Echinacea in Zone 9B — Desert Southwest

Echinacea, also known as coneflower, is a fantastic addition to any Desert Southwest garden. The vibrant blooms add beauty to your landscape, and the plant's medicinal properties are a bonus. Plus, you'll enjoy watching the goldfinches feast on the seed heads.

While our extreme heat and alkaline soil present challenges, Echinacea thrives with proper timing and care. With our long 313-day growing season, you can enjoy these beauties for months, especially if you take advantage of both of our growing seasons.

Starting Echinacea indoors in the Desert Southwest is possible, but not always necessary. If you want a head start, especially with specific varieties, begin in early to late December, about 8 weeks before transplanting.

Use seed trays with a well-draining seed-starting mix. Keep them consistently moist using bottom watering to avoid disturbing the tiny seeds. Place the trays in a warm location with plenty of light, either from a grow light or a bright, sunny window. Remember, our spring comes very early, so starting indoors helps you get ahead.

Transplant your Echinacea seedlings outdoors in early to late February, once the danger of frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Choose a sunny spot with well-draining soil, spacing plants 18-24 inches apart. While February is generally mild, keep an eye out for unexpected cold snaps that could damage young plants. Echinacea are perennials, so consider buying starts from a local nursery for easier results, as the seeds need cold stratification.

Direct sowing Echinacea seeds is a viable option in the Desert Southwest, especially if you're looking for a low-maintenance approach. Sow seeds directly into the garden from early February through early September.

Prepare the soil by loosening it and removing any rocks or debris. Echinacea prefers well-draining soil, so amend with compost if needed. Sow seeds 18-24 inches apart. Keep the soil consistently moist until germination, but avoid overwatering. Direct sowing is easier, but you might not get blooms until the second year.

Echinacea is surprisingly drought-tolerant once established, making it an excellent choice for desert gardening. However, proper watering is crucial, especially during the first year.

During the hottest months (June through August), water deeply about once every 1-2 weeks, providing about 1 inch of water each time. Use the finger test: stick your finger about 2 inches into the soil. If it feels dry, it's time to water. During the monsoon season (July-September), let the rainfall be your guide, but supplement if needed. In the cooler months (October through May), reduce watering to once every 2-3 weeks.

Water at the base of the plant to avoid wetting the foliage, as our arid climate doesn't completely eliminate the risk of fungal diseases. Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to root rot, indicated by yellowing leaves and a mushy stem. A layer of gravel mulch helps retain moisture and regulate soil temperature.

Pruning Echinacea is simple and helps encourage more blooms. Throughout the growing season, deadhead spent flowers by cutting the stem just below the flower head. This encourages the plant to produce more flowers instead of focusing on seed production.

In late winter (January-February), before new growth begins, cut back the entire plant to a few inches above the ground. This clears away any dead foliage and prepares the plant for a new season of growth. Alternatively, leave some seed heads standing through the winter to provide food for birds and add winter interest to your garden.

You can expect your first Echinacea harvest from early May through late December, about 90 days after planting. The flowers are ready to harvest when the petals are fully open and the central cone is prominent.

To harvest, simply cut the stem just below the flower head. You can use the petals fresh or dry them for tea. Leave some seed heads on the plant to attract goldfinches and allow the plant to self-seed. As the first frost approaches in mid- December, you can harvest any remaining flowers or leave them for winter interest. Echinacea provides a continuous harvest throughout our long growing season.

Here are some potential problems you might encounter growing Echinacea in the Desert Southwest:

Aster Yellows

• What it looks like: Distorted, greenish flowers, often with tufts of growth in the center. The plant may also be stunted and yellowed.
• What causes it: A disease spread by leafhoppers. These insects thrive in warm weather, and our long, hot summers provide ample opportunity for them to transmit the disease.
• How to fix/prevent it: Unfortunately, there is no cure for aster yellows. Remove and destroy infected plants immediately to prevent the spread of the disease. Control leafhopper populations with insecticidal soap or neem oil.

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.

Japanese Beetles

• What it looks like: Metallic green beetles that skeletonize leaves, leaving only the veins.
• What causes it: Japanese beetles are attracted to plants in full sun.
• How to fix/prevent it: Handpick beetles off plants and drop them into a bucket of soapy water. Use row covers to protect plants. Neem oil can also deter beetles.

Desert Southwest Specific Challenges: Our extreme heat and low humidity can stress Echinacea, making them more susceptible to pests and diseases. While they are drought-tolerant, consistent watering during the hottest months is crucial. Alkaline soil can also be a challenge. Amend the soil with compost to improve drainage and nutrient availability.

Echinacea benefits from companion planting in the Desert Southwest. Tomatoes and peppers make good companions because they share similar sun and water requirements. Planting them together can also help attract beneficial insects that pollinate both Echinacea and your vegetable crops.

Herbs like rosemary and lavender are also excellent companions. These herbs attract pollinators and their strong scent can deter some pests. Avoid planting Echinacea near plants that require a lot of water, as this can lead to overwatering and root rot.