Black-Eyed Susan in Zone 6A — Mountain West

Black-Eyed Susans are worth growing in our Mountain gardens for their vibrant, cheerful blooms that bring a splash of sunshine to any landscape. They are fantastic cut flowers, and their long bloom period extends the color in your garden well into fall. Plus, they are incredibly low-maintenance, a real bonus for us high-altitude gardeners!

Our short growing season and alkaline soil can present challenges, but Black-Eyed Susans are surprisingly adaptable. With a little planning and proper timing within our 153-day window, you can enjoy these beauties year after year.

Starting Black-Eyed Susans indoors is an option, especially if you're itching to get a head start on the season. Sow seeds indoors from mid-February through mid-March, roughly eight weeks before you plan to transplant them.

Use seed trays with a good seed-starting mix, and keep them in a warm location with plenty of light – a sunny south-facing window or grow lights work well. Bottom watering helps prevent damping off, which can be a problem in our cool spring conditions. While you *can* start indoors, it's often easier to direct sow once the soil warms up, given our late springs.

Transplanting Black-Eyed Susans outdoors should happen in late April through late May. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Plant them 12-18 inches apart in a sunny spot with well-drained soil. Keep an eye on the weather forecast; late frosts are not uncommon in the Mountains, so be prepared to cover your seedlings if needed. As a perennial, buying starts might give you flowers the first year instead of waiting.

Direct sowing Black-Eyed Susan seeds is a straightforward option for Mountain gardeners. Sow seeds directly into the garden from early May through early July, once the soil has warmed up a bit.

Prepare the soil by loosening it and removing any weeds. Gently press the seeds into the soil, but don't bury them too deeply. Keep the soil consistently moist until the seedlings emerge. Thin seedlings to 12-18 inches apart. Direct sowing is simple, but you'll need patience since they may not flower until the second year.

Black-Eyed Susans are remarkably drought-tolerant once established, which is a huge advantage in our dry Mountain climate. During the first few weeks after planting, water regularly to help them get established.

After that, you can significantly reduce watering. A good rule of thumb is to check the soil about two inches deep; if it's dry, it's time to water. In our region, you'll likely only need to water deeply once a week, maybe twice during the hottest stretches of summer.

Water at the base of the plant to avoid wetting the foliage, which can minimize the risk of fungal diseases in our low-humidity environment. Signs of underwatering include wilting leaves; overwatering can lead to yellowing leaves. Mulching around the base of the plants with gravel or wood chips helps retain moisture and regulate soil temperature, especially with our intense sun.

To encourage a longer bloom period for your Black-Eyed Susans, deadhead spent flowers regularly throughout the growing season. Simply snip off the faded blooms just below the flower head.

Alternatively, you can leave some seed heads on the plants to provide food for birds and allow for self-seeding. In late winter or early spring, before new growth emerges, cut the plants back to the ground to tidy them up.

You can expect your Black-Eyed Susans to start blooming from mid-July through early October, adding a burst of color to your Mountain garden. These flowers make excellent cut flowers, so feel free to snip them as needed to brighten up your home.

Harvest the flowers when they are fully open and the petals are vibrant. Cut the stems at an angle, and place them in water immediately. To encourage continued production, keep deadheading spent flowers. As the first frost approaches in early October, you can collect any remaining blooms to enjoy indoors.

Black-Eyed Susans are generally easy to grow, but here are a few common problems you might encounter in our region:

Powdery Mildew

• What it looks like: A white or grayish powdery coating on the leaves and stems. Leaves may curl, yellow, and die.
• What causes it: Fungal disease favored by warm days, cool nights, and moderate humidity. Ironically, dry leaf surfaces promote it. This is a common issue due to our temperature swings.
• How to fix/prevent it: Improve air circulation by spacing plants adequately. Remove affected leaves promptly. Apply neem oil or potassium bicarbonate sprays. Milk spray (1 part milk to 9 parts water) can also be effective.

Septoria Leaf Spot

• What it looks like: Small, circular spots on leaves, often with dark brown or black borders. Spots may merge, causing leaves to yellow, brown, and drop.
• What causes it: Fungal disease that thrives in humid conditions and spreads through splashing water. While our humidity is low, overhead watering can create localized humid microclimates.
• How to fix/prevent it: Remove and destroy infected leaves. Avoid overhead watering. Improve air circulation. Apply copper-based fungicides if needed.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and the undersides of leaves. Sticky honeydew residue and curled or distorted new growth.
• What causes it: Sap-sucking insects that reproduce rapidly, especially in warm weather. They are often “farmed” by ants.
• How to fix/prevent it: Knock aphids off plants with a strong stream of water. Encourage natural predators like ladybugs. Use insecticidal soap or neem oil for heavy infestations. Avoid over-fertilizing with nitrogen, which attracts aphids.

Mountain West Specific Challenges: Our intense UV radiation can sometimes stress plants, making them more susceptible to problems. Ensure Black-Eyed Susans are adequately watered, especially during prolonged dry spells, to help them withstand these challenges. Hail can also damage foliage, so consider providing temporary protection during severe storms.

Black-Eyed Susans benefit from companion planting, and there are several great choices for our Mountain gardens. Tomatoes make good companions because they share similar sun and water requirements, and Black-Eyed Susans can attract beneficial insects that prey on tomato pests. Squash also pairs well, as the large leaves can help shade the soil, keeping it cooler and more moist. Herbs like rosemary, thyme, and oregano are excellent companions as they attract pollinators and can help deter pests with their strong scents. Avoid planting near anything prone to root competition, as Black-Eyed Susans prefer to have space to spread their roots.