At a Glance
Height: 20-40 feet but can reach 50 feet in places with excess moisture
Spread: 3-15 feet
Shape: Pyramidal or conical with a pointed top, becomes more irregular as it ages
Exposure: Full Sun
Leaves: Blue-green needle-like foliage made up of triangular scales
Fruit: Silvery blueberries
Bark: Reddish-brown to gray, strips come off as the tree ages
Where to Plant: Works well as an accent tree or for hedges or windbreaks. Should not be planted under powerlines or too close to buildings. Needs full sun, can’t tolerate standing water, works well in drought situations.
Common Problems & Possible Causes
Chocolate-colored, kidney-shaped galls on the upper or inner foliage surface – Juniper-hawthorn rust, cedar-apple rust
All About the Rocky Mountain Juniper
The Rocky Mountain Juniper (Sabina scopulorum) (Sargent) Rydberg, was previously categorized as (Juniperus scopulorum). It’s also known as a cedar tree, juniper bush, Colorado redcedar, or Rocky Mountain cedar.
Where it Grows
Scopulorum means “of the mountains,” which is where the Rocky Mountain juniper is found. It typically grows on the eastern slopes above 5,000-foot elevation, but it can also be found on many hillsides, especially in Western Colorado.
Three different kinds of juniper trees are found throughout Colorado, but the one you will find most often in our area is the Rocky Mountain Juniper. It’s found naturally from British Columbia all the way south through Texas.
The Rocky Mountain juniper is the tallest of the junipers, growing up to 30 to 40 feet tall. However, its height is influenced by the amount of available moisture. In conditions with more moisture, it may reach 50 feet in height; in a dry location, it may only reach a height of 15 feet.
A slow-growing tree, a Rocky Mountain juniper can take 40 years or more to reach a height of only 14 feet! However, this greatly depends on how much water the tree receives.
Rocky Mountain junipers in home landscapes can live for 70 years for more in the right conditions. In the wild, it can grow for 250 to 300 years or more.
Junipers can be distinguished from other evergreen trees by their scale-like needles, their reddish-brown bark, and by the blue-gray berry-like fruit.
The “berries” on Rocky Mountain junipers are actually miniature cones, the scales of which grew together and combined to form a berry-like shape. If you rub the blue coating off the berries, they will be green underneath. It takes about 2 years for the berries to mature, so they will be on the tree for a while.
Juniper berries are an important food source for many forms of wildlife, including birds. The birds eat the berries and the seed passes through their digestive system unharmed, allowing the seeds to be distributed far and wide.
Berries may not appear on Rocky Mountain junipers for the first 10 years – but a 10- year-old tree is likely only about a foot tall.
It needs little or no pruning and grows in a natural pyramidal shape, getting slightly more irregular as it ages.
Some animals may eat the bottom branches of the tree, especially when the tree is young or newly-planted.
Young junipers (up to 20 years old) are easily killed by fire due to their thin bark and compact crown. Older juniper trees may survive surface fires but not severe fire.
Overall, Rocky Mountain juniper is relatively free of serious insect and disease problems. Although it’s the alternate host for the juniper-hawthorn/cedar-apple rust disease, it does very little harm to the tree.
The strong and highly aromatic wood from juniper trees is used to make cedar chests, fence posts, and other items. Many parts of the juniper tree were and still are used for a variety of purposes. For example, the berries have been used to treat asthma, ingested either whole or brewed as a tea. Juniper leaves, combined with other ingredients, were boiled and made into a paste as a treatment for arthritis.
The Rocky Mountain juniper tree is a popular ornamental tree and is useful as part of a privacy screen or for wind protection.
When determining what tree might work best for your property, keep in mind that there are many cultivars of Rocky Mountain juniper available for sale. Some, like the cultivars ‘Skyrocket’ and ‘Blue Arrow,’ are more slender and are often used as ornamental trees in gardens. Other popular cultivars include ‘Green Ice,’ ‘Jewell Frost,’ Blue Weeping,’ and ‘Cologreen.’ Note the specific attributes of a cultivar before choosing one or more for your property – they can vary widely on mature size, pest issues, and landscaping needs.
Contact LAM Tree Service if you have any questions about how to care for your Rocky Mountain juniper trees.
We recommend spring or early fall planting to get your new trees off to a great start. You can always call us for advice on where to plant your new tree(s) and don’t forget that we offer professional tree planting services if you don’t want to do it yourself!
Recommended Trees & Shrubs
Get A Free Quote
Call us at 303-674-8733 or contact us online to get a free estimate for tree planting, general tree services or any aspect of our Plant Health Care program.