Collard Greens in Zone 4B — Great Plains

Collard greens are a Southern staple that surprisingly thrives even here in the Great Plains. Their slightly bitter, earthy flavor makes them incredibly versatile in everything from soups and stews to simple sautees. Plus, harvesting your own greens late into the season, even after a light frost, gives a real sense of accomplishment in our challenging climate.

Our 149-day growing season and extreme weather can be tough on many crops, but with careful timing and a little protection, you can absolutely enjoy a bountiful harvest of collard greens. We'll walk you through the best strategies to make it happen.

Starting collard greens indoors gives you a head start, especially important in our shorter growing season, particularly if you're further north in the Plains. Begin your seeds indoors late March through late April, about four weeks before you plan to transplant.

Use seed trays with a good seed-starting mix. Keep the soil consistently moist – bottom watering works great to prevent damping off. Ensure they get plenty of light, either from a sunny south-facing window or a grow light. Keep in mind that our spring weather is variable; indoor starting protects seedlings from late frosts and temperature swings.

Transplanting collard greens seedlings outdoors should happen early May through early June, once the danger of a hard frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space your plants 18-24 inches apart to allow for good air circulation. Keep an eye on the weather forecast; a sudden hailstorm or late frost can damage young plants. Wind protection is essential too, so consider planting in a sheltered spot or using windbreaks.

Direct sowing collard greens is definitely an option, and it can save you some time and effort. Sow seeds late April through early July, once the soil has warmed up to at least 60°F.

Prepare your soil by loosening it and adding compost. Plant seeds about ½ inch deep, spacing them 18-24 inches apart. Keep the soil consistently moist until the seedlings emerge. Direct sowing is convenient, but seedlings are more vulnerable to pests and weather fluctuations, so monitor them closely.

Collard greens need consistent moisture to produce tender, flavorful leaves, but they don't like soggy soil. In the Great Plains, that means paying close attention to watering, especially during our hot, dry summers.

A good rule of thumb is to water deeply once or twice a week, providing about 1-1.5 inches of water each time, depending on rainfall. Use the finger test: stick your finger about 2 inches into the soil; if it feels dry, it's time to water. Watering at the base of the plant is best to avoid wetting the leaves, which can encourage disease in our low-to-moderate humidity.

Watch for signs of underwatering, like wilting leaves, or overwatering, like yellowing leaves. A layer of mulch, like straw or wood chips, helps retain moisture and regulate soil temperature, which is crucial in our extreme temperature swings. Consistent watering results in the best tasting greens.

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

Harvest by cutting the outer leaves near the base of the plant, leaving the top rosette to continue growing. This allows for continuous harvesting throughout the season. The flavor of collard greens actually sweetens after a light frost, so don't be afraid to leave them in the garden a little longer.

As the first frost approaches in early October, harvest any remaining large leaves. You can blanch and freeze them for later use.

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

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, which can have multiple generations during our warm summers.
• How to fix/prevent it: Bt spray is very effective. Floating row covers prevent the butterflies from laying eggs. Handpicking the caterpillars is also an option. Interplanting with aromatic herbs like thyme and sage can help deter them.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides. 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.
• How to fix/prevent it: A strong spray of water can knock them off. Encourage ladybugs and lacewings, which are natural predators. Insecticidal soap or neem oil can be used for heavy infestations. Avoid excess nitrogen fertilizer, as it attracts them.

Cabbage Loopers

• What it looks like: Similar to cabbage worms, these are pale green caterpillars that move in a looping motion. They also chew holes in leaves.
• What causes it: These are the larvae of moths.
• 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 undersides. Leaves 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 immediately. Improve air circulation by spacing plants properly. Water at the base of the plant. Copper-based fungicides can be used for prevention.

Great Plains Specific Challenges: Our hot summers and variable rainfall can stress collard greens, making them more susceptible to pests and diseases. Consistent watering, good air circulation, and regular monitoring are key to keeping your plants healthy. Wind protection is also crucial to prevent leaf damage and plant stress.

Companion planting can really help your collard greens thrive in the Great Plains.

Good companions include onions and garlic, which deter pests with their strong scent. Beets improve soil health and don't compete for the same nutrients. Potatoes don't directly benefit collards, but they play well together and don't compete for resources. Dill attracts beneficial insects like ladybugs and lacewings, which prey on aphids and other pests.

Avoid planting collard greens near strawberries or tomatoes. Strawberries are susceptible to some of the same fungal diseases as collards, and tomatoes can attract pests that also bother collards.