Virginia spiderwort
Tradescantia virginiana
Commelinaceae · [VERIFY] · native
Last updated
Virginia spiderwort is a native perennial reaching 1-3 ft with an upright growth habit. It blooms May to July with three-petaled flowers and has linear, lance-shaped foliage. Plants spread naturally through rhizomes.
Virginia spiderwort is hardy in zones 3a-8b and tolerates clay, wet soil, and black walnut. It attracts bees, butterflies, and pollinators while being poisonous to humans and problematic for pets. Growth is medium-paced with moderate maintenance in moist conditions.
Quick Facts
Phenological Calendar
As of April 19, 2026, Puget Sound stations range from 1342.9 to 1500.8 GDD₃₂. Virginia spiderwort typically reaches beginning of flowering at 1877 GDD₃₂, predicted around May 7.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 19, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,501 | Pre-season | Beginning of flowering | 376 |
| Seattle / UW | 1,465 | Pre-season | Beginning of flowering | 412 |
| Kent / Auburn | 1,441 | Pre-season | Beginning of flowering | 436 |
| Olympia / Tumwater | 1,415 | Pre-season | Beginning of flowering | 462 |
| Bellingham / Whatcom | 1,390 | Pre-season | Beginning of flowering | 487 |
| Tacoma / Puyallup | 1,381 | Pre-season | Beginning of flowering | 497 |
| Sequim / Rain Shadow | 1,343 | Pre-season | Beginning of flowering | 534 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ Beginning of flowering BBCH 61 NEXT | 1877 | — est. May 7 (avg) |
| Full bloom BBCH 65 | 2630 | — est. Jun 7 (avg) |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Source GDD₅₀ thresholds from Herms 2004 (OSU, Secrest Arboretum, Ohio) and UMD IPMnet (Gill & Klick, mid-Atlantic), converted to GDD₃₂ via Kent bloom-date mapping. Season tracker for Kent / Auburn as of Apr 19, 2026. Predicted dates use 16-day weather forecast through May 5, 2026, then climate normals.