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North America Native Plant

Western Giant Hyssop

Western Giant Hyssop: A Pacific Northwest Native Worth Discovering If you’re passionate about native gardening in the Pacific Northwest, you might want to get acquainted with western giant hyssop (Agastache occidentalis). This perennial herb is a true regional treasure, naturally occurring in just two states and offering gardeners a chance ...

Rare plant alert!

This plant is listed as rare and may be protected in certain regions. Its populations are limited, and removal from the wild could further endanger its survival. If you wish to enjoy this plant, consider sourcing from reputable nurseries that propagate responsibly or explore alternatives to help preserve natural populations.

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Western Giant Hyssop: A Pacific Northwest Native Worth Discovering

If you’re passionate about native gardening in the Pacific Northwest, you might want to get acquainted with western giant hyssop (Agastache occidentalis). This perennial herb is a true regional treasure, naturally occurring in just two states and offering gardeners a chance to support local ecosystems while adding something special to their landscapes.

What Makes Western Giant Hyssop Special

Western giant hyssop is a perennial forb – basically a non-woody flowering plant that comes back year after year. Unlike its woody shrub cousins, this plant stays herbaceous, with soft stems that die back in winter while the roots remain alive underground, ready to send up fresh growth when spring arrives.

As a member of the Agastache family, western giant hyssop likely shares some of the aromatic qualities that make other hyssops so beloved by gardeners and pollinators alike, though specific details about this particular species are somewhat limited in gardening literature.

Where Western Giant Hyssop Calls Home

This native beauty has a pretty exclusive address – you’ll only find it naturally growing in Oregon and Washington. Its limited native range makes it a true Pacific Northwest specialty, perfectly adapted to the unique conditions of this bioregion.

A Word About Rarity

Here’s something important to know: western giant hyssop carries a Global Conservation Status of S3?, which indicates some level of uncertainty about its conservation status. While we don’t have definitive data on how rare or common it is, this designation suggests it deserves our respect and careful consideration.

If you’re interested in growing western giant hyssop, make sure to source your plants or seeds from reputable native plant nurseries that can verify their stock comes from ethically collected, sustainably propagated sources. Never collect plants from wild populations.

Why Consider Western Giant Hyssop for Your Garden

Choosing native plants like western giant hyssop offers several compelling benefits:

  • Supports local wildlife and ecosystem relationships that evolved over thousands of years
  • Typically requires less water and maintenance once established, as it’s adapted to local conditions
  • Helps preserve regional plant diversity
  • Connects your garden to the natural heritage of the Pacific Northwest

Growing Western Giant Hyssop: What We Know

While specific growing information for Agastache occidentalis is limited, we can make some educated assumptions based on its native habitat in Oregon and Washington. As a Pacific Northwest native, it likely prefers:

  • Well-draining soils
  • Conditions that mimic its natural habitat
  • Minimal supplemental watering once established

Since detailed cultivation information is scarce, your best bet is to consult with local native plant societies, extension services, or specialty native plant nurseries in Oregon and Washington. These experts can provide region-specific advice about successfully growing this species.

The Bottom Line

Western giant hyssop represents an opportunity to grow something truly special – a plant that embodies the essence of Pacific Northwest flora. While information about this species is somewhat limited, that’s not uncommon for regionally endemic natives that haven’t received as much horticultural attention as more widespread species.

If you’re drawn to the idea of growing this Pacific Northwest native, approach it as an adventure in conservation gardening. Connect with local native plant groups, seek out knowledgeable growers, and remember that by choosing natives like western giant hyssop, you’re participating in the important work of preserving regional biodiversity right in your own backyard.

Just remember: always source responsibly, and when in doubt, consult the experts who know your local growing conditions best.

Western Giant Hyssop

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Lamiales

Family

Lamiaceae Martinov - Mint family

Genus

Agastache Clayton ex Gronov. - giant hyssop

Species

Agastache occidentalis (Piper) A. Heller - western giant hyssop

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA