Black-Eyed Susan in Zone 3B — Great Plains

Black-Eyed Susans are a burst of sunshine in our Great Plains gardens. They're easy to grow, drought-tolerant, and the bright yellow flowers are just what we need to lift our spirits after a long winter. Plus, they make fantastic cut flowers to bring a bit of the prairie indoors.

We all know gardening in the Plains isn't without its challenges – extreme temperature swings, the occasional hail storm, and our relatively short 118-day growing season. But with a little planning and attention to timing, even a beginner can successfully grow Black-Eyed Susans here.

Starting Black-Eyed Susans indoors isn't strictly necessary, but it can give you a head start, especially if you're impatient for blooms the first year. If you want to go this route, aim to sow seeds indoors from mid-March through early April, about 8 weeks before you plan to transplant.

Use seed trays with a good seed-starting mix, keep them consistently warm, and provide plenty of light – a grow light works wonders. Water from the bottom to avoid damping off; just set the tray in a shallow pan of water until the soil surface is moist. Remember, spring here is variable, so keep an eye on the weather forecast before you get too eager.

Once the danger of frost has passed, usually from mid-May through early June, it's time to transplant your Black-Eyed Susans outdoors. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind.

Plant them 12-18 inches apart in a sunny spot with well-drained soil. Even though we often have warm days by transplant time, a late frost can still sneak in, so be prepared to cover your seedlings if necessary. Given that they are perennials, buying starts from a local nursery will ensure flowers the first year.

Direct sowing Black-Eyed Susan seeds is a perfectly viable option, especially if you're not in a rush for blooms. Wait until the soil has warmed up, typically from mid-May through mid-June, to sow your seeds directly into the garden.

Prepare the soil by loosening it and removing any weeds. Sow seeds about 1/4 inch deep and keep the soil consistently moist until they germinate. Thin seedlings to 12-18 inches apart. Direct sowing is lower maintenance, but you might not see flowers until the second year.

Black-Eyed Susans are surprisingly drought-tolerant, which is a huge plus in the Great Plains, where rainfall can be unpredictable. Once established, they need very little supplemental watering.

During the first few weeks after planting, water regularly to help them get established. After that, let the soil dry out between waterings. Stick your finger about 2 inches deep into the soil; if it feels dry, it's time to water. Generally, an inch of water per week is plenty, unless we're in a prolonged dry spell. Water at the base of the plant to avoid wetting the foliage, especially since we have low-to-moderate humidity.

Yellowing leaves can indicate overwatering, while drooping leaves signal underwatering. A layer of mulch around the base of the plants will help retain moisture and suppress weeds, which is beneficial in our hot summers.

To encourage a longer bloom period, deadhead Black-Eyed Susans regularly throughout the summer. Simply snip off the faded flowers just below the flower head.

If you prefer, you can leave some of the seed heads on the plants in the fall. The birds will appreciate the seeds, and you might get some self-seeding, which can fill in your garden over time. In late winter or early spring, cut the plants back to a few inches above the ground to encourage new growth.

Black-Eyed Susans typically start blooming from early August through late September, about 75 days after sowing. The flowers are ready to harvest when they are fully open and the petals are bright yellow.

Cut the stems at an angle, leaving a few inches of stem on the plant. Removing spent blooms will encourage more flowers. As the first frost approaches in mid-September, you can cut all the remaining flowers to bring indoors. Black-Eyed Susans self-seed readily, so you'll likely have new plants popping up next year.

Here are a few common problems to watch out for with Black-Eyed Susans in the Great Plains:

Powdery Mildew

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

Septoria Leaf Spot

• What it looks like: Small, circular spots on leaves, usually dark brown or black with a lighter center. Spots may merge, causing leaves to turn yellow and drop off.
• What causes it: A fungal disease that spreads quickly in wet conditions. Splashing water spreads the spores from infected leaves to healthy ones.
• How to fix/prevent it: Remove and destroy infected leaves promptly. Improve air circulation around plants. Water at the base of the plant to avoid wetting the foliage. Apply a fungicide containing copper or chlorothalonil if necessary.

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: Rapidly 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 can be used for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer, which attracts them.

Great Plains Specific Challenges: Our hot summers and variable rainfall can stress Black-Eyed Susans, making them more susceptible to problems. Wind protection is essential, as strong winds can damage the foliage and stems. While they are drought-tolerant, prolonged dry spells can weaken them, so be sure to provide supplemental water when needed.

Black-Eyed Susans make excellent companions for several plants in the Great Plains garden. Tomatoes benefit from their presence, as the bright flowers attract pollinators, leading to better fruit set. Squash also appreciates the extra pollinators.

Herbs like rosemary, thyme, and lavender are good companions, as their strong scents can help deter pests that might otherwise bother the Black-Eyed Susans. Avoid planting them near anything that requires constant watering, as they prefer drier conditions.