Collard Greens in Zone 5B — Midwest

Collard greens are a fantastic addition to any Midwest garden. They offer a unique, slightly bitter flavor that’s delicious in soups, stews, or simply sautéed. Plus, they're surprisingly cold-hardy, offering a welcome harvest well into the fall when other crops are fading.

Our Midwest weather can be unpredictable, and summer heat spells can be tough on some greens. But with proper timing and care, collards thrive here, giving you a long harvest window within our 168-day growing season.

Starting collard greens indoors gives you a head start, especially if you're aiming for an early harvest. If you want to do this, begin in late March through mid April, about four weeks before you plan to transplant them outside.

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 best. I like to bottom water my seedlings to encourage strong root growth and prevent damping off.

Given our moderate-to-late spring, starting indoors gives you a jump on the season, but direct sowing works well too.

Transplant your collard greens seedlings outdoors in late April through late May, after the risk of a hard frost has passed. Before transplanting, harden them off 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 forecast, as we can still get some unexpected cold snaps in the late spring.

Direct sowing collard greens is a simple and effective method, especially if you have fertile soil. Sow seeds mid April through mid July, once the soil has warmed up a bit.

Prepare the soil by loosening it and adding some compost. Plant seeds about ½ inch deep, spacing them 18-24 inches apart.

The advantage of direct sowing is that you avoid transplant shock, but you'll need to be diligent about thinning seedlings and protecting them from pests.

Collard greens need consistent moisture, especially during our summer heat spells. Aim for about 1-1.5 inches of water per week, whether it comes from rainfall or your garden hose.

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 moderate-to-humid climate.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. Mulching around your collard greens helps retain moisture and suppress weeds, which is especially helpful with our wet-summer rainfall.

You can expect your first harvest of collard greens in late June through mid October, about 75 days after planting. Look for leaves that are 10-12 inches long.

Harvest the lower leaves first, leaving the top rosette to continue growing. This allows for a continuous harvest throughout the season. Many gardeners, including myself, find that the flavor of collard greens sweetens after a light frost.

As the first frost approaches in early October, you can cover your plants to extend the harvest a bit longer.

Here are some common problems you might encounter with collard greens in the Midwest:

Cabbage Worms *What it looks like:* Smooth green caterpillars chewing irregular holes in leaves. You might also see dark green droppings and white butterflies fluttering around. *What causes it:* These are the larvae of cabbage butterflies, and we often get multiple generations during our warm summers. *How to fix/prevent it:* Bt spray is very effective. Floating row covers can prevent the butterflies from laying eggs. Handpicking caterpillars also works.

Aphids *What it looks like:* Clusters of tiny green, black, or white insects on stems and leaf undersides. You might also see sticky honeydew and curled or distorted new growth. *What causes it:* Aphids are sap-sucking insects that reproduce rapidly, especially in warm weather. *How to fix/prevent it:* A strong spray of water can knock them off. Encourage ladybugs and lacewings, which are natural predators. Insecticidal soap works well for heavy infestations.

Cabbage Loopers *What it looks like:* Similar to cabbage worms, but these are pale green caterpillars that move in a looping fashion. They also chew holes in leaves. *What causes it:* Cabbage loopers are another type of caterpillar that thrives in warm weather. *How to fix/prevent it:* Use Bt spray, handpick them, or use floating row covers.

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 is a fungal disease that spreads in cool, humid conditions. *How to fix/prevent it:* Remove affected leaves immediately. Improve air circulation. Water at the base of the plants. Copper-based fungicides can help prevent it.

Midwest Specific Challenges: Our moderate-to-hot summer heat, combined with moderate-to-humid humidity and wet-summer rainfall, can create ideal conditions for pests and diseases. Regular monitoring and prompt action are key to keeping your collard greens healthy.

Companion planting can really boost your collard greens in the Midwest garden.

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

Avoid planting collard greens near strawberries or tomatoes. Strawberries can be susceptible to similar fungal diseases, and tomatoes can stunt the growth of collards.