Collard Greens in Zone 3B — Midwest

Collard greens are a nutritional powerhouse that thrive in our Midwest summers, offering a delicious, slightly bitter flavor that's fantastic braised, sauteed, or added to soups. The satisfaction of harvesting your own greens, especially after a long winter, is hard to beat.

While we deal with the occasional summer heat spells and unpredictable spring weather in the Midwest, collard greens are surprisingly adaptable. With a growing season of around 118 days, you have plenty of time to get a good harvest.

Starting collard greens indoors isn't essential, but it can give you a head start, especially if you're itching to get gardening after a long winter. If you want to go this route, aim to start your seeds indoors from mid-April through early May, about four weeks before you plan to transplant them outside.

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. Make sure to water from the bottom to encourage strong root growth and prevent damping-off. Given our moderate-to-late springs here in the Midwest, this can help you get a jump on the season.

Transplanting your collard greens seedlings outdoors should happen from mid-May through mid-June, after the risk of frost has passed. Before planting, it's crucial to harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

When transplanting, space your collard greens 18-24 inches apart in fertile soil. Keep an eye on the Midwest weather – a sudden cold snap can still happen, so be prepared to cover your young plants if necessary.

Direct sowing collard greens is a perfectly viable option for us here in the Midwest. The advantage is less fuss and no transplant shock. The downside is that you're relying on the weather cooperating for germination.

Sow seeds directly into the garden from early May through mid-June. Make sure the soil is warm and workable. Plant seeds about ½ inch deep, spacing them 18-24 inches apart.

Collard greens like consistent moisture, but they definitely don't want to be waterlogged, especially with our moderate-to-humid conditions during the summer. Aim to keep the soil evenly moist, not soggy.

During the hotter parts of the summer, check the soil moisture regularly using the finger test – stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Generally, collard greens need about 1 inch of water per week, either from rainfall or irrigation. Given our wet summers here in the Midwest, you might not need to water as often as you think.

Water at the base of the plants rather than overhead to minimize the risk of fungal diseases, which can be a problem in our humid climate. If the leaves start to wilt, it's a sign of underwatering. Yellowing leaves can indicate overwatering. Applying a layer of mulch around your collard greens helps retain moisture and suppress weeds, which is always a plus.

You can expect to start harvesting your collard greens from mid-July through late September, about 75 days after planting. Look for the lower leaves to be about 10-12 inches long.

To harvest, simply cut or snap off the outer leaves, leaving the top rosette intact. This allows the plant to continue producing new leaves throughout the season. Many gardeners in the Midwest find that the flavor of collard greens sweetens up after a light frost, so don't be afraid to leave them in the ground as long as possible.

As the first frost approaches in mid-September, you can either harvest all the remaining leaves or cover the plants to extend the harvest a little longer. Collard greens are quite hardy and can tolerate a light frost.

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 leaves. You might also see dark green droppings and white butterflies fluttering around. *What causes it:* These are the larvae of white cabbage butterflies. They can have multiple generations during our warm summers. *How to fix/prevent it:* Bt spray is very effective. Use floating row covers to keep the butterflies from laying eggs. Handpick the caterpillars when you see them. 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 or curled, 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 natural predators like ladybugs and lacewings. Use insecticidal soap for heavy infestations, or neem oil. Avoid over-fertilizing with nitrogen, as this attracts them.

Cabbage Loopers *What it looks like:* Similar to cabbage worms, but these caterpillars move with a distinctive "looping" motion. They also chew holes in leaves. *What causes it:* These are the larvae of a different type of moth. They are more common during warm, humid conditions. *How to fix/prevent it:* Similar to cabbage worms, Bt spray is effective. Floating row covers can help. Handpick them when you see them.

Downy Mildew *What it looks like:* Yellow patches on the tops of leaves, with fuzzy gray-purple growth on the undersides. Leaves turn brown and die, starting from the bottom of the plant. *What causes it:* This is a fungal disease that thrives in cool, humid conditions and spreads through wind-carried spores. *How to fix/prevent it:* Remove affected leaves immediately. Improve air circulation around the plants. Water at the base, never overhead. Copper-based fungicides can help prevent it.

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

Companion planting can give your collard greens a boost. Onions and garlic are great companions because their strong scent can deter pests. Beets and potatoes are also good choices, as they don't compete for the same nutrients. Dill attracts beneficial insects that prey on pests.

Avoid planting collard greens near strawberries or tomatoes. Strawberries compete for nutrients, and tomatoes can attract pests that also affect collards.