Swiss Chard in Zone 6A — Midwest

Swiss chard is a real workhorse in the Midwest garden. It's delicious sauteed, adds beautiful color to soups, and keeps producing even when the summer heat spells make other greens wilt. Plus, the colorful stems add a touch of beauty to your vegetable patch!

Our Midwest weather can be unpredictable, with those variable springs and occasional summer scorchers. But with a little attention to timing, you can easily grow Swiss chard throughout our 178-day growing season.

Starting Swiss chard indoors isn't essential, but it can give you a jump start, especially if you're eager for an early harvest. If you want to go this route, aim to sow seeds mid-March through early April.

Use seed trays or small pots filled with a good seed-starting mix. Keep them warm and provide plenty of light – a grow light works wonders, especially with our moderate-to-late spring. Don't forget to water from the bottom to prevent damping off.

Transplant your Swiss chard seedlings outdoors mid-April through mid-May, after they've developed a few 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.

When transplanting, space the plants 8-12 inches apart in fertile soil. Keep an eye on the forecast – a late frost can still happen, so be prepared to cover your young plants if needed.

Direct sowing is a straightforward way to grow Swiss chard, and it works well in our Midwest climate. Sow seeds early April through early August for a continuous harvest.

Prepare your soil by loosening it and adding compost. Sow seeds about ½ inch deep, spacing them 8-12 inches apart. Keep the soil consistently moist until the seedlings emerge. Direct sowing is a great option if you have good soil and want to avoid the extra step of transplanting.

Swiss chard appreciates consistent moisture, but it doesn't like to be waterlogged – a common issue with our wet-summer rainfall. Aim for moderate watering throughout the growing season. Feel the soil about 2 inches deep; if it's dry, it's time to water.

During the hotter parts of the summer, especially during those summer heat spells, your chard might need about an inch of water per week. Water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases in our moderate-to-humid climate. Overwatering can lead to yellowing leaves, while underwatering will cause wilting.

A good layer of mulch can help retain moisture and keep the soil cool. Straw or shredded leaves work well and are readily available in the Midwest.

You can expect your first harvest of Swiss chard late May through late October, about 55 days after planting. Look for outer stalks that are 8-12 inches long. The colorful stems are a good indicator that they're ready to pick.

To harvest, simply cut the outer stalks at the base of the plant, leaving the inner leaves to continue growing. This encourages continuous production throughout the season. As our first frost approaches in mid-October, harvest any remaining large leaves to prevent them from being damaged by the cold.

Here are some common problems you might encounter with Swiss chard in the Midwest:

Leaf Miners

• What it looks like: Squiggly, white or yellow trails inside the leaves.
• What causes it: Small flies lay eggs on the leaves, and the larvae tunnel through the leaf tissue. They thrive in warm weather.
• How to fix/prevent it: Cover plants with row covers to prevent the flies from laying eggs. Remove and destroy affected leaves. Encourage beneficial insects like parasitic wasps.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer (it attracts them).

Cercospora Leaf Spot

• What it looks like: Small, circular spots on the leaves with tan or gray centers and reddish-brown borders. Spots may merge, causing leaves to yellow and die.
• What causes it: A fungal disease that thrives in warm, humid conditions.
• How to fix/prevent it: Provide good air circulation. Avoid overhead watering. Remove and destroy infected leaves. Apply a copper-based fungicide if necessary.

Slugs

• What it looks like: Irregular holes in leaves, especially low-growing plants. Silvery slime trails on leaves and soil. Damage worse at night and in wet weather.
• What causes it: Gastropods that feed at night in moist conditions. Hide under mulch, boards, and debris during the day.
• How to fix/prevent it: Beer traps (shallow dish of beer sunk into soil). Iron phosphate bait (pet-safe). Remove hiding spots. Water in morning so soil surface dries by evening. Copper tape around beds. Diatomaceous earth around plants.

Midwest Specific Challenges: The moderate-to-hot heat and moderate-to-humid humidity of our Midwest summers can create favorable conditions for fungal diseases like cercospora leaf spot. Be sure to provide good air circulation and avoid overhead watering to minimize these issues. Also, keep an eye out for slugs after heavy rains, which are common in our wet-summer climate.

Swiss chard benefits from companion planting. Lettuce makes a good companion because it doesn't compete for the same nutrients and can help shade the soil, keeping it cool. Onions and garlic deter pests, protecting your chard from unwanted visitors. Green beans fix nitrogen in the soil, which benefits chard's leafy growth, while cabbage family members like broccoli and kale have similar needs, making them good neighbors.

Avoid planting Swiss chard near corn or potatoes. Corn can shade the chard too much, hindering its growth. Potatoes can compete for the same nutrients in the soil, reducing the overall yield.