Effects of seed source and pre-planting treatment on emergence of Juniperus scopulorum Sarg. in a Great Plains nursery

Reliable propagation of Rocky Mountain juniper (Juniperus scopulorum Sarg. [Cupressaceae]) for use as an evergreen shelterbelt species in the southern Great Plains is hindered by inconsistent seedling emergence and establishment. We evaluated a series of pre-planting treatments as well as 2 planting depths for both fall and spring planting dates using a single seed source. We then tested 6 seed sources using the 3 best treatments. The best treatment was 13 wk at 22 °C (72 °F) followed by 13 wk at 4 °C (39 °F; 23% emergence for fall and spring planting combined). Fall planting resulted in greater success for differing pre-planting treatments. Planting depth did not affect emergence. Only one of 6 seed sources produced seedlings in response to cold-only treatment while combining warm and cold treatments was generally successful for all seed sources.