Propagation and population re-establishment for tall bugbane (Cimicifuga elata) on the Salem District, BLM

Background:
Tall bugbane is a Bureau of Land Management Special Status species that occurs in forest habitats west of the Cascade Range in British Columbia, Washington, and Oregon. To maintain the viability of this species, an interagency Conservation Strategy (Wogen et al., 1996) calls for monitoring throughout the plant’s range on USFS, BLM, and ACOE lands in Oregon and targeted research on population enhancement techniques.

Objectives:
The specific objectives of this cooperative project were to develop propagation

techniques for tall bugbane and re-establish the species at the Humdinger site. The propagation phase focused on developing germination techniques for the species and attempting greenhouse cultivation. Field transplanting for re-establishment centered on evaluating fertilizer as a tool to improve transplant success, contrasting spring and fall transplanting seasons, and comparing growth of plants from two source populations.

Findings:

1. Seed germination of this species requires warm stratification (15°C/25°C) for 2 weeks followed by cold stratification (5°C) for 3 months. After that, seeds placed in an environment of alternating warm temperatures (15°C/25°C) germinate up to 96%, depending on the source population.
2. Plants grown from seed in potting soil in a greenhouse environment grow well and have high survival. A potting medium amended with commercial mycorrhizae, however, yielded poor survival.
3. Survival of field transplants at the Humdinger site was significantly affected by season of planting, with fall (2000) transplants having higher survival (82%) into the second season of growth (2001) than spring (2000) transplants (59%).
4. Herbivory by deer and mountain beaver was very high. Most plants were damaged to some degree; on average, 27% to 80% of plant tissue was eaten, depending on seed source, season of planting and whether or not plants were fertilized.

Conclusions:

1. Tall bugbane can be cultivated in a greenhouse environment (ex situ).
2. Plants may be out-planted to field sites, but damage from herbivores may be high.
3. Continued monitoring to document second and third year survival will benefit this project.
4. Further research is needed to explore the success of techniques (such as application of pepper extract) to reduce herbivory on transplants and increase plant survival and growth.