Foreground: Juniper loaded with berries. Background: Henderson Conservation Easement along the Bear River with the northern Wasatch mountains beyond.
If one tree defines Pocatello it would have to be the juniper. Junipers dot our hillsides and push against homes sprouting in their territory. They are so common that we take them for granted, but junipers are interesting trees. Junipers are often called cedars — a good example of just how confusing common names can be. True cedars are in the Pine family. Junipers are in the Cypress family.
Two species of tree-sized junipers are native here. Utah juniper (scientific name Juniperus osteosperma) is the most common. It is a stiff, stubby tree. The scale-like leaves feel coarse — like potscrubbers. The berry-like cone (which takes two years to mature) contains one and sometimes two seeds. Scratching the blue blush from older cones exposes a reddish brown cover beneath.
| Rocky Mountain juniper (Juniperus scopulorum) has a finer-textured appearance, but the branches feel pointed and prickly. Each berry-like cone holds two seeds — sometimes one. Because Rocky Mt. juniper generally bears male and female cones on separate trees, berries will be found only on the female trees. It has a larger range than any other juniper species in the West, but it is not as common around Pocatello as Utah juniper. The nursery trade has developed many varieties of Rocky Mt. juniper including Skyrocket and Wichita Blue.
Both junipers grow slowly. Rocky Mt. Juniper grows 0.79 inch in diameter per decade until it reaches 170 years old. Thereafter the growth rate declines to a rate of 0.255 inch in diameter per decade after 250 years of age! Utah juniper reaches 25 feet tall, and Rocky Mt. juniper rarely exceeds 35 feet.
Rocky Mt. juniper typically lives 250-300 years, although Old Juniper in Logan Canyon is believed to be 3,000 years old. Utah juniper may live as long as 650 years and begins to produce seed only when about 30 years old. The seeds are so long-lived that, in one study, 17% of Utah juniper seeds germinated after 45 years.
Junipers are very drought tolerant. They can push a taproot deep into the soil, but it is the lateral roots, which extend as far as 100 feet from the tree and just several inches below the surface, that collect most of the tree’s needed moisture.
If you are fortunate enough to have native junipers around your home, remember that they are very flammable. So keep them a safe distance from your home’s structure. And remember that they do not need, nor appreciate, extra water.
Article by land trust member and volunteer Sandra Thorne-Brown. |
