Rocky Mountain Bristlecone Pine (Pinus aristata)

At a Glance

Height: 9 to 40 feet

Spread: 10 to 15 feet

Shape: Twisting, with rounded, flattened, or irregular crown

Exposure: Sun

Native? Yes

Evergreen? Yes

Leaves: Long-lasting (sometimes for decades) clusters of needles, usually with white resin flakes. Needles are in bundles of five and are 1-1 ½ inch long. Because the needles stay for such a long time, the branches can end up resembling a bottle brush.

Fruit: Distinctive “prickly” cones – purple shade fades to brown as they mature.

Firewise? No. Can survive low severity fires but not severe ones

Drought-tolerant? Yes. Overwatering or standing water can kill the bristlecone pine.

Bark: Red-brown, gray on older trees

Where to Plant: Grows in the wild on dry, rocky slopes. Suitable for sandy and loamy soils, well-drained, cannot grow in shade

Common Problems & Possible Causes

Needles turn a rusty color White Pine Blister Rust (Phoradendron pauciflorum)

Sap and/or pitch masses on bark, branch dieback – Mountain Pine Beetles (drought conditions have made bristlecone pines more susceptible to pine beetles)

General decline, particularly when grown in moist soil or standing water – Root decay

Close-up of bristlecone pine showing the characteristic white flakes from resin

This close-up of bristlecone pine shows the characteristic white flakes from resin
Photo by Hans G. Oberlack – Own work, CC BY-SA 3.0,

About Bristlecone Pine


There are three species of bristlecone pines:

  • Great Basin Bristlecone Pine (Pinus longaeva, meaning long-lasting),
  • Rocky Mountain Bristlecone Pine (Pinus aristata, meaning “beard,” referring to the bristles on the pinecones), and
  • Foxtail Pine (Pinus balfouriana)
map showing distribution of Rocky Mountain Bristlecone Pine in the wild

The native distribution of Rocky Mountain bristlcone pine covers only a small part of the country


Each is found in different sections of the Western United States, but only the Rocky Mountain bristlecone pine (Pinus aristata) is found in Colorado. The Rocky Mountain bristlecone pine can also be found in the higher elevations of Arizona and New Mexico.


These rare trees are known for their longevity in the wild, so while there may not be many of them, they can live for a long time.

You may have heard of the famous bristlecone pine tree in California named “Methusela,” thought to be the oldest tree in the world. The location is kept secret to protect the aged tree. While Methusela is a bristlecone pine, it is not the kind found here in Colorado.


The bristlecone pine gets its name from the pinecone, which has a bristle-like appearance. The clusters of needles can often have a bottlebrush-like appearance because of how long they stay on branches.


The easiest way to differentiate a Rocky Mountain bristlecone pine from the other types is to look for white flaking on the needles. This white resin, which often looks like dandruff, is from broken needles. Keep in mind, however, that scale insect infestations can often cause a dandruff-like look as well, so be sure to consult with an arborist if you’re not sure.

Growth Rate

All bristlecone pines are incredibly slow-growing. Slow-growing trees tend to mean strong and long-lasting, and that’s particularly true in this case. However, this strength and longevity are more often seen in bristlecone pines growing in natural settings, rather than in landscaped yards.

In the wild, bristlecone pines are thought to grow slowly because of cold weather, high winds, dry soils, and short growing seasons.

How slowly?

Well, depending on the weather, they can grow only 1/100th of an inch a year! They also have been known to not add any rings to their trunk during seasons of drought, and the other growth rings can be incredibly narrow.

The reason for this may be that bristlecone pines thrive in environments that are not often found in landscaped areas. They’re most often found on rocky ground, usually on a southern-facing slope, and typically grow at higher elevations (between 7,000 to 13,000 feet).

When not grown in the wild, the bristlecone pine may live close to 100 years but is often lost to root decay thanks to warm and moist conditions. Due to the recent drought conditions, mountain pine beetles are also a danger to these gnarled old trees.

How to Add a Rocky Mountain Bristlecone Pine to your Property

bristlecone pine specimen

Photo by Tom DeGomez, University of Arizona,

Bristlecone pines can only survive in full sunlight, so first check that your property has a spot that receives more than 8 hours of sun a day.

The soil should also be well-drained, as the tree can die in standing water.

As a medium-height tree, it doesn’t need too much room to grow, but keep in mind that it will continue growing for many years so can outgrow some smaller areas. Assume that it will grow to at least 40 feet tall.

Generally, bristlecone pines don’t need too much maintenance but look out for the signs of mountain pine beetle or white pine blister rust.

Learn More

Want to learn more about where to see some of the oldest bristlecone pines in Colorado?

Check out this article about the Mount Goliath Natural Area – where one tree is thought to be at least 2,461 years old. You might also want to visit the Windy Ridge Bristlecone Pine Scenic area.


Tree Planting

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!

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