Collard Greens in Zone 6B — Midwest

Collard greens are a fantastic addition to any Midwest garden. Their slightly bitter, earthy flavor is delicious in soups, stews, or even sautéed as a side dish. Plus, they're incredibly versatile in the kitchen, thriving in the summer heat and even tasting sweeter after a light frost, making them a true Midwest garden staple.

While our Midwest weather can be unpredictable with its variable spring and summer heat spells, collard greens are surprisingly resilient. With a growing season of around 183 days, you have plenty of time to get a good harvest. Proper timing is key, but you'll find they’re a rewarding crop for our fertile soil.

Starting collard greens indoors is an option, especially if you're eager to get a head start on the season. Sow seeds indoors from mid-March through early April, about four weeks before you plan to transplant them outdoors. This can be helpful, but honestly, direct sowing often works just as well here in the Midwest.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist by bottom watering – set the tray in a shallow dish of water and let the soil absorb the moisture from the bottom. Place the trays in a warm location and provide plenty of light, either from a sunny window or a grow light. With our moderate-to-late springs, this gives you a little insurance.

Transplant your collard greens seedlings outdoors from mid-April through mid-May, after they've developed a few sets of true leaves. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind.

Choose a spot in your garden with full sun to partial shade and space the plants 18-24 inches apart. Keep an eye on the weather forecast; our variable spring means there's always a chance of a late frost. If a frost is predicted, cover the seedlings with row covers or blankets to protect them.

Direct sowing collard greens is a simple and effective way to grow them in the Midwest. Sow seeds directly into the garden from early April through mid-July. This gives you flexibility for succession planting and a continuous harvest.

Prepare the soil by loosening it and amending with compost. Sow seeds about ½ inch deep and space them 18-24 inches apart. Keep the soil consistently moist until the seedlings emerge. A pro of direct sowing is not having to disturb the roots. A con is the seeds are susceptible to pests.

Consistent watering is key for growing healthy collard greens in the Midwest. Aim to keep the soil evenly moist, but not waterlogged. The "finger test" is a good way to check: stick your finger into the soil about two inches deep. If it feels dry, it's time to water.

During the warmer months, especially during our summer heat spells, collard greens will need about 1 inch of water per week, either from rainfall or irrigation. Water at the base of the plants rather than overhead to minimize the risk of fungal diseases, which can be a concern with our moderate-to-humid summers.

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 around the plants can help retain moisture in our fertile soil and suppress weeds.

You can expect your first harvest of collard greens from mid-June through late October, about 75 days after planting. The best time to harvest is when the lower leaves are 10-12 inches long.

To harvest, simply snap off the outer leaves, leaving the top rosette of leaves intact. This allows the plant to continue producing new leaves throughout the season. Collard greens are known to sweeten after a frost, so don't be afraid to leave them in the garden a little longer as the weather cools.

As the first frost approaches in mid-October, harvest any remaining leaves. You can blanch and freeze them for later use, or add them to soups and stews for a hearty, homegrown meal.

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

Cabbage Worms *What it looks like:* Smooth green caterpillars chewing irregular holes in the leaves. You might also see dark green droppings and white butterflies fluttering around. *What causes it:* The larvae of white cabbage butterflies, which can have multiple generations during our warm summers. *How to fix/prevent it:* Use Bt spray, which is very effective. Floating row covers can prevent the butterflies from laying eggs. Handpick caterpillars whenever you see them, and interplant with aromatic herbs like thyme and sage to deter the butterflies.

Aphids *What it looks like:* Clusters of tiny insects (green, black, or white) on stems and leaf undersides. You might also notice sticky honeydew residue and curled or distorted new growth. *What causes it:* These sap-sucking insects reproduce rapidly, especially in warm weather. Ants may even "farm" them for honeydew. *How to fix/prevent it:* A strong spray of water can knock them off. Encourage ladybugs and lacewings, which are natural predators. Use insecticidal soap for heavy infestations, or neem oil. Avoid excess nitrogen fertilizer, which attracts aphids.

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 the larvae of moths. They thrive in warm weather. *How to fix/prevent it:* Use Bt spray, handpick them, and use row covers. Encourage birds to visit your garden, as they will eat the loopers.

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:* A pathogen that spreads in cool, humid conditions via wind-carried spores. *How to fix/prevent it:* Remove affected leaves immediately. Improve air circulation by spacing plants properly. Water at the base of the plants, never overhead. Copper-based fungicides can be used for prevention.

Midwest Specific Challenges: Our moderate-to-hot heat and moderate-to-humid summers can create ideal conditions for both pests and diseases. Regular monitoring and proactive measures are essential for keeping your collard greens healthy and productive.

Companion planting can be very helpful for collard greens in the Midwest. Plant onions and garlic nearby to deter pests. Beets and potatoes are also good companions, as they don't compete for the same nutrients in our fertile soil. Dill attracts beneficial insects that prey on cabbage worms and aphids.

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