Explorer’s gentian blooms with it’s striking deep blue to purple flowers late summer to early fall as part of the last wave of wildflowers in the high country of the Klamath-Siskiyou region. We usually see it start to bloom in late August to early September, depending on the snow year. Known by the additional common names, mountain bog gentian or Rainier pleated gentian, this herbaceous perennial has a wide range across the mountainous regions of the West, from the Canadian Cascades in the north, to the Sierra Nevada in California, where it can be found growing in bogs, fens, wetlands, moist meadows, moist rocky habitat, red fir forests, lodgepole forests, subalpine forests, and along moist river or creek banks at mid to high elevations. It is adapted to grow on various soil types, including serpentine, but is more often than not growing in loamy or clay soils, often punctuated with rock.
Explorer’s gentian is a mounding species that typically grows 6-18″ tall when in flower. Explorer’s gentian has thick green leaves growing along prostrate to upright stems. The vibrant, deep blue, bell shaped flowers have five petals that are often decorated with pale yellow to white spots and are pointed at the tips. Between the petals are triangular, pointed appendages. The flowers are highly attractive to a wide range of pollinators, including late season bumble bees, flies and wasps.
This species is highly sought-after for native rock gardens, but it can be a little tricky to grow from seed. Be sure to surface sow the seeds. Don’t cover the seeds with soil. The seeds will need a long duration of cold-moist stratification.
Explorer’s gentian can be grown in full sun to shade, depending on elevation. At lower elevations it will prefer some shade. At higher elevations it can be grown in full sun. It requires regular moisture.
Explorer’s gentian (Gentiana calycosa) seed packets contain approximately 225 seeds per packet.
Seed Germination Instructions
120 days cold-moist stratification. Surface sow, don’t cover the seeds with soil. Sow outside in fall to early winter and let nature do the work if you live in a cold enough area, or in areas with mild winters, artificial methods may be needed.