White fir

Botanical name

Abies concolor

Type

Native evergreen conifer

Height

Central Sierra Nevada trees reach about 140 to 180 feet

Trunk

Often 40 to 80 inches across in the Sierra

Lifespan

300 to 400 years

Elevation

California range 3,900 to 9,800 feet (USFS)

Property owners on the Nevada side of the lake, on Kingsbury Grade and on the upper Carson Range slopes live among white firs. They look like a solid green wall, until one turns red.

How do you identify a white fir?

Needles are flat, 1.2 to 2.8 inches long, and curve upward along branches that spread in flat, horizontal sprays. On young trees the bark is smooth and gray with resin blisters. On old trees it turns thick, hard and deeply furrowed into scaly ridges. Fir cones stand upright on the branch and fall apart on the tree, so you rarely see an intact one on the ground.

• Flat, curved needles in flat sprays
• Smooth gray bark with resin blisters when young
• Deeply furrowed ridges on old trunks
• Upright cones high in the crown

Where does white fir grow by elevation?

The Forest Service gives a California range of about 3,900 to 9,800 feet, which covers the Sierra side of Lake Tahoe. On the Nevada shore, Incline Village is near 6,400 feet, Zephyr Cove near 6,300, Glenbrook near 6,200 and Kingsbury near 7,100, all in or near USDA zone 6b. Precipitation there is far higher than in the valleys; the Glenbrook station records about 18 inches a year at 6,350 feet. A white fir in a Reno or Carson City yard at 4,500 to 4,700 feet is a planted tree living on irrigation.

What goes wrong with white fir?

Drought and the fir engraver go together. The Forest Service says fir engravers have attacked and killed white fir, especially drought-stressed trees after a disturbance, and that fire-weakened trees attacked by insects can die within a few years. See fir engraver. Top-down dieback is the sign to watch for.

Root disease is the second problem. FEIS reports that root diseases can make trees less wind-firm, and that root grafts between firs help root rot spread. A fir with a fruiting body at the base, or a stand where trees fall in a patch, needs an on-site look. See root and trunk decay.

Fire: young trees are highly susceptible, and mature trees are only moderately fire tolerant. Dense, low-limbed firs are a ladder for flames, see ladder fuels and limbing up.

When is pruning, cabling or removal the answer?

Dead limbs and hazards come off at any time. For other pruning, conifers are usually cut in early spring and summer; the useful cuts on a fir are deadwood, lower limbs that touch the ground or the roof, and branches too close to the chimney.

Removal is the usual answer for a dead tree, a crown that is mostly brown, decay at the base, a trunk that leans after wind, or a tree within falling distance of a house with a root problem. At Tahoe, check the permit rule first: TRPA regulates live trees over 14 inches DBH, and a dead tree that could fall on a house needs no permit. The agency decides. Our Tahoe permit guide shows how to measure.

Tall firs on steep Tahoe lots are often a job for crane-assisted removal. A certified arborist assesses every job first. For firewood, call the office.