Radiant Crabapple
Full bloomMalus 'Radiant'
Rosaceae · broadleaf deciduous tree · introduced
Last updated
Quick Facts
Bloom Infection Window
Spring Emergence / Primary Infection
Pupation
Phenological Calendar
As of May 13, 2026, Puget Sound stations range from 1906.2 to 2098.2 GDD₃₂. Radiant Crabapple has passed full bloom (1305 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 | Full bloom | — | — |
| Kent / Auburn | 2,089 | Full bloom | — | — |
| Seattle / UW | 2,063 | Full bloom | — | — |
| Olympia / Tumwater | 2,025 | Full bloom | — | — |
| Tacoma / Puyallup | 1,993 | Full bloom | — | — |
| Bellingham / Whatcom | 1,972 | Full bloom | — | — |
| Sequim / Rain Shadow | 1,906 | Full bloom | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| Beginning of flowering BBCH 61 | 990 | Late April (Puget Sound) |
| ● Full bloom BBCH 65 NOW | 1305 | Late April to early May (Puget Sound) |
Source: HortGuide regional interpretation based on Morton Arboretum bloom timing 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.
Diseases: Regionally Documented (3)
Diseases: Other Associations (1)
Pests: Regionally Documented (3)
Radiant is a hardy University of Minnesota introduction (1957) optimized for Rocky Mountain and Intermountain states where extreme cold and dry conditions stress most ornamental crabapples. In maritime PNW, Radiant's primary strength (Zone 3 cold hardiness) is largely surplus to need, and the cultivar's Poor scab rating per JFS is a meaningful regional liability — maritime PNW spring weather drives heavy scab pressure and Radiant will defoliate noticeably most years. Use Radiant in PNW landscapes only where: (1) extreme cold hardiness is genuinely needed (Cascade-foothill sites or occasional Zone 6-7 winter events), (2) the broad 25 × 20 ft rounded crown is specifically required, OR (3) excellent fire blight resistance is the priority. For routine PNW applications, modern cultivars like 'Prairifire' (Excellent across all four diseases, similar 20-ft size, deep pink-red flowers) offer substantially better disease performance. Cross-reference for PNW: 'Prairifire' (excellent across all four diseases, similar deep pink color, 20 × 20 ft) is the modern upgrade path.
— Chris Welch, ISA Certified Arborist