Collard Greens in Zone 4B — Midwest

Collard Greens thrive in the Midwest, offering a slightly bitter but earthy flavor that's fantastic braised, sautéed, or added to soups. The plant handles our summer heat spells well, and you'll be harvesting fresh greens well into the fall – a real treat as the weather cools.

Our variable spring weather and occasional summer heat can be a challenge, but with a little planning, you can easily grow a healthy crop of Collard Greens. Our 138-day growing season gives you plenty of time to get a harvest, especially with these hardy plants.

Starting Collard Greens indoors is an option, but honestly, direct sowing often works just as well in the Midwest. If you want a head start, sow seeds indoors from early to late April, about 4 weeks before you'd like to put them in the garden.

Use seed trays with a good seed-starting mix and keep them in a warm spot with plenty of light – a sunny windowsill or under grow lights works well. Bottom watering helps keep the soil evenly moist without damping off the seedlings, which can be a problem in our humid springs.

Transplant your Collard Greens seedlings outdoors from early May through early June, after the risk of a hard frost has passed; we still need to watch for late frost in early May. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space them 18-24 inches apart in your garden. Keep an eye on the weather after transplanting. A sudden cold snap can stress young plants, so be ready to cover them if needed.

Direct sowing Collard Greens is a simple and effective method, especially if you're not in a huge rush. Sow seeds from late April through late June, anytime after the soil has warmed up a bit.

Prepare your soil by loosening it and adding some compost. Plant seeds about ½ inch deep and space them 18-24 inches apart, or sow them closer and thin later. Keep the soil consistently moist until the seedlings emerge.

Collard Greens need consistent moisture to produce tender, flavorful leaves, but don't overdo it, especially with our wet-summer rainfall. A good rule of thumb is to water deeply once or twice a week, providing about 1-1.5 inches of water each time.

Stick your finger about 2 inches into the soil near the base of the plant. If it feels dry, it's time to water. During summer heat spells, you might need to water more frequently.

Water at the base of the plants to avoid getting the leaves wet, which can encourage fungal diseases in our moderate-to-humid environment. Signs of underwatering include wilting leaves, while yellowing leaves can indicate overwatering. A layer of mulch, like straw or shredded leaves, helps retain moisture and suppress weeds – a win-win for Midwest gardens.

You can expect your first harvest of Collard Greens from early July through early October, about 75 days after planting. Look for lower leaves that are about 10-12 inches long. These are usually ready to pick first.

Harvest by cutting or snapping off the outer leaves near the base of the plant, leaving the top rosette to continue growing. This encourages continuous production throughout the season.

The flavor of Collard Greens actually sweetens after a light frost, so don't rush to pull up your plants in late September. Keep harvesting as long as possible, and you can even cover them lightly if a hard freeze threatens to extend your harvest even further.

Cabbage Worms

• What it looks like: You'll see smooth, green caterpillars munching on leaves, leaving irregular holes and dark green droppings behind. White butterflies fluttering around your plants are a sign they're laying eggs.
• What causes it: These are the larvae of cabbage butterflies, and they can go through multiple generations in our warm Midwest summers.
• How to fix/prevent it: Bt spray is very effective. You can also use floating row covers to prevent the butterflies from laying eggs in the first place. Handpicking the caterpillars is another option. Encourage beneficial insects like parasitic wasps by planting dill nearby.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and undersides of leaves. You might also notice sticky honeydew residue and curled or distorted new growth.
• What causes it: Aphids are sap-sucking insects that reproduce rapidly, especially in warm weather. Ants sometimes "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. Insecticidal soap works well for heavy infestations, and neem oil has systemic effects. Avoid over-fertilizing with nitrogen, as this attracts aphids.

Cabbage Loopers

• What it looks like: Similar to cabbage worms, but these caterpillars move in a looping motion. They chew large holes in leaves and can quickly defoliate your plants.
• What causes it: These are the larvae of a gray-brown moth. They thrive in warm weather and can be particularly problematic during summer heat spells.
• How to fix/prevent it: Use floating row covers to prevent moths from laying eggs. Bt spray is effective against young loopers. Handpick larger caterpillars. Encourage natural predators like birds and parasitic wasps.

Downy Mildew

• What it looks like: Yellow patches on the tops of leaves, with fuzzy gray-purple growth on the undersides. The leaves will eventually brown and die, starting from the bottom of the plant.
• What causes it: This is a fungal disease that spreads in cool, humid conditions via wind-carried spores. It's more common in spring and fall when temperatures fluctuate.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation around your plants by spacing them properly. Water at the base of the plants to avoid wetting the leaves. Copper-based fungicides can be used for prevention.

Midwest Specific Challenges: Our moderate-to-hot summers and moderate-to-humid conditions can create favorable conditions for pests and diseases like cabbage worms, loopers, and downy mildew. Regular monitoring and prompt action are key to keeping your Collard Greens healthy.

Good companions for Collard Greens include onions and garlic, as their strong scent can deter pests like cabbage moths. Beets and potatoes are also good choices, as they don't compete for the same nutrients in our fertile soil. Dill attracts beneficial insects that prey on common pests.

Avoid planting Collard Greens near strawberries or tomatoes. Strawberries can attract slugs that may also damage your greens, and tomatoes can stunt the growth of Collard Greens, limiting your harvest.