Bigleaf maple

Category: Hardwood
Region: Coast
Title: Bigleaf maple (Acer macrophyllum)

Photo credit: Kristin Charleton, Sundew Media

The largest maple in Canada, the bigleaf maple, grows only in the southwest corner of British Columbia (B.C.). It yields attractive wood that can be used for higher-value, appearance-grade products. Bigleaf maple is the largest maple tree in Canada and can reach 36 metres in height.

Where it grows

Bigleaf maple is a deciduous broadleaf tree that grows exclusively at low and mid elevations in the southwest corner of B.C. It is frequently found in clumps of three to five, all originating from a single stump. The species is moderately shade tolerant and commonly occurs in mixed groups of softwood and hardwood species such as red alder, black cottonwood, Douglas-fir, western red cedar and western hemlock. Bigleaf maple produces abundant seeds so its regeneration capacity is excellent even though the seeds are an important source of food for small mammals.

Big leaf maple species distribution map

Identifiable characteristics

Bigleaf maple, also known as Pacific Coast maple or western maple, is the largest maple tree in Canada, reaching 36 metres in height on good sites. In the forest, it develops a narrow crown that is supported by a stem free of branches for half its length. In the open, it has a broad crown supported by a few large spreading limbs. The bark is greyish-brown and shallowly grooved when the tree is older. The species lives an average of 200 years, with some up to 300 years.

The leaves are the largest of any maple in Canada, measuring 15 to 30 centimetres across. They are deeply five-lobed and have a few blunt, wavy teeth. They are shiny dark green on top and paler underneath and turn yellow in the fall. Small greenish-yellow flowers, about three millimetres across, appear in clusters at the ends of twigs in the spring. The fruit consists of two winged seeds joined at the base, which are three to six centimetres long.

Did you know?

Grain patterns are unsurpassed in some bigleaf maple trees. Occasionally, pieces have highly figured, wavy grain—these include bird’s eye, fiddle-back, blister and curly maple.

Photo credit: Kristin Charleton, Sundew Media

Daytime closeup image of Bigleaf Maple (Acer macrophyllum) leaf

Common uses and applications

Bigleaf maple wood is attractive, as well as hard and heavy, so it is used for higher-value, appearance-grade products such as flooring, cabinetry and furniture, as well as turnings, musical instruments and interior millwork. It is also used for panelling, veneer and plywood.

Coastal Indigenous Peoples consider it an excellent fuel. They also use the wood to carve utensils, tools and toys, including spindle whorls and canoe paddles. They use the bark to weave ropes and baskets and spread the leaves over and under food in steam pits and picking baskets.

Hand crafted wooden bowl made from Bigleaf Maple (Acer macrophyllum)

Commercial properties

Bigleaf maple is moderately heavy, hard and of medium strength. It is well known for its working properties. The wood dries without difficulty, but rather slowly. It is relatively easy to work, with good machining qualities. It turns, planes and shapes well and can be sanded to a smooth finish. The wood glues easily, has moderate nail and screw holding ability, and takes a good finish. The wood grain is straight or sometimes curly or wavy. It has medium to occasionally coarse grain and even texture.

UBC Forest Sciences Centre | Photo credit: Don Erhardt

Interior upward daytime view of multi storey wood clad atrium used as example of constructing with bigleaf maple (Acer macrophyllum)

Commercial availability

Bigleaf maple is moderately available and comes in appearance and millworking grades including Select and better, #1 shop and frame grade, produced according to National Hardwood Lumber Association rules.  The lumber is dried according to end use and customer specifications. Kiln drying inhibits natural staining of the wood, improves its strength and stiffness, enhances its appearance, and increases its resistance to decay and insect attacks.

Photo credit: Michael Bednar

Several smooth finished bigleaf maple (Acer macrophyllum) dimensional lumber boards shown as examples

Bigleaf maple – physical properties

Density (kg/m3)Green466
Air dry507
Specific gravity (12% m.c.)Standard0.47
Hardness (N)Side4110
MOE (Mpa)Green8960
Air dry11400
MOR (Mpa)Green55.9
Air dry91.0
Compression parallel (Mpa)Air dry42.2
Compression perpendicular (Mpa)Air dry5.72
Shear (Mpa)Air dry12.17
Cleavage (N/mm width)Air dry86.7
OD = oven dry
air = air dry 12%
Radial (OD)4.1%
Tangential (OD)7.6%
Volumetric (OD)12.1%
Volumetric (air)8.2%
Tang / rad ratio1.9

Bigleaf maple – visual properties

HeartwoodUsually light reddish-brown, but sometimes darker.
SapwoodWhite with a slight reddish-brown tinge. Wider than that of hard maples.
Heartwood / sapwood contrastLight-coloured heartwood and little contrast between heartwood and sapwood.
Latewood / earlywood contrastThe annual growth rings are indistinct as it is a diffuse-porous wood.
The wood has straight or sometimes curly or wavy grain, medium to occasionally coarse grain, and has an even texture.
Plainsawn lumber or rotary-cut veneer: faint growth ring, occasionally birdseye, curly, and wavy.
Quartersawn lumber or quarter-sliced veneer: occasionally curly and wavy.
Other: Occasionally pieces have highly figured, wavy grain. Figured forms of maple include bird’s eye, fiddle-back, blister and curly maple.
Wood often figured around knots.

Bigleaf maple – working properties

PlaningGood planing qualityA cutting angle of 20˚ assists the finishing operation when curly grain or other irregular grain is present.
TurningGood surface qualityOne of the most desirable B.C. species for turning.
SawingModerately easy to work with toolsMachines with less difficulty than hard maple in all operations.
BoringModerateMedium boring quality with brad point bits and poor quality with single twist bits.
Nail retention N/A
GluingGood to moderateBonds well with a fairly wide range of adhesives under a moderately wide range of bonding conditions.
StainingEasyGood to excellent stainability especially with light colours. Recommend light stain or clear finish followed by nitrocellulose/alkyd clear, sealer and finish.
PaintingAverage to good paint holding ability
LacqueringGoodMultiple coats of clear or a clear coat with a high build is recommended.
WaxingGoodExcellent results with clear finish. Performed well in the tape test (i.e. small flakes of the coating were detached at intersections of cuts) and in the pull-off test (i.e. average strength of 35 kg/cm2).
Ease of dryingModerately easyDries without undue difficulty, but rather slowly.
Natural decay resistanceNon-durable Should not be used under high decay hazard conditions.

Data for these property tables has been compiled by FPInnovations from internal and external scientific sources.
FPInnovations is a not-for-profit technical research institute serving the Canadian forest sector.