Black-Eyed Susan in Zone 3B — Midwest

Black-Eyed Susans are a ray of sunshine in any Midwest garden, and they're surprisingly easy to grow. Their cheerful blooms brighten up borders, attract pollinators, and make fantastic cut flowers. Plus, they're perennials, so you'll enjoy them year after year.

Our Midwest weather can be unpredictable, with late frosts and summer heat spells. But with a little planning and attention to timing, you can absolutely succeed with Black-Eyed Susans. Our 118-day growing season is plenty of time to get them established and blooming.

Starting Black-Eyed Susan seeds indoors gives you a head start, but it's honestly not essential. Direct sowing works just fine. However, if you're impatient or want blooms the very first year, starting indoors is the way to go.

You'll want to start your seeds mid-March through early April, about eight weeks before you plan to transplant them outdoors. Use seed trays with a good seed-starting mix, keep them warm (around 70°F), and provide plenty of light – a simple shop light works great. Don't forget to water from the bottom to avoid damping off. With our moderate-to-late spring, this timing gives your seedlings a good chance to get strong before going outside.

Transplant your Black-Eyed Susans outdoors mid-May through early June, after the risk of frost has passed. Before you plant them in the ground, you'll need to harden them off. Expose them to gradually increasing amounts of outdoor time over about a week.

When you're ready to plant, space them 12-18 inches apart in a sunny spot with well-drained soil. Keep an eye on the weather forecast – a late frost can still happen, so be prepared to cover your seedlings if necessary. Black-Eyed Susans are perennial. If you want blooms the first year, it's best to buy established plants.

Direct sowing Black-Eyed Susan seeds is a straightforward option, and it's how they often spread on their own. The key is to wait until the soil has warmed up properly.

Sow the seeds mid-May through mid-June, after the last frost. Prepare the soil by loosening it and removing any weeds. Scatter the seeds thinly over the surface, and gently press them into the soil. Keep the soil consistently moist until the seedlings emerge. Thin them to 12-18 inches apart as they grow.

Black-Eyed Susans are known for being drought-tolerant once they're established, making them a great choice for busy Midwest gardeners. However, they do need consistent watering while they're getting started.

During the first few weeks after transplanting or direct sowing, water regularly to keep the soil consistently moist. After that, you can ease up. A good rule of thumb is to water when the top two inches of soil feel dry to the touch – the "finger test." Typically, an inch of water per week, whether from rain or irrigation, is plenty. With our wet-summer rainfall, you might not need to water much at all after they are established.

Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our moderate-to-humid climate. Overwatering can lead to root rot, so watch out for yellowing leaves and stunted growth. Underwatering will cause the leaves to wilt and turn brown. A layer of mulch around the base of the plants helps retain moisture and suppress weeds.

Pruning Black-Eyed Susans is simple and helps keep them blooming longer. The main thing you'll want to do is deadhead the spent flowers.

Deadheading encourages the plant to produce more blooms instead of putting energy into seed production. Simply snip off the faded flowers just below the flower head. You can do this throughout the growing season, from midsummer until the first frost. If you want to attract birds or encourage self-seeding, you can leave some of the seed heads on the plant at the end of the season. In late winter or early spring, before new growth emerges, cut back the entire plant to a few inches above the ground.

Black-Eyed Susans provide a long season of cheerful blooms, making them a rewarding addition to any Midwest garden. You can expect your first harvest of flowers from early August through late September, about 75 days after planting.

The best time to harvest Black-Eyed Susans for cut flowers is when the blooms are fully open and the petals are still fresh. Cut the stems at an angle, leaving as much foliage on the plant as possible. To encourage continuous production, keep deadheading the spent flowers. As the first frost approaches around mid-September, you can cut back the plants to encourage new growth next spring, or leave the seed heads for the birds.

Even though Black-Eyed Susans are relatively easy to grow, they can still be susceptible to a few common problems in the Midwest. Here are three to watch out for:

Powdery Mildew

• What it looks like: A white or grayish powdery coating on the leaves, stems, and sometimes buds. Leaves may curl, yellow, and die.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it (unlike most fungi).
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning. Remove affected leaves promptly. Neem oil or potassium bicarbonate sprays can help. Milk spray (1 part milk to 9 parts water) is surprisingly effective. Plant resistant varieties if available.

Septoria Leaf Spot

• What it looks like: Small, circular spots on the leaves that are initially dark brown or black, often with a yellow halo. The spots may enlarge and merge, eventually causing the leaves to turn yellow and drop off.
• What causes it: A fungal disease that spreads through splashing water and infected plant debris. Wet conditions and poor air circulation promote its development.
• How to fix/prevent it: Remove and destroy infected leaves. Improve air circulation by spacing plants properly and pruning. Water at the base of the plants to avoid wetting the foliage. Apply a copper-based fungicide if necessary. Clean up plant debris in the fall to reduce the spread of the disease.

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: A strong water spray can knock them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap is effective for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer, which attracts them.

Midwest Specific Challenges: Our moderate-to-hot summers and moderate-to-humid conditions can create a favorable environment for fungal diseases like powdery mildew and septoria leaf spot. Be sure to provide good air circulation and avoid overhead watering to minimize these problems. The wet-summer rainfall can also contribute to the spread of fungal diseases, so keep a close eye on your plants during periods of heavy rain.

Black-Eyed Susans make great companions for a variety of plants in the Midwest garden. They attract pollinators, which can benefit your tomatoes, squash, and herbs.

Tomatoes and squash benefit from the increased pollination that Black-Eyed Susans bring. Herbs like basil and oregano can help deter pests that might otherwise bother your Black-Eyed Susans. Avoid planting them near anything that will shade them out, as they need full sun to thrive.