For the last 50 years Wilbur L. Bluhm has recorded the timing of important phenological events such as the start and end of flowering, leaf out, the start of fall color, and leaf fall for nearly 2000 separate taxa in western Oregon.  The resulting dataset provides a remarkably comprehensive and long term picture of perennial plant phenology in the Pacific Northwest.

The core data were collected during standardized weekly censuses in and around Salem, OR beginning in 1995, but records for some taxa go back to the early 1960’s. The taxonomic focus is on perennial ornamentals and includes a diverse range of common cultivars for important groups such as maples, rhododendrons, roses, and viburnums. It also includes 250 west coast native taxa.

Taxonomic distribution among growth forms

  • 349 trees
  • 709 shrubs
  • 603 herbaceous perennials
  • 233 bulbs, rhizomes, and tubers
  • 64 vines
  • 25 ground covers
  • 8 annuals and biennials