvest a bit longer.

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

Cabbage Worms *What it looks like:* Smooth green caterpillars chewing irregular holes in leaves. You'll also see dark green droppings and white butterflies fluttering around. *What causes it:* These are the larvae of white cabbage butterflies. They can go through several generations during our warm months. *How to fix/prevent it:* Bt spray is your friend! Floating row covers are excellent for preventing the butterflies from laying eggs. Handpicking works, too. Plant thyme and sage nearby to deter them.

Aphids *What it looks like:* Clusters of tiny green, black, or white insects on stems and undersides of leaves. You might see sticky honeydew or distorted growth. *What causes it:* These sap-sucking insects reproduce rapidly, especially in warm weather. Ants often protect them. *How to fix/prevent it:* A strong spray of water can knock them off. Encourage ladybugs and lacewings. Insecticidal soap or neem oil can help with heavy infestations. Avoid over-fertilizing with nitrogen.

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:* They are moth larvae. *How to fix/prevent it:* Bt spray works well. Handpicking is also an option.

Downy Mildew *What it looks like:* Yellow patches on the upper leaf surface with fuzzy gray-purple growth underneath. Leaves eventually turn brown and die from the bottom up. *What causes it:* This is a fungal disease that thrives in cool, humid conditions. *How to fix/prevent it:* Remove affected leaves. Improve air circulation by spacing plants properly. Water at the base of the plants. Copper-based fungicides can help prevent it.

Northeast Specific Challenges: Our moderate heat and moderate-to-humid summers, along with even rainfall, can create ideal conditions for fungal diseases like downy mildew. Keep an eye on your plants and take preventative measures to minimize these issues. While deer may browse collard greens, they aren't typically as attracted to them as they are to other plants. However, if deer are a problem in your area, fencing or deer repellent might be necessary.

Companion planting can be beneficial for collard greens in several ways.

Good companions:

• Onion and Garlic: These alliums deter many pests, including aphids and cabbage worms.
• Beets: Beets help to loosen the soil, making it easier for collard greens to establish their roots.
• Potatoes: Potatoes help to improve soil drainage, which can be beneficial in our sometimes-wet Northeast climate.
• Dill: Dill attracts beneficial insects like ladybugs and lacewings, which prey on aphids and other pests.

Bad companions:

• Strawberry: Strawberries and collard greens compete for nutrients in the soil.
• Tomato: Tomatoes can attract pests that also affect collard greens, such as aphids and whiteflies.