Rocky Mountain juniper is generally monoecious although rarely dioecious. Rocky Mountain juniper is characterized by a long lifespan and slow growth rate. However, some plants can survive much longer. Regeneration in Rocky Mountain juniper is through seed. Heavy seed crops occur at two to five year intervals.
Seed can remain viable for some time.
Seed of Rocky Mountain juniper is dispersed primarily through birds and large or small mammals. Gravity and water can also serve as dispersal agents. Rocky Mountain juniper does not reproduce vegetatively. Rocky Mountain juniper occurs at a wide range of sites which vary significantly in soils, elevation, and climatic factors. Stand structure and associated plant species are also highly variable.