Jeffrey pine

Botanical name

Pinus jeffreyi

Type

Native evergreen pine

Height

Up to about 200 feet

Trunk

Up to about 8 feet across reported

Lifespan

Often 400 to 500 years

Where it grows here

Western Nevada and the Lake Tahoe region, about 5,000 to 7,800 feet in Nevada (USFS)

If your property is on the Nevada side of Lake Tahoe or on the slopes above Washoe Valley and Reno, the pines in the yard are very likely Jeffrey or ponderosa. They look alike from the road, and the difference matters less than the condition of the tree.

How do you identify a Jeffrey pine?

Count the needles in each bundle: Jeffrey pine has three, in long, stiff, gray-green bundles. The bark is thick, in large plates separated by deep furrows. The cones are the clearest clue between the two common big pines, because Jeffrey pine cones are large, roughly 5 to 12 inches long, bigger than the cone of a ponderosa.

• Needles in bundles of three
• Large cones, about 5 to 12 inches long
• Thick bark in big plates with deep furrows
• Open, tall crown on mature trees

Where does it grow by elevation and zone?

The Forest Service gives a Nevada range of about 5,000 to 7,800 feet. That covers the Tahoe basin towns: Incline Village is near 6,400 feet, Zephyr Cove near 6,300 and Kingsbury Grade near 7,100, all in or near zone 6b on the USDA map. It also covers the Carson Range slopes above Washoe Valley, which sits near 5,100 feet. The valley floors of Reno and Carson City, at 4,400 to 4,700 feet, are below the usual range, and a Jeffrey pine there is usually a landscape planting that needs steady water.

At Tahoe elevations, precipitation is much higher than in the valleys. The Glenbrook station records about 18 inches a year at 6,350 feet, compared with about 7 inches at Reno-Tahoe International Airport at 4,410 feet.

How big does it get, and how does it behave in a fire?

It can reach about 200 feet and live for 400 to 500 years. The Forest Service calls adults moderately to highly fire resistant because of their thick bark, and they often survive low-intensity surface fires. Severe surface fires and crown fires can still kill them.

In a yard, resistance depends on what is underneath. Brush, dead needles and low limbs let a ground fire climb into the crown, which is why limbing up and clearing around the trunk are part of defensible space work.

What goes wrong with Jeffrey pines here?

Bark beetles and drought are the main killers. In one Forest Service study cited by FEIS, two beetle species attacked 31 percent of trees on Spooner Summit after a prescribed burn, and drought and beetle attack are named as main causes of mortality in another region. Signs to look for are pitch tubes on the trunk, fine reddish dust at the base and a crown that fades from green to yellow to red. See bark beetles in pines.

Heavy snow can break limbs, and a tree that has lost a lot of crown to a storm can be weakened for years. Dead pines are a fire hazard as well as a falling hazard, see removing dead pines.

When is pruning, and when is removal, the answer?

Dead branches and hazards can be removed at any time. Otherwise, conifers are usually pruned in early spring and summer. Pines do not need much shaping; the useful cuts are deadwood, lower limbs that carry fire up, and branches over the roof.

Removal is usual for a tree that is dead or has a crown that is mostly red or brown, a trunk with a lean that has changed, or large decay at the base. At Tahoe, check the permit rule before anything comes down: TRPA regulates live trees over 14 inches DBH, and the Tahoe permit guide explains how to measure. The agency decides, not us. Wood from a removed pine can be hauled away; for firewood and chips, call the office.