Abstract
Big sagebrush (Artemisia tridentata Nutt. [Asteraceae]) is an essential component of shrub-steppe ecosystems in the Great Basin of the US, where degradation due to altered fire regimes, invasive species, and land use changes have led to increased interest in the production of high-quality big sagebrush seedlings for conservation and restoration projects. Seedling storage is an important consideration in the production of high-quality planting stock, yet little is known about optimal storage conditions for this species. Our survey of nurseries in western US found that only 13% of those that grow big sagebrush in containers use cooler or freezer storage to maintain seedling quality. Of those nurseries, 80% rely on cooler storage. We tested cooler (2 to 4 °C) and freezer (0 to –2 °C) storage of big sagebrush in late spring and found that 2 mo of freezer storage reduced survival after transplanting from 96 to 78%, but seedling growth was unaffected. This suggests that seedlings may be more susceptible to freezer conditions because of reduced cold hardiness in spring, but that either storage temperature maintains seedling vigor. Future work is needed on big sagebrush to determine the appropriate hardening regime and lifting dates for freezer storage.
