Agastache: A Comprehensive Guide to Growing and Care
Agastache Overview
Agastache, commonly known as giant hyssop or hummingbird mint, is a genus of herbaceous perennials that are native to North America, South America, and Asia. These plants are prized for their beautiful flower spikes, which attract a variety of pollinators, including bees, butterflies, and hummingbirds. Agastache is also known for its drought tolerance and ability to thrive in a wide range of soil conditions.
Agastache Care
Caring for agastache is relatively easy. Here are the key requirements:
- Sunlight: Agastache prefers full sun but can tolerate partial shade.
- Soil: The ideal soil for agastache is well-drained and has a pH between 6.0 and 7.0.
- Water: Agastache is drought tolerant and only needs occasional watering during dry periods. Avoid overwatering, as this can lead to root rot.
- Fertilizer: Agastache does not require heavy fertilization. A light application of compost in the spring or fall is sufficient.
Types of Agastache
There are over 22 different species of agastache, each with its own unique characteristics. Some of the most popular varieties include:
- Agastache cana (hummingbird mint): This variety is known for its abundant soft rose pink flowers and long blooming period.
- Agastache foeniculum (anise hyssop): This variety has a licorice-like scent and is attractive to bees.
- Agastache scrophulariifolia (purple giant hyssop): This variety grows up to 6 feet tall and has striking pale purple or pink blooms.
- Agastache rupestris (licorice mint hyssop): This variety has soft orange flowers and a combination of licorice and mint fragrance.
- Agastache ‘Blue Fortune’: This hybrid has soft periwinkle blue flowers.
Pruning Agastache
Pruning agastache is not essential, but it can help to keep the plants tidy and encourage more blooming. Here are some pruning tips:
- Pinch new growth in the spring to promote bushier plants.
- Deadhead spent flowers to prevent self-seeding and encourage more blooms.
- Cut back plants by one-third in the spring to encourage new growth.
Propagating Agastache
Agastache can be propagated by division or from cuttings. To propagate from cuttings:
- Take 6- to 8-inch cuttings of green stem in late summer or fall.
- Remove the lower leaves and scrape the exposed stem.
- Dip the scraped portion in rooting hormone and place the cuttings in a pot with well-draining soil.
- Water gently and cover with a plastic bag.
- Check for root growth in 2 to 3 weeks.
Growing Agastache from Seed
Agastache seeds require cold stratification to germinate. The best method is to direct sow them in the garden in the fall, so they are exposed to the winter cold temperatures.
Press seeds gently into the soil, no deeper than ¼ inch deep. Moisten the seeds every few days in the fall. If your winters are snowy, this will give them enough moisture to germinate in spring.
Growing Agastache in Pots
Agastache can be grown in containers as long as you provide enough room for its large root system. Choose a container with large drainage holes and a size that is at least two to three inches larger in diameter than the nursery pot. Use well-draining potting soil.
Overwintering Agastache
Perennial agastache varieties that are hardy in your climate do not need protection during the winter. The plant goes into dormancy in the fall, but leave the dead brown stems on the plant until spring.
Common Pests & Diseases
Agastache is not susceptible to serious pest or disease problems. However, root rot can occur in poorly drained soil. Other possible diseases include powdery mildew and leaf spot.
Agastache Bloom
Agastache is a long-lasting bloomer that typically blooms in midsummer to early fall. The flower spikes are tall and have a pungent, spicy fragrance. The scent varies depending on the species.
FAQ
- Is hummingbird mint invasive? No, but it can self-seed freely.
- Can you grow agastache from seed? Yes, but the seeds require cold stratification and light to germinate.
- How long does it take to grow agastache from seed? 14 to 21 days after stratification.
- How to prevent agastache from becoming invasive? Remove spent flower heads before the seeds can disperse.
- Which varieties of agastache attract the most hummingbirds? Agastache cana (hummingbird mint) and Agastache foeniculum (anise hyssop) are particularly attractive to hummingbirds.