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Acer glabrum is often confused with:
Acer rubrum Acer rubrum
Native alternative(s) for Acer glabrum:
Acer rubrum Acer rubrum
Plants that fill a similar niche:
Quercus nigra Quercus nigra
Ulmus alata Ulmus alata
Ulmus americana Full Form
Acer glabrum has some common insect problems:
Common Insect Pests of Maple in North Carolina
Acer glabrum has some common disease problems:
Common Disease Pests of Maple in North Carolina

Rock Maple Acer glabrum

Previously known as:

  • Acer glabrum subsp. typicum
  • Acer glabrum var. typicum
Phonetic Spelling
AY-ser GLAH-brum
Description

Rocky Mountain maple is a deciduous shrub or small shade tree in the maple family (Sapindaceae) and is native to western North America from Alaska south to California and west to Nebraska and south to New Mexico.  The specific epithet means smooth, without hair, referring to its smooth stems and leaves. The species is named after David Douglas, a Scottish botanist who in addition to this tree, is also known for the Douglas fir.

This tree will grow 12-30 feet in height and spread 10 to 20 feet wide. It usually has a multi-trunk habit and a shrub-like growth and a narrow crown in more open areas. It can be tall and spindly in closer stands of trees. Can withstand sandy, loamy, and heavy clay acidic soils, prefers well-drained soil and needs lots of organic matter. It performs best in semi-shade to shade. Plant in a location sheltered from strong winds, frost, and afternoon sun. This is a relatively low-maintenance tree, and should only be pruned in summer after the leaves have fully developed, as it may 'bleed' sap if pruned in late winter or early spring.

There are three varieties depending on what region they are growing in. They are listed below.

It is primarily grown for its ornamental red fruit in the late summer and fall and its interesting red twigs that stand out, particularly in the winter. The fall color is knock-out yellow-to-red.  

Works well for erosion control, in a woodland garden and as an understory tree. Best grown in its native habitat and would not be appropriate for the southeast.

Insects, Diseases, and Other Plant Problems: No significant insect or disease problems.  In alkaline soils, it can develop manganese chlorosis. Watch for aphids, leafhoppers, borers, scale, and caterpillars. Also note that verticillium wilt attacks the vascular system and can be fatal. Canker, fungal leaf spot, and root rots may also occur. Wind and ice may break some branches.

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common maple diseases and insect pests.

 

See this plant in the following landscape:
Cultivars / Varieties:
  • var. diffusum
    Found in dry mountain slopes
  • var. douglasii
    Found coastal southeast Alaska and British Columbia, to southern Oregon; east to Idaho and Montana.
  • var. glabrum
    Variety found in non-coastal regions of the west.
var. diffusum, var. douglasii, var. glabrum
Tags:
#deciduous#small tree#shade tree#samaras#shade garden#cover plant#low maintenance#winter interest#fall interest#erosion control#small mammals#fast growing#nighttime garden#children's garden#red fruits#red stems#pollinator plant#nesting sites#multitrunked#larval host plant#fall color yellow#clay soils tolerant#bird friendly#fall color red#butterfly friendly#imperial moth#wildlife friendly#woodland
 
Cultivars / Varieties:
  • var. diffusum
    Found in dry mountain slopes
  • var. douglasii
    Found coastal southeast Alaska and British Columbia, to southern Oregon; east to Idaho and Montana.
  • var. glabrum
    Variety found in non-coastal regions of the west.
var. diffusum, var. douglasii, var. glabrum
Tags:
#deciduous#small tree#shade tree#samaras#shade garden#cover plant#low maintenance#winter interest#fall interest#erosion control#small mammals#fast growing#nighttime garden#children's garden#red fruits#red stems#pollinator plant#nesting sites#multitrunked#larval host plant#fall color yellow#clay soils tolerant#bird friendly#fall color red#butterfly friendly#imperial moth#wildlife friendly#woodland
  • Attributes:
    Genus:
    Acer
    Species:
    glabrum
    Family:
    Sapindaceae
    Life Cycle:
    Woody
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Western North America
    Distribution:
    Alaska, Alberta, Arizona, British Columbia, California, Colorado, Idaho, Mexico Northeast, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Utah, Washington, Wyoming, Yukon
    Wildlife Value:
    Members of the genus Acer support Imperial Moth (Eacles imperialis) larvae which have one brood per season and appear from April-October in the south. Adult Imperial Moths do not feed. Food and shelter to wildlife
    Play Value:
    Attracts Pollinators
    Pieces Used in Games
    Wildlife Cover/Habitat
    Wildlife Food Source
    Wildlife Nesting
    Particularly Resistant To (Insects/Diseases/Other Problems):
    erosion
    Dimensions:
    Height: 12 ft. 0 in. - 30 ft. 0 in.
    Width: 10 ft. 0 in. - 20 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Shrub
    Tree
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Multi-trunked
    Rounded
    Spreading
    Growth Rate:
    Rapid
    Maintenance:
    Low
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Dappled Sunlight (Shade through upper canopy all day)
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Clay
    High Organic Matter
    Loam (Silt)
    Sand
    Soil pH:
    Acid (<6.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Very Dry
    USDA Plant Hardiness Zone:
    3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Green
    Pink
    Red/Burgundy
    Display/Harvest Time:
    Fall
    Summer
    Fruit Type:
    Samara
    Fruit Length:
    < 1 inch
    Fruit Description:
    Red winged samaras. This plant has green, insignificant flowers in April, which are pollinated by insects and followed by showy red winged samaras in late summer. Plant is dioecious.
  • Flowers:
    Flower Color:
    Green
    Flower Inflorescence:
    Cyme
    Insignificant
    Flower Value To Gardener:
    Fragrant
    Flower Bloom Time:
    Spring
    Flower Size:
    < 1 inch
    Flower Description:
    Green, insignificant flowers in April in terminal drooping cymes. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown for pollination to occur.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Gold/Yellow
    Green
    Pink
    Red/Burgundy
    Deciduous Leaf Fall Color:
    Gold/Yellow
    Red/Burgundy
    Leaf Margin:
    Lobed
    Hairs Present:
    No
    Leaf Width:
    1-3 inches
    Leaf Description:
    Lobed leaves green most of the year turn yellow to brick red in the fall.
  • Bark:
    Bark Color:
    Dark Brown
    Dark Gray
    Light Brown
    Light Gray
    Surface/Attachment:
    Fissured
    Smooth
    Bark Description:
    Smooth, brownish gray bark becomes fissured with age
  • Stem:
    Stem Color:
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    The stems are smooth and red in winter.
  • Landscape:
    Landscape Location:
    Slope/Bank
    Woodland
    Landscape Theme:
    Butterfly Garden
    Children's Garden
    Nighttime Garden
    Pollinator Garden
    Shade Garden
    Winter Garden
    Design Feature:
    Shade Tree
    Understory Tree
    Attracts:
    Butterflies
    Moths
    Pollinators
    Small Mammals
    Songbirds
    Resistance To Challenges:
    Diseases
    Erosion
    Insect Pests