Juniperus scopulorum - Rocky Mountain juniper

Rocky Mountain juniper grows throughout the mountainous areas of western North America, mainly above 1500 metres elevation. In places it forms large thickets giving a characteristic appearance to the landscape. It can grow into an erect, pillar-shaped or conical tree to 10 metres, or an irregular round shrub with strong branching from the base.

Rocky Mountain juniper has two kinds of leaves, one kind being needle-like, the other scale-like and pressing close to the branches. Their colour varies from dark blue-green to a dull grey-green. The species is usually dioecious, i.e. each individual is either male or female. The berry-like cones borne by the females are roundish, clear blue, with a surface bloom. This species is extremely long-living: a tall tree-like specimen found in New Mexico had 1888 annual rings.

Rocky Mountain juniper’s hardiness in Finland has not been properly tested. Those plants grown here are usually pillar-shaped or other attractive varieties, which at Mustila seem to thrive better than the wild species. The most commonly grown variety in Finland is probably ‘Skyrocket’, often named J. virginiana. 'Blue Arrow', 'Moonglow', 'Silver Star', 'Springbank' and 'Wichita Blue' are other varieties planted at the Arboretum.