Black-Eyed Susan in Zone 8B — Gulf Coast

Black-Eyed Susans are a ray of sunshine in your Gulf Coast garden, thriving even with our long, hot summers. Their bright yellow petals and dark centers bring cheer to any landscape, and they make fantastic cut flowers for your home. Plus, they're relatively low-maintenance, which is always a win.

Sure, our high humidity and disease pressure can be a challenge, but with the right timing and a little attention, Black-Eyed Susans will reward you with blooms from spring all the way into fall. Our long growing season, nearly 9 months, gives you plenty of time to enjoy them.

Starting Black-Eyed Susans indoors isn't essential here on the Gulf Coast, but it can give you a jump start, especially if you want blooms the very first year. This is especially handy because they are perennials.

If you want to start indoors, sow seeds from mid December through early January, about 8 weeks before our typical transplanting window. Use seed trays with a good seed-starting mix, provide warmth (a heat mat is helpful), and ensure they get plenty of light, either from a sunny window or a grow light. Bottom watering will help prevent damping off, a common problem with seedlings in our humid climate.

Keep in mind that our spring can come early, so be ready to adjust your plans if the weather warms up sooner than expected.

Transplanting Black-Eyed Susans outdoors is best done from mid February through mid March in our area. This gives them plenty of time to establish before the real heat hits.

Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade and increase the time and sunlight each day. Plant them 12-18 inches apart in a sunny spot with well-draining soil. Keep an eye on the weather forecast; those late-season cold snaps can still happen, so be prepared to cover them if necessary.

Direct sowing Black-Eyed Susan seeds is a perfectly viable option here in the Gulf Coast, and it's often the easiest. You can sow directly into the garden from mid February through early September.

Prepare the soil by loosening it and removing any weeds. Black-Eyed Susans aren't too picky about soil, but good drainage is essential, especially with our high rainfall. Sprinkle the seeds lightly over the soil and gently press them in. Keep the soil consistently moist until the seedlings emerge. Thin the seedlings to 12-18 inches apart once they are a few inches tall.

Black-Eyed Susans are wonderfully drought-tolerant once established, which is great for our sometimes unpredictable rainfall patterns here on the Gulf Coast. But that doesn't mean you can completely neglect them, especially when they're young.

During the first few weeks after planting, water regularly to help them establish a strong root system. After that, you can reduce watering frequency. A good rule of thumb is to water when the top 2 inches of soil feel dry to the touch – the "finger test." Typically, an inch of water per week is sufficient, but you might need to adjust based on rainfall.

In our humid climate, it's best to water at the base of the plants to avoid wetting the foliage, which can increase the risk of fungal diseases. Signs of underwatering include wilting leaves and stunted growth. Overwatering, on the other hand, can lead to root rot, so be sure your soil drains well. Mulching around the plants with pine straw or wood chips helps retain moisture and suppress weeds, both of which are beneficial in our climate.

Pruning Black-Eyed Susans is pretty straightforward. The main thing you'll want to do is deadhead the spent flowers to encourage more blooms.

Simply snip off the flower heads just below the bloom as they start to fade. You can do this throughout the growing season, from spring until fall. If you want to leave some seed heads for the birds or allow the plants to self-seed, that's perfectly fine too. In late winter, after the first frost around early December, cut back the entire plant to a few inches above the ground to make way for new growth in the spring.

You can expect to start harvesting Black-Eyed Susans for cut flowers from early May through early December here in the Gulf Coast. These beauties bloom for a long time, so you'll have plenty of opportunities to enjoy them.

The best time to harvest is when the flowers are fully open and the petals are brightly colored. Use sharp scissors or pruners to cut the stems at an angle, leaving several inches of stem on the plant. To encourage continued production, keep deadheading the spent flowers.

As the first frost approaches, you can still harvest any remaining blooms, but the plants will naturally start to slow down. Let the last flowers go to seed if you want them to self-sow for next year.

Black-Eyed Susans are generally easy to grow, but they can be susceptible to a few problems in our Gulf Coast climate, mainly due to our high humidity. The most common issues are powdery mildew, septoria leaf spot, and aphids.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die. Reduces plant vigor.
• 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 through spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays help. Milk spray (1 part milk to 9 parts water) is surprisingly effective. Plant resistant varieties.

Septoria Leaf Spot

• What it looks like: Small, circular spots on the leaves that start out brown and eventually turn gray with dark borders. Severe infections can cause leaves to drop.
• What causes it: A fungal disease that thrives in wet, humid conditions, especially when plants are overcrowded.
• How to fix/prevent it: Remove and destroy infected leaves. Improve air circulation around the plants. Water at the base of the plants to avoid wetting the foliage. Fungicides containing copper or chlorothalonil can be used in severe cases.

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).

Gulf Coast Specific Challenges: Our hot heat, very-high humidity, and wet-year-round rainfall create the perfect environment for fungal diseases like powdery mildew and septoria leaf spot to thrive on Black-Eyed Susans. Good air circulation and careful watering practices are essential to prevent these problems. Also, keep a close eye out for aphids, as they can multiply quickly in our warm climate.

Black-Eyed Susans make great companions for a variety of plants in your Gulf Coast garden.

They pair well with tomatoes because they attract beneficial insects that help pollinate the tomato plants and control pests. Squash also benefits from the presence of Black-Eyed Susans, as the flowers attract pollinators that ensure good fruit set. Herbs like rosemary, thyme, and oregano are also good companions, as their strong scents can help repel pests that might otherwise bother the Black-Eyed Susans.

Avoid planting Black-Eyed Susans near plants that are highly susceptible to powdery mildew, as this can increase the risk of the disease spreading.