Echinacea in Zone 9A — Desert Southwest

Echinacea, also known as coneflower, is a fantastic addition to any Desert Southwest garden. Its vibrant blooms bring beauty, attract pollinators, and provide medicinal benefits, offering a rewarding experience for any gardener. Plus, they're surprisingly drought-tolerant, making them perfect for our arid climate.

While we face challenges like extreme heat and alkaline soil, Echinacea is well-suited to our long growing season. With careful timing and a bit of planning, you can enjoy these lovely blooms from spring all the way through fall. Our 298-day growing season gives you a wide window of opportunity.

Starting Echinacea indoors is an option, giving you a head start on the season, especially since we want to get them in the ground early. You can start seeds indoors from mid-December through early January, about eight weeks before transplanting. This timing takes advantage of our very-early spring character.

Use seed trays with a good seed-starting mix and provide warmth and light. A heat mat can help with germination. Don't forget to water from the bottom to avoid damping off.

Transplant your Echinacea seedlings outdoors from mid-February through early March. This allows the plants to establish themselves before the extreme heat of summer hits.

Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Plant them 18-24 inches apart in well-draining soil. Keep an eye out for late frosts, though they're usually mild by this point. Remember, Echinacea is a perennial, so choose its location wisely. It might be easier to buy established starts from a local nursery.

Direct sowing Echinacea is also possible in our climate, and it can be quite successful. Sow seeds from mid-February through late August, giving you a long window to work with.

Prepare the soil by loosening it and removing any rocks or debris. Keep in mind that Echinacea seeds need cold stratification, so if you are sowing in the spring, you'll want to look for pre-stratified seeds. Plant seeds 18-24 inches apart and keep the soil consistently moist until germination.

Echinacea is remarkably drought-tolerant once established, making it a great choice for water-wise Desert Southwest gardens. Avoid overwatering, as it can lead to root rot. Remember, we garden in an arid climate with monsoon moisture, so think like a desert plant.

During the spring and fall growing seasons, water deeply about once a week, providing roughly 1 inch of water per week. In the extreme summer heat, increase watering to twice a week if the soil is drying out quickly. Always use the "finger test" – stick your finger about 2 inches into the soil. If it feels dry, it's time to water.

Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases. Signs of underwatering include wilting leaves and stunted growth. Overwatering can cause yellowing leaves and root rot. A layer of mulch around the base of the plant helps retain moisture and regulate soil temperature.

Pruning Echinacea is simple and helps encourage continuous blooming. Deadhead spent flowers throughout the growing season to promote more blooms. Simply cut the stem just below the flower head.

In late winter, after the first frost, cut back the entire plant to the ground to prepare it for new growth in the spring. Alternatively, you can leave the seed heads on the plant for birds to enjoy over the winter, adding winter interest to your garden.

You can expect your first Echinacea harvest from mid-May through mid-December. This long harvest window takes advantage of our two growing seasons. The flowers are ready to harvest when they are fully open and the petals are vibrant.

To harvest, simply cut the stem just below the flower head. You can use the petals to make tea or other herbal remedies. Leaving some seed heads on the plant will attract goldfinches and other birds to your garden. As the first frost approaches in early December, harvest any remaining flowers and prepare the plants for their winter dormancy.

Even drought-tolerant Echinacea can have problems in the Desert Southwest. Here are some common issues and how to address them:

Aster Yellows

• What it looks like: Distorted, yellowed foliage, often with greenish flowers. The plant may also exhibit stunted growth.
• What causes it: A phytoplasma (bacteria-like organism) transmitted by leafhoppers. Common in our region.
• How to fix/prevent it: Unfortunately, there is no cure for aster yellows. Remove and destroy infected plants to prevent the spread of the disease. Control leafhopper populations with insecticidal soap.

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 behind a lacy appearance.
• What causes it: Japanese beetles are attracted to the foliage and flowers of Echinacea.
• 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: The extreme heat and intense sun can stress Echinacea, making it more susceptible to pests and diseases. Ensure adequate watering, especially during the summer months, and provide afternoon shade if necessary. Our alkaline soil can also be a challenge, so amend the soil with compost to improve drainage and nutrient availability.

Companion planting can benefit your Echinacea in the Desert Southwest.

Good companions include tomatoes and peppers, as they share similar watering needs and can benefit from the shade provided by the Echinacea. Herbs like rosemary and lavender are also great companions, as they attract pollinators and deter pests.

Avoid planting Echinacea near aggressive plants that may compete for water and nutrients. Also, avoid planting near plants that are susceptible to the same diseases, as this can increase the risk of infection.