Japanese Kerria Japanese Rose
'Full bloom'Kerria japonica
Rosaceae · broadleaf deciduous shrub · introduced
Last updated
Plant Profile
Size & Form
Height
4–8 ft
Spread
6 ft
Growth Rate
Medium
Site Requirements
Light
Part Shade
Soil Drainage
Moist
Soil pH
4.5-8.5
Water
Moderate
Drought Tolerance
Moderate to high
Hardiness
Zones 4a–8b
Ornamental Interest
Bloom Time
april to may
Fall Color
Yellow
Origin
central and western China, several cultivars available
Watch for this season
Powdery MildewHigh
Active Conidial Spread
RustHigh
Uredinial Stage (Summer)
Black SpotModerate
Active Spread & Lesion Expansion
Downy MildewModerate
Late Spring - Summer Transition
+ 3 more — see full disease and pest lists below
Diseases: Regionally Documented (10)
Raspberry bushy dwarf virus and related viruses Virus Multiple genera (Melampsoridium, Thekopsora, Naohidemyces... Rust Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew Multiple obligate oomycetes (Peronosporaceae); species ar... Downy Mildew Rhizobium radiobacter (formerly Agrobacterium tumefaciens) Crown Gall Coniothyrium wernsdorffiae and Paraconiothyrium fuckelii Common canker Kalmusia coniothorium Brand canker Botrytis Bud and Twig Blight [NOTE: Diplocarpon rosae causes black spot on roses (Rosa... Black Spot Chlaropsis thielavioides Black Mold
Pests: Regionally Documented (13)
Diabrotica undecimpunctata Western spotted cucumber beetle Chloridea virescens Tobacco budworm Thysanoptera Thrips Tetranychidae Spider mite Endelomyia aethiops Roseslug Dasineura rhodophaga Rose midge Edwardsiana rosae Rose leafhopper Diplolepis rosae Rose galls Macrosiphum rosae Rose aphid Otiorhynchus spp. Root weevil Schizura concinna Redhumped caterpillar Tortricidae Leafroller Megachile spp. Leafcutting bee
Phenological Calendar
As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Japanese Kerria Japanese Rose has passed 'full bloom' (1229 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,673 | 'Full bloom' | — | — |
| Kent / Auburn | 2,665 | 'Full bloom' | — | — |
| Seattle / UW | 2,610 | 'Full bloom' | — | — |
| Olympia / Tumwater | 2,570 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 2,535 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 2,533 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 2,436 | 'Full bloom' | — | — |
View full calendar (2 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 1008 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1229 | '' |
Range: 768–918 GDD₃₂
(6yr)
Source: 'Master catalog (OSU), converted GDD50->GDD32 via Kent bloom-date mapping' About GDD₃₂ →
Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.
Cultivars (5)
'Albiflora'
Common name: White Japanese Kerria, Albiflora Japanese Kerria; Mature height: 4–5 ft
Hardy to USDA Zone 4
'Golden Guinea'
Common name: Golden Guinea Japanese Kerria; Mature height: 4–5 ft
Hardy to USDA Zone 4
'Kin Kan'
Common name: Kin Kan Japanese Kerria
Hardy to USDA Zone 4
'Picta'
Common name: Variegated Japanese Kerria, Picta Japanese Kerria; Mature height: 3–4 ft
Hardy to USDA Zone 4
'Pleniflora'
Common name: Double Japanese Kerria; Mature height: 4–8 ft
Hardy to USDA Zone 4
Data Maturity Structured Multiple sources. Expert review underway.