Bigleaf Maple Tree Seeds | Oregon Maple | (Acer macrophyllum)

The biggest maple leaves in the world. The fastest maple in the Pacific Northwest.

Acer macrophyllum, the Bigleaf Maple, is the dominant large deciduous tree of the Pacific Coast forests, the only maple native to western North America that grows into a large canopy tree, and the species with the largest leaves of any maple on the planet. The leaves can reach 12 inches across, covering the forest floor in yellow-gold in October in one of the most spectacular fall displays of any western native tree. It grows faster than any other native maple in its range, establishes readily on disturbed sites and forest edges, and develops into a massive, wide-spreading canopy tree that becomes the structural backbone of Pacific Coast riparian and mixed forests. It is also the only commercial maple syrup source in western North America, with Indigenous peoples of the Pacific Northwest harvesting the sap for centuries. If you are looking to buy Bigleaf Maple seeds or grow this Pacific Coast native from seed, this is the maple that defines the temperate rainforest of western North America.

• The largest maple leaves of any maple species on Earth, reaching 12 inches across
• The only large native deciduous tree of the Pacific Coast forests, dominant in mixed and riparian woodland
• Brilliant yellow-gold fall color from the massive leaves, spectacular in quantity
• Faster-growing than any other native maple in the Pacific Northwest
• The only commercially viable maple syrup source in western North America

Things you probably did not know about the Bigleaf Maple

The leaves are so large they become nursery beds for entire ecosystems. In the wet Pacific Coast forests where Bigleaf Maple dominates, the large fallen leaves accumulate in deep piles that do not dry out under the constant rain and fog. These moist leaf piles become germination beds for mosses, ferns, and other understory plants, and feeding grounds for the salamanders, beetles, and invertebrates that break them down. The sheer size of each leaf creates a microhabitat that smaller-leaved trees simply cannot.

The moss gardens that grow on the branches are among the richest in temperate North America. In the oldest Bigleaf Maple groves of the Olympic Peninsula and Oregon Coast Range, the living moss gardens growing on the horizontal branches of mature trees can be two feet deep and support hundreds of invertebrate species, salamanders, and plants that live their entire lives without touching the ground. Studies of old Bigleaf Maple groves document these branch moss gardens as distinct ecosystems with their own species composition and food webs.

Indigenous peoples of the Pacific Northwest used every part of the tree. The wood was used for tools, canoe paddles, and furniture. The inner bark was eaten as a vegetable when young and sweet in spring. The sap was tapped and boiled for syrup and sugar. The leaves were used to line berry-drying racks and food storage pits. The bark was used medicinally for coughs and skin conditions. Few trees contributed more to the daily material culture of the Pacific Northwest peoples.

The winged seeds are among the largest of any maple. Bigleaf Maple samaras, the paired winged seeds, are large and heavy relative to most maples, requiring a stronger wind or a greater height to achieve effective dispersal. They spin on descent as all maple seeds do, but the larger wing area creates a more dramatic autorotation that is visible from a greater distance than the smaller-seeded eastern maples.

Growing Details

• Botanical Name: Acer macrophyllum
• Stratification: Required, 60 to 90 days cold stratification
• USDA Zones: 6 to 9, best performance in Pacific Coast climates with cool, moist summers
• Soil: Moist, well-drained, slightly acidic, rich in organic matter
• Light: Full sun to partial shade
• Height: 50 to 100 feet
• Spread: 50 to 75 feet
• Growth Rate: Fast in suitable climates, 2 to 3 feet per year

Plant it in the Pacific Northwest or a comparable cool, moist climate and give it room. In the right conditions it becomes the tree that defines the entire landscape it grows in.