San Francisco Bluegrass: A Rare Pacific Coast Native Worth Protecting
Meet San Francisco bluegrass (Poa unilateralis), a delicate perennial grass that’s as rare as it is beautiful. This Pacific Coast native might not be the showiest plant in your garden, but it’s got a quiet charm that makes it perfect for gardeners who appreciate subtle beauty and want to support local ecosystems.
What Makes San Francisco Bluegrass Special?
This fine-textured grass belongs to the same family as your lawn grass, but don’t expect it to create a putting-green perfect turf. Instead, San Francisco bluegrass offers an airy, naturalistic appearance with its characteristic one-sided flower clusters (that’s what unilateralis means – one-sided!). It’s a true native of the American West, specifically calling California, Oregon, and Washington home.
As a perennial graminoid, this grass returns year after year, slowly spreading to form loose colonies that sway gracefully in coastal breezes.
Where Does It Grow Naturally?
San Francisco bluegrass has a limited range along the Pacific Coast, growing naturally in California, Oregon, and Washington. You’ll find it thriving in coastal areas and inland valleys where Mediterranean climates prevail.
A Word of Caution: This Grass is Rare
Important: San Francisco bluegrass has a Global Conservation Status of S3, meaning it’s considered vulnerable throughout its range. With typically only 21 to 100 occurrences and between 3,000 to 10,000 individuals worldwide, this isn’t a plant to take lightly. If you’re interested in growing it, please only source it from reputable native plant nurseries that propagate it responsibly – never collect from wild populations.
Growing Conditions and Care
The good news? Once you’ve found responsibly sourced San Francisco bluegrass, it’s relatively easy to grow in the right conditions:
- Sunlight: Partial shade to full sun
- Soil: Well-drained soils; avoid soggy conditions
- Water: Drought tolerant once established, though appreciates occasional summer water
- Climate: Best suited for USDA hardiness zones 8-10
According to wetland status classifications, this grass is considered Facultative Upland, meaning it usually grows in non-wetland areas but can occasionally tolerate wetter conditions.
Perfect for Naturalistic Gardens
San Francisco bluegrass isn’t the star of the show – it’s more like the perfect supporting actor. Use it as:
- Groundcover in native plant gardens
- Erosion control on gentle slopes
- Texture contrast with broader-leaved native plants
- Part of restoration projects in appropriate habitats
This grass works beautifully in naturalistic landscapes where you want to recreate the feeling of wild coastal grasslands without the maintenance headaches of a traditional lawn.
Wildlife and Ecosystem Benefits
As a native grass, San Francisco bluegrass provides important habitat structure for small wildlife and helps maintain the ecological relationships that evolved over thousands of years in Pacific Coast ecosystems. While it’s wind-pollinated (so it won’t attract butterflies like wildflowers do), it plays a crucial role in the complex web of native plant communities.
Should You Plant It?
If you’re gardening within its native range and can source it responsibly, San Francisco bluegrass makes a wonderful addition to native plant gardens. Its rarity makes it even more valuable – by growing it in appropriate garden settings, you’re helping ensure this beautiful grass doesn’t disappear from our landscapes entirely.
Just remember: with great rarity comes great responsibility. Only purchase from nurseries that grow it from legally and ethically obtained seed, and consider it a privilege to help conserve this vulnerable species in your own backyard.
