There are about 130 species of maple trees (Acer) in the world, with different varieties found throughout U.S. Department of Agriculture plant hardiness zones 3 through 9. Each species has its own characteristics, including variances in leaf shape and color, bark, hardiness and overall tree form.
The bigleaf maple also referred to as Oregon maple has the largest leaves of any maple. These leaves are the largest of any maple species in North America, measuring up to 12 inches in diameter. They are deeply lobed, with 5 lobes but occasionally 3 lobed. The leaves are a glossy green in the summer and turn yellow to yellow-orange in the fall.
The Bigleaf Maple tree, scientifically known as Acer macrophyllum, is native to the Pacific Northwest region of North America. It is found in a range that extends from the southwestern corner of British Columbia to Vancouver Island (lat 33 to 51°N)., Canada, through western Washington and Oregon, and into northern and central California in the United States.
In California, its distribution extends from the coast to the western slopes of the Sierra Nevada mountains. The tree thrives in moist, well-drained soils and is commonly found in low to middle elevations in the coastal ranges and the northern Sierra Nevada mountains. It usually grows from near the Pacific Ocean to a maximum of 186 miles inland.
Bigleaf maple is commonly found in association with almost all other tree species in its range. The greatest abundance of bigleaf maple is in the foothills of the Cascade and Coast ranges. Its most common association are Douglas-fir, grand-fir, red alder, Sitka spruce, western redcedar, western hemlock, Pacific dogwood, and Pacific madrone.
Common shrub and herb associates include serviceberry, salal, red huckleberry, devil’s-club, Pacific rhododendron, thimbleberry, salmonberry, vine maple, and hazel. Herbaceous associates include maidenhair fern, western swordfern, ladyfern, red woodsorrel, false lily-of-the-valley, prince’s-pine, spreading sweetroot, and twinflower.
In May 2018 the oldest two Oregon maples in Europe, 175 years old, were removed from Trinity College Dublin (TCD), Ireland. The first had an interior which was beginning to rot, and it fell after inclement windy weather. The second, also infected, was cut down as the same fate was expected. Both were in the adjoining grassy area which was originally the cemetery of All Hallows and is now the Front Square of TCD.
Native Americans grew sprouts from the seeds for consumption, wove baskets from the inner bark, and used the leaves to cover food in cooking pits. They also carved the wood into dishes, utensils, and canoe paddles.
Characteristics of Big Leaf Maple (Acer macrophyllum)
- Its botanical name is Acer macrophyllum. The term “macrophyllum” is derived from the Greek words “makros,” meaning long or large, and “phyllon,” meaning leaf.
- It is a deciduous tree in nature, shedding its leaves in the fall and regrowing them in the spring.
- Big-Leaf Maple grows rapidly when young, more slowly as it ages.
- It is the largest maple species, capable of reaching heights of up to 100 feet.
- Hardy to USDA zones 7 through 11.
- Bigleaf maple begins bearing seed at about ten years of age
- Fast-growing, adding 24 inches (60 centimeters) or more per year in ideal conditions
- The leaves of the Bigleaf Maple are the largest of any maple species.
- Big leaf maple, is hermaphroditic, bearing both male and female flowers in each raceme. The flowers appear in early spring, before the leaves
- The tree produces a sugary sap, which can be used to make maple syrup.
- The root system of bigleaf maple is shallow and spreading on wet or shallow soils.
- It is an important food source for wildlife such as deer, elk, bears, birds and small mammals.
- Bigleaf maple is moderately long-lived; some individuals may reach 300 years of age.
- Their threats include: habitat loss due to development, logging and climate change.
- Like some other maples, bigleaf maple produces sap that can be boiled down to a mineral-rich and delicious maple syrup.
- Its fine-grained, pale brown wood is commercially valuable for making musical instruments and furniture veneer.
- Bigleaf maple is second to red alder among native hardwood species in abundance and in commercial importance in the Pacific Northwest.
Cultivars of Bigleaf Maple (Acer macrophyllum)
| Cultivar Name | Description |
|---|---|
| Acer macrophyllum ‘Mocha Rose’ | A smaller cultivar with a more compact form and leaves that emerge with a red-orange hue before turning green in summer and yellow in fall. |
| Acer macrophyllum ‘Seattle Sentinel’ | A columnar cultivar with a narrow, upright growth habit, making it suitable for smaller gardens or as a street tree. |
| Acer macrophyllum ‘Santiam Snow’ | A variegated cultivar with leaves that have creamy white margins and green centers, providing year-round interest. |
| Acer macrophyllum ‘Golden Riddle’ | A rare and unusual cultivar with golden yellow leaves that maintain their color throughout the growing season. |
| Acer macrophyllum ‘Pacific Sunset’ | A smaller cultivar with a more compact form and leaves that emerge with a red-orange hue before turning green in summer and yellow in fall. |
| Acer macrophyllum ‘Portland’ | A fast-growing cultivar with a dense, rounded crown and large, deeply lobed leaves. |
| Acer macrophyllum ‘Santiam’ | A large, cultivar species with a broad, spreading crown and large, lobed leaves. |
| Acer macrophyllum ‘Saratoga’ | A large, vigorous cultivar with a broad, spreading crown and large, lobed leaves. |
Pruning a big leaf maple
The best time to prune a big leaf maple is during the dormant season, which is typically late winter or early spring before the new growth begins. This timing minimizes sap loss and allows the tree to heal quickly.
Before you start pruning, take a step back and assess the tree’s overall shape and structure. Identify any dead, diseased, or damaged branches that need to be removed. Also, look for branches that are crossing or rubbing against each other, as these can cause wounds that may lead to infection.
Remove dead, diseased, or damaged branches: Start by removing any dead, diseased, or damaged branches. Cut these branches back to the point where they join a larger branch or the trunk. Make the cut just outside the branch collar, which is the slightly swollen area where the branch meets the trunk or larger branch. This collar contains chemicals that help the tree heal the wound.
Next, thin out the canopy by removing some of the smaller branches growing within the tree’s interior. This will increase air circulation and sunlight penetration, which can help reduce the risk of disease and promote healthy growth.
To maintain the tree’s natural shape, selectively prune branches that are growing out of proportion or detracting from the overall form. Make the cuts just above a healthy bud or lateral branch.
Suckers are small shoots that grow from the base of the tree, while water sprouts are fast-growing vertical branches that often originate from the trunk or main branches. Remove these unwanted growths by cutting them off as close to their point of origin as possible.
After pruning, clean up the area around the tree by removing all the pruned branches and debris. Dispose of any diseased or infested material to prevent the spread of disease or pests.
Uses of Bigleaf maple in the landscape
- The tree’s extensive root system helps to stabilize slopes and prevent soil erosion in areas with water runoff or steep inclines.
- Due to its size and adaptability, the Bigleaf maple can be used as a street tree, along urban streets and boulevards.
- The Bigleaf maple tree serves as a valuable habitat and food source for various wildlife species, including birds, squirrels, and small mammals.
- The tree’s striking, large leaves, fall color and attractive bark, make it good for use as an ornamental tree.
- With its large, broad canopy, the Bigleaf maple works well as a shade tree especially in parks, gardens, and other outdoor spaces.
What Shrubs and Trees Go Well With Bigleaf Maple (Acer macrophyllum)?
- Vine Maple (Acer circinatum)
- Red Alder (Alnus rubra)
- Western Red Cedar (Thuja plicata)
- Pacific Rhododendron (Rhododendron macrophyllum)
- Sword Fern (Polystichum munitum)
- Salal (Gaultheria shallon)
- Oregon Grape (Mahonia aquifolium)
- Douglas Fir (Pseudotsuga menziesii)