Acer macrophyllum

Common Name: bigleaf maple 
Type: Tree
Family: Sapindaceae
Native Range: British Columbia, California, Oregon, Washington
Zone: 6 to 7
Height: 40.00 to 75.00 feet
Spread: 40.00 to 75.00 feet
Bloom Time: April to May
Bloom Description: Greenish-yellow
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Shade Tree
Flower: Insignificant
Leaf: Good Fall

Culture

Easily grown in moist, slightly acidic, well-drained soils in full sun to part shade. Prefers moist, well-drained soils in cool summer temperatures reminiscent of those typically found in its native environment in the Pacific Northwest, but tolerates a variety of soil conditions ranging from moist to somewhat dry. Does not always perform well in the hot and humid summer conditions found in the southeastern U.S. where it is not recommended for planting south of USDA Zone 7.

Noteworthy Characteristics

Acer macrophyllum, commonly called bigleaf maple or Oregon maple, is a medium to large, deciduous tree with an oval to broad-rounded crown that typically grows to 40-75’ tall, but occasionally soars to 100’ tall. Overall, it is considered to be the most massive of the various species of maple found in North America. Gray to reddish-brown bark on mature trees is deeply furrowed. It is native to moist to dry sites from British Columbia to southern California, most commonly being found in moist woods and along streams in the lower elevations of the coastal ranges and northern Sierra Nevada mountains. This tree is rarely found growing more than 200 miles east of the Pacific Ocean. Trees in moist forested areas in western parts of the Pacific Northwest are often covered with mosses, lichens and ferns.

Deeply 5-lobed (occasionally 3-lobed) leaves (to 8-12” long and wide) emerge with burgundy tones in spring, mature to glossy medium to deep green, and finally turn yellow to yellow-orange in fall. Leaves found on this tree are the largest found on any species of maple, hence the common name of big leaf maple. Leaf stalks contain a milky sap. Fragrant greenish-yellow flowers (each to 1/3” across) bloom in April-May in 4-8” long pendant, cylindrical, chain-like clusters (racemes), with each cluster having up to 175 tiny flowers. Flowers bloom as the new burgundy-tinted leaves are developing, providing an often attractive color contrast. Flowers give way to two-winged samaras (each to 1 1/2” long) with wings spreading to 60 degrees. Samaras mature by autumn.

Genus name is the Latin name for a maple tree.

Specific epithet comes from the Greek words macro meaning large and phyllon meaning leaf in obvious reference to the huge leaves found on this tree.

Problems

No serious insect or disease problems. Powdery mildew and verticillium wilt can pose problems in some areas. Shallow spreading roots can crack sidewalks and driveways.

Garden Uses

Excellent shade tree for large landscapes and parks. Wood is commercially used for lumber and to make furniture, veneer, cabinets, paneling and floors. Saplings make excellent browse for deer and elk. Seeds are eaten by chipmunks, squirrels, mice and some birds. Sap may be used to make maple syrup, however in order to produce a given volume of syrup, a much larger amount of sap must be taken from this tree than from Acer saccharum (the sugar maple of Eastern North America) which has a much larger concentration of sugar in its sap.