How to Grow Rocky Mountain Juniper Trees

Close Up of Rocky Mountain Juniper

seven75/Getty Images 

In This Article

“Of the mountain” is the meaning of the botanical name for Juniperus scopulorum. While the Rocky Mountains are no stranger to slow-growing, drought-tolerant, soil adaptable species, what makes the rocky mountain juniper different is that, for one reason or another, the nursery trade has made many cultivars of the species commercially available to the public. That is terrific news for people who want to add this versatile conifer to their garden. 

Juniperus scopulorum is a tree that can play many roles in the garden landscape depending on your design, your setting, and your cultivar. The rocky mountain juniper is perfect for xeriscaping, sheltering and feeding wildlife, erosion control or as a windbreak.  As a bonus, it is a very pretty tree no matter the cultivar. 

Its normal form is unlike other junipers in that it is somewhat formal in shape. It reaches mature heights of 30 to 40 feet in a columnar shape with one or two main leaders or main “stems”. The foliage depends on the variety but ranges from dark green to blue-green. The needles on young plants are soft and short but become appressed and scale-like as the tree matures. Another shining feature is the rocky mountain juniper’s berry-like cone. The little fleshy cones ripen in their second year, are dark blue, covered in a whitish bloom, and have been used for food, medicine, and making all types of beverages from tea to gin.  

An impressive thing about the rocky mountain juniper is that these trees can live very long lives. One especially old specimen, the Jardine Juniper, was discovered in 1923 within the Cache National Forest. This ancient tree has been dated to be approximately 1500 years old. Proper planning needs to be done when planting this tree, as it is going to be around awhile.  

Botanical Name Juniperus scopulorum
Common Name  Rocky Mountain Juniper, Red Cedar
Plant Type Tree,  Shrub 
Mature Size  3- to 30 ft. tall,  spread of 3-15 ft
Sun Exposure Sun to Part Shade
Soil Type Sandy, Gravelly, Loose Rock
Soil pH Neutral
Bloom Time No Bloom
Flower Color No flower but shows blue to purple berry like cones.
Hardiness Zones 4-9a
Native Range Western North America from Texas to British Columbia
Toxicity No

How to Grow Rocky Mountain Juniper

Junipers are easy to grow and will be a great addition to any landscape if you are willing to invest the time that these trees take to come into their own. 

They grow slowly, and that it is the first thing that you need to consider. Plan your garden and decide why you want a rocky mountain juniper in it, - is it the right tree, the right size, in the right place, and are you choosing the right cultivar? Once you have decided that the rocky mountain juniper is what you want, go for it! 

Remember, it will last a good long time so be prepared for a long-living plant that spreads to about half the width of its height. If you are looking for a tall slender cultivar, you might want to choose Juniperus scopulorum ‘Blue Arrow’, this cultivar is often used as windscreens and hedges. 

To plant your tree, pick your location knowing the size, and the characteristics of your tree. Consider the utilities and any infrastructure under the plant and think about future improvements.

Once a site is chosen, dig a hole twice as wide as your tree’s root ball, or container, and just as deep. Remove the tree from the container or burlap and set it in the hole. Maintain it in an upright position as you fill the hole and compress the soil. Lightly mulch to a depth of three inches to the dripline of the tree making sure that no mulch touches the trunk of the tree itself. 

If your tree is in a windy spot, consider staking it to ensure that it remains upright.

Light

The rocky mountain juniper prefers full sun but will take to part shade. Like all junipers, it is pretty adaptable.

Soil

The ideal soil for this tree is a loose, inorganic mix that is neutral. Adding vermiculite, perlite or a pumice mixture is perfect if you are looking to amend your soil to give it texture to help your juniper.

Water

The tree does not require much watering and is very drought-tolerant. As mentioned, this plant is perfect for xeriscaping or other waterwise gardens.

Temperature and Humidity

This plant prefers warm dry temperatures, but it is cold hardy to -35 degrees Fahrenheit. 

Fertilizer

The rocky mountain juniper does not require feeding.

Is Rocky Mountain Juniper Toxic?

The Rocky Mountain Juniper is not toxic. It is actually used for traditional medicines, herbal teas, and Native American folk cooking.

Potting and Repotting Rocky Mountain Juniper

In the United States, the rocky mountain juniper is a favorite for the bonsai enthusiast. To create a bonsai using a rocky mountain juniper, there are many dwarf or miniature cultivars available that are perfectly suited for bonsai creations.

Juniperus scopulorum ‘Snow Flurries’ is an especially nice, variegated cultivar. You need to transplant it into a pot just large enough for its roots with a premixed bonsai soil that will consist of inorganics such as pumice, vermiculite, and crushed lava. Occasionally, pine bark is also included. 

Once established for a few years, you can re-pot to a larger pot by removing the soil from the roots and trimming and shaping the tree into your own unique work of art.