Curl-leaf mountain mahogany

Botanical name

Cercocarpus ledifolius

Type

Native evergreen shrub or small tree

Size

3 to 35 feet tall (USDA Forest Service)

Elevation

About 1,200 to 3,000 meters (roughly 3,900 to 9,800 feet) in California; 1,500 to 3,000 meters in the Great Basin (USDA Forest Service)

Where it is found

Dry, rocky, steep slopes on the foothills and Carson Range above the valleys

Known weak points

Killed by most fires, weak resprouting, very slow recovery

This is a wild tree of the hills around our valleys, not a nursery tree. It grows with sagebrush, pinyon and juniper, in thin rocky soil. The USDA Forest Service describes it as slow-growing, drought tolerant and long-lived. This page covers identification, where it grows by elevation, what changes after fire and when pruning or removal makes sense.

How do you identify curl-leaf mountain mahogany?

The leaves are small, one to four centimeters long (under about an inch and a half), thick, leathery and resinous, with edges curled under and a pale hairy underside. They are clustered at the ends of short stubby twigs. In summer and fall the seeds carry long, feathery, corkscrew tails, which give the tree a silvery look.

Young plants are shrubby, branched close to the ground. Old ones can be small, gnarled trees with dense crowns and dark, furrowed bark.

• Small, thick, leathery leaves with curled edges
• Feathery seed tails
• Dense, gnarled crown
• Gray-green evergreen foliage on rocky slopes

Where does it grow around Reno, Carson City and Tahoe?

The Forest Service gives its range as about 1,500 to 3,000 meters in the Great Basin and 1,200 to 3,000 meters in California, which is roughly 3,900 to 9,800 feet. It grows between the lower conifer belt and desert steppe, on dry, steep, rocky slopes with well-drained, nutrient-poor soil. In our area that means the dry flanks of the Carson Range and the hills above the Truckee Meadows and Carson Valley, rather than the planted valley lots.

You may find it near Galena and Mount Rose (5,634 feet) or Kingsbury (7,126 feet) only on slopes with the right rock and exposure. It is not found on irrigated lawns.

What goes wrong with it here?

It is a tough, native plant, and in drought it does well. The main hazard is fire. The Forest Service says it is usually killed by fire, though thick bark lets some mature trees survive light fires where litter is low, and that resprouting is weak. Seed banks survive low and moderate fires, but recovery can take decades. Its wood burns long and hot, even though stands with sparse fuels rarely burn.

For a home on one of these slopes, the fire question is spacing and ladder fuels, not the health of the mahogany. Our defensible space guide and wildfire risk guide cover how an arborist plans a thinning.

Pruning, cabling or removal: which is the right call?

Pruning a mountain mahogany is mostly a defensible-space cut: limb up lower branches near the ground where they could carry fire into a taller shrub or tree, and remove dead wood. It is slow-growing, so heavy cuts take years to grow back. Taking out a whole old stand is a different decision, and a native plant of this age deserves a second look before it goes.

Removal fits when a tree or thicket sits inside the first few feet of a house or on a driveway edge, or when it crowds a fire break. Brush that thick is often a defensible space or masticating job. The Living With Fire guide from UNR Extension sets Zone 0 at 0 to 5 feet, Zone 1 at 5 to 30 feet and Zone 2 at 30 to 100 feet.

What does Battle Born Tree Service do about mountain mahogany?

We look at the whole tree, not only the part that worries you, and the free estimate lays out limbing up, thinning or removal. The crew is eight people, two of them ISA Certified Arborists, and the phone line is staffed seven days a week at 775.232.8243. The arborist will tell you if the plant is better kept.