Cabbage in Zone 6B — Midwest

Cabbage is a fantastic crop for the Midwest garden, offering a satisfying crunch and mild flavor that's delicious raw in slaws or cooked in comforting dishes. It thrives in our fertile soil and delivers a rewarding harvest, whether you're making sauerkraut or enjoying a simple side of sauteed cabbage.

The Midwest weather can be unpredictable, with variable springs and the occasional summer heat spell. But with careful timing and attention, you can easily grow beautiful heads of cabbage within our 183-day growing season.

Starting cabbage indoors gives you a head start in our moderate-to-late spring. Begin sowing seeds from mid February through early March, about six weeks before you plan to transplant them outdoors. Use seed trays filled with a good seed-starting mix.

Keep the trays in a warm location, around 70°F, and provide plenty of light – a grow light works wonders, especially in those early spring weeks when sunlight can be scarce. Bottom watering is a great way to keep the soil consistently moist without disturbing the delicate seedlings.

Transplant your cabbage seedlings outdoors from early to late April, after they've developed several true leaves. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Midwest weather.

Space the plants 12-18 inches apart in a sunny spot with fertile soil. Keep an eye on the forecast – we sometimes get a late frost that can nip young plants, so be ready to cover them if needed.

Cabbage needs consistent moisture to thrive, but overwatering can be just as harmful as underwatering, especially with our wet-summer rainfall. Aim to keep the soil consistently moist, not soggy. A good rule of thumb is to water when the top two inches of soil feel dry to the touch – the "finger test."

In general, cabbage needs about 1-1.5 inches of water per week, either from rainfall or irrigation. Water at the base of the plants to avoid wetting the leaves, as our moderate-to-humid summers can make them susceptible to fungal diseases. Signs of underwatering include wilting leaves and stunted growth, while yellowing leaves can indicate overwatering.

Mulching around your cabbage plants with straw or shredded leaves helps retain moisture, suppress weeds, and regulate soil temperature. This is especially helpful during those summer heat spells we sometimes get.

You can expect your first cabbage harvest from early June through late July, about 70 days after transplanting. The best indicator of ripeness is the firmness of the head. When you squeeze it, it should feel solid and dense.

Harvest by cutting the head off at the base with a sharp knife. If a hard frost is approaching in mid- October, harvest any remaining heads, even if they aren't quite fully mature. They can still be used, though they might not store as long.

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

Cabbage Worms *What it looks like:* Smooth green caterpillars eating brassica leaves, leaving irregular holes and dark green droppings. You might also see white butterflies fluttering around. *What causes it:* Larvae of white cabbage butterflies. They can have multiple generations in our warm summer. *How to fix/prevent it:* Bt spray is very effective. Floating row covers prevent the butterflies from laying eggs. You can also handpick the caterpillars. Interplant with aromatic herbs like thyme and sage to deter them and encourage parasitic wasps.

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:* Cabbage looper moths lay eggs on cabbage and related plants. *How to fix/prevent it:* Bt spray works well on loopers too. Handpicking and row covers are also effective.

Splitting *What it looks like:* The cabbage head cracks open. *What causes it:* Inconsistent watering. A sudden heavy rain after a dry spell is a common culprit in our region. *How to fix/prevent it:* Maintain consistent soil moisture. Mulch helps. If a heavy rain is predicted after a dry period, consider harvesting heads that are close to maturity.

Clubroot *What it looks like:* Stunted growth, wilting during the afternoon heat, and yellowing leaves. When you dig up the plant, the roots are swollen, distorted, and club-shaped. *What causes it:* A soil-borne pathogen (Plasmodiophora brassicae) that thrives in acidic, wet soil. It can persist in the soil for many years. *How to fix/prevent it:* Raise the soil pH to 7.0-7.2 with lime. Improve drainage to avoid waterlogged conditions, which encourage the disease. Rotate brassicas on a 7-year cycle. Remove and destroy infected plants (don't compost them). Start transplants in sterile mix to avoid introducing the pathogen.

Midwest Specific Challenges: Our moderate-to-hot summer heat and moderate-to-humid humidity can encourage pests and diseases. Consistent monitoring and prompt action are key. Wet-summer rainfall makes consistent watering tricky, so good drainage and careful observation are essential.

Companion planting can help your cabbage thrive in the Midwest. Green beans are great companions because they fix nitrogen in the soil, which cabbage loves. Celery is said to deter cabbage white butterflies. Onions and dill also deter pests. Potatoes are good neighbors, as they don't compete for the same nutrients.

Avoid planting cabbage near tomatoes, strawberries, or peppers. Tomatoes and peppers can stunt cabbage growth. Strawberries have similar nutrient needs and can compete with cabbage.