Purple Giant Hyssop: A Towering Native Beauty for Your Garden
If you’re looking for a native perennial that combines impressive height, gorgeous purple blooms, and serious pollinator appeal, let me introduce you to purple giant hyssop (Agastache scrophulariifolia). This underappreciated native gem deserves a spot in more gardens across North America.
What is Purple Giant Hyssop?
Purple giant hyssop is a perennial herb native to both Canada and the lower 48 United States. True to its name, this plant is indeed a giant among the Agastache family, often reaching impressive heights that make it a standout in any garden setting. As a forb (a non-woody flowering plant), it dies back to the ground each winter but reliably returns each spring.
Where Does it Grow Naturally?
This native beauty has an extensive natural range across eastern and central North America. You’ll find it growing wild in Ontario and 29 U.S. states, including Connecticut, Delaware, District of Columbia, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, South Dakota, Tennessee, Vermont, Virginia, West Virginia, and Wisconsin.
A Note About Rarity
While purple giant hyssop has a wide distribution, it’s worth noting that this species has become quite rare in some areas. In New Jersey, for example, it holds a rarity status of S2 and is listed as a Highlands species of concern. If you’re planning to add this beauty to your garden, please source it responsibly from reputable native plant nurseries rather than collecting from wild populations.
Why Grow Purple Giant Hyssop?
There are several compelling reasons to consider this native for your landscape:
- Pollinator magnet: The purple flower spikes are irresistible to bees, butterflies, and even hummingbirds
- Long blooming period: Provides nectar and color from mid to late summer when many other plants are winding down
- Low maintenance: Once established, it’s quite drought tolerant and requires minimal care
- Architectural presence: Its tall stature adds vertical interest and structure to plantings
- Native credentials: Supporting local ecosystems while creating beautiful gardens
Garden Design Ideas
Purple giant hyssop shines in several garden settings:
- Back of the border: Use its height to create a stunning backdrop for shorter perennials
- Prairie gardens: Perfect for naturalistic plantings alongside other native grasses and wildflowers
- Pollinator gardens: An essential component of any bee and butterfly garden
- Cottage gardens: Adds that informal, old-fashioned charm with its tall, spiky blooms
Growing Conditions and Care
The good news is that purple giant hyssop is relatively easy to please:
- Sunlight: Prefers full sun but tolerates partial shade
- Soil: Thrives in well-drained soils; avoid areas that stay consistently wet
- Hardiness: Hardy in USDA zones 4-8, making it suitable for most temperate regions
- Water: Drought tolerant once established, though regular watering in the first year helps establishment
Planting and Care Tips
Getting started with purple giant hyssop is straightforward:
- Plant in spring after the last frost date
- Space plants 2-3 feet apart to allow for their mature spread
- Water regularly the first year to establish a strong root system
- Deadhead spent flowers to encourage continued blooming, or leave them for wildlife to enjoy the seeds
- Cut back to ground level in late fall or early spring
- Division is rarely necessary, but can be done in spring if desired
Wildlife Benefits
Beyond its stunning appearance, purple giant hyssop provides valuable ecosystem services. The flowers attract a variety of pollinators throughout their long blooming season, while the seeds provide food for birds in fall and winter. The aromatic foliage may also help deter some garden pests naturally.
The Bottom Line
Purple giant hyssop deserves serious consideration for any gardener interested in native plants, pollinator support, or simply beautiful, low-maintenance perennials. While it may be lesser-known compared to some of its Agastache cousins, this native giant offers impressive height, gorgeous blooms, and serious ecological value. Just remember to source your plants responsibly, especially if you’re in an area where it’s become rare. Your garden—and local pollinators—will thank you for including this magnificent native in your landscape.
