Agastache

Agastache is a genus of flowering plants in the mint family, Lamiaceae. Commonly known as giant hyssop or hummingbird mint, these herbaceous perennials are prized for their long-lasting flower spikes and aromatic foliage. They are a favorite among gardeners for their ability to attract a wide variety of pollinators.

Key Characteristics

• Appearance: Agastache plants have an upright, clump-forming growth habit with stiff, angular stems. The foliage is typically green and has a minty or anise-like scent when crushed. Tall, showy spikes of tubular, two-lipped flowers rise above the leaves, creating a vertical accent in the garden.
• Flowers: The flowers come in a wide range of colors, including various shades of blue, purple, pink, orange, red, and white. They bloom profusely from mid-summer through autumn, providing a continuous source of nectar for pollinators.
• Pollinator Magnet: Agastache is exceptionally attractive to bees, butterflies, hummingbirds, and other beneficial insects, making it a staple in pollinator and wildlife gardens.

Care and Growing Conditions

• Sunlight: Agastache thrives in full sun. They need at least 6-8 hours of direct sunlight per day to flower well and maintain a sturdy, non-leggy shape. In hot climates, some afternoon shade can be beneficial, but too much shade will result in fewer flowers and weaker stems.
• Soil: The most critical requirement for agastache is well-draining soil. They are highly susceptible to root rot in heavy, wet soil. They tolerate a range of soil types, from sandy to loamy, but will do best in moderately fertile ground.
• Watering: Once established, agastache is very drought-tolerant, a trait inherited from its North American origins. Water deeply during the first growing season to help establish a strong root system. After that, they rarely need supplemental watering unless there is a prolonged dry spell.
• Pruning: Deadheading (removing spent flower spikes) is recommended to encourage a longer blooming period. In late autumn, you can either leave the old flower stems for winter interest and to provide food for birds, or you can cut them back. A harder pruning in early spring will promote new, bushy growth.
• Winter Hardiness: Hardiness varies by species and cultivar. Many are hardy in USDA zones 6-10, but some newer hybrids have been bred for greater cold tolerance. In colder regions, a layer of mulch in the autumn can help protect the plant’s crown.

Common Varieties

• Agastache foeniculum (Anise Hyssop): Known for its fragrant, anise-scented foliage and lavender-blue flowers.
• Agastache ‘Blue Fortune’: A popular and reliable hybrid with spikes of soft blue-purple flowers.
• Agastache rupestris (Sunset Hyssop): Features striking orange-pink flowers and is very popular for its ornamental appeal.
• ‘Kudos’ and ‘Mango Tango’ series: These are modern cultivars bred for a more compact habit and a wider range of colors, including yellow and orange tones.