Perennial Ryegrass
Lolium perenne · forage turf · frost-hardy
Nearly all U.S. perennial ryegrass seed comes from Oregon, which is why a 1997 Karnal bunt finding tied to Oregon ryegrass seed lots became an industry emergency: the state's grass seed economy and the wheat quarantine system collided. Ryegrass remains the quickest-establishing cool-season turf species and a major forage component.
Planting perennial ryegrass
Windows are computed per location from median frost dates. Pick a place on the Grow pages for exact dates; the rules by climate band:
| Zone band | Method | Timing |
|---|---|---|
| cool | direct sow | 21-60 days before first frost, Cool-season turf establishes best seeded in late summer to early fall. |
| temperate | direct sow | 14-21 days before last frost, Spring seeding is the fallback window. |
Who breeds & sells perennial ryegrass
Related crops: Wheat
Sources & References
Evidence: 1 source, all commercial catalogs. No independent reference documents this variety yet.
- Karnal Bunt on Oregon Ryegrass Seed (urgent memorandum) · ASTA Lawn Seed Division (1997), AMSeed Archive · archived original