Acer glabrum

Common Names

Rocky Mountain Maple, Douglas Maple, New Mexico Maple, Rock Maple, Mountain Maple, Greene's Maple, Torrey Maple, Dwarf Maple, California Mountain Maple, Sierra Maple

Summary

Rocky Mountain Maple is a western North American deciduous shrub or small tree, typically 12–30 ft tall with a multi‑stem or single‑trunk form and smooth gray bark when young; leaves are palmately lobed (3–5 lobes), flowers are greenish‑yellow in spring, and fruits are winged samaras, with autumn color ranging from yellow to red and habitat along stream banks and moist sites in conifer forests.

Preferring moist, well‑drained soils, it grows best in full sun to part shade and tolerates sandy, loamy, and heavy clay soils with moderate drought tolerance once established; irrigation may be needed in hot, dry periods. It provides erosion control and woodland‑garden value as an understory tree, supports wildlife (browse for moose, elk, and deer; nectar for native bees), and features wind‑dispersed seeds and root‑crown sprouting after disturbance; seeds require chilling to germinate, and nursery stock is available; prune in summer after leaf development to avoid sap bleed; hardiness zones 3a–8b.

Lifecycle

Perennial

Height

12-30 feet

Spread

10-20 ft

Hardiness Zones

Zones 4–8

Sunlight Requirements

Ideally full sun, tolerates partial sun to partial shade.

Soil Type

Loamy, well-drained soil

Soil Drainage

Moist, well-drained soils.

Soil pH

5.8–7.5, slightly acidic to neutral, tolerates moderate alkalinity

Bloom Color

Insignificant

Bloom Time

Spring (April–June, varies by elevation)

Foliage Color

Green

Fall Foliage Color

Yellow, orange and red

Leaf Lifecycle

Deciduous

Growth Rate

Moderate; 1-2 ft per year

Seasons of Interest

Spring and Fall

Propagation Methods

Seeds, Cuttings, Layering, Micropropagation, Root crown sprouts/suckers

Attracts Wildlife

Bees, butterflies, other pollinators, and birds are attracted