Multiflora Rose
Beginning of floweringRosa multiflora
Rosaceae · broadleaf deciduous shrub · naturalized
Last updated
Multiflora rose (Rosa multiflora) is a broadleaf shrub in the Rosaceae family native to Japan and Korea, now widely naturalized in North America. It reaches 15 ft tall and produces white fragrant conical flower clusters with flowers approximately 2 cm across. It originally grows on slopes and scrub in eastern Asia.
Multiflora rose is hardy in zones 5a-8b and prefers full sun with moist soil (pH 4.5-8.5). It has high maintenance requirements. Twenty-seven diseases and 29 pests are documented. The species has significant weed and invasive potential and is classified as a noxious weed in multiple states.
Quick Facts
Primary Infection
Spring New Growth - Early Infection Window
Aecial Stage (Alternate Host)
Root Colonization Period
+ 8 more — see full disease and pest lists below
Phenological Calendar
As of May 13, 2026, Puget Sound stations range from 1906.2 to 2098.2 GDD₃₂. Multiflora Rose has passed beginning of flowering (2082 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 13, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,098 | Beginning of flowering | — | — |
| Kent / Auburn | 2,089 | Beginning of flowering | — | — |
| Seattle / UW | 2,063 | Pre-season | Beginning of flowering | 19 |
| Olympia / Tumwater | 2,025 | Pre-season | Beginning of flowering | 57 |
| Tacoma / Puyallup | 1,993 | Pre-season | Beginning of flowering | 89 |
| Bellingham / Whatcom | 1,972 | Pre-season | Beginning of flowering | 110 |
| Sequim / Rain Shadow | 1,906 | Pre-season | Beginning of flowering | 176 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ● Beginning of flowering BBCH 61 NOW | 2082 | — |
Source: OSU phenology catalog (OSU: weather.cfaes.osu.edu) About GDD₃₂ →
Season tracker for Kent / Auburn as of May 13, 2026. Predicted dates use 16-day weather forecast through May 29, 2026, then climate normals.