Bigleaf Maple.

At a glance

Care level

Easy

Plant type

Deciduous Tree

Light

Full sun to partial shade

Indoor light

bright-indirect

Water

Every 7 to 14 days

Mature size

Up to 30m (100ft) tall and 15m (50ft) wide

Growth rate

fast

Hardiness

USDA 7 to 10

Bloom time

Late spring

Care

This tree thrives in moist, well-drained soil and prefers a location with ample sunlight. While it's relatively low-maintenance, occasional pruning can help maintain its shape and remove any dead or damaged branches.

Watering

Water regularly, especially when young, keeping the soil consistently moist but not waterlogged.

Feeding

Fertilize once in early spring with a balanced fertilizer if growth seems slow.

Pruning

Prune in late winter to remove dead, damaged, or crossing branches and to shape the tree.

Repotting

Mature trees rarely need repotting; young trees can be repotted when root-bound.

Soil

Prefers moist, well-drained soil; adaptable

Soil pH

Slightly acidic to neutral (6.0-7.0)

Temperature

-23.3 to 32.2°C

Humidity

40 to 60%

Safety

People

The seeds contain compounds that can be mildly toxic if consumed in large quantities without proper preparation.

Children

Children may be tempted to eat the seeds, which should be avoided due to potential mild toxicity.

Contact allergens

No significant contact allergens are noted.

Airborne allergens

Pollen can be an allergen for sensitive individuals, especially during its spring bloom.

Edibility

While the seeds and young leaves are technically edible, preparation is necessary to remove bitterness and potential toxins.

How to identify it

• Very large maple leaves
• Yellow-green fragrant flower clusters
• Hairy, pendulous flower stalks
• Large, dense seed clusters
• Gray-brown, furrowed bark

Height

15 to 30m

Spread

7.5 to 15m

Leaves

green, deciduous

Flowers

yellow-green, 1 to 2cm

Fruit

brown, Autumn

Common problems

• Aphids — Small, pear-shaped insects that feed on plant sap, often clustering on new growth and causing distorted leaves.
• Verticillium Wilt — A soil-borne fungal disease that can cause wilting, yellowing, and death of branches, often appearing suddenly.
• Tar Spot — A fungal disease that causes distinctive black spots on the leaves, usually appearing later in the growing season.
• Root Rot — Fungal disease favored by poorly drained soils, leading to yellowing leaves, stunted growth, and eventual plant decline.

Growing it

Propagation

Seed, Cuttings

When to plant

Spring, Autumn

Planting shrubs and ferns that enjoy moist shade beneath its canopy can create a beautiful, naturalistic woodland garden.

Grows well with

• Douglas Fir — These trees often grow together in mixed forests, sharing similar habitat preferences.
• Western Hemlock — They are frequently found in the same moist, temperate forest ecosystems.
• Sword Fern — This common understory fern thrives in the shade and moist conditions provided by large maples.
• Red Alder — Both species are pioneer species that can colonize disturbed areas, especially near water sources.

Keep away from

• Drought Stress — Prolonged dry periods, especially when young, can severely weaken or kill the tree.
• Road Salt — Salt spray from roads can cause leaf scorch and damage to the bark.

Similar species

• Red Maple — While similar in its ornamental appeal and leaf shape, Red Maple is native to eastern North America and has smaller leaves.
• Vine Maple — This is another Pacific Northwest native maple, but it typically grows as a multi-stemmed shrub or small tree with smaller, deeply lobed leaves.

Science

Family

Sapindaceae

Genus

Acer

Order

Sapindales

Class

Magnoliopsida

Native range

Western North America, from British Columbia south to Southern California.

Conservation

Not of conservation concern.

It typically grows in moist forests, along streams, and in open woodlands, often dominating the understory or forming small stands.

Value to wildlife

nectar source, larval host plant, provides cover

Pollinators

bees, butterflies, moths

Uses

ornamental shade tree, timber, food (seeds/leaves, prepared)

Taxonomy resolved against GBIF.

Questions people ask

How big can Acer macrophyllum get?

It can reach heights of 50 to 100 feet, with a spread of up to 50 feet.

What kind of soil does it prefer?

It thrives in well-drained soils and can tolerate a range of soil types, from sandy to clay.

Is it suitable for small gardens?

Due to its large size, it's best suited for larger yards or open spaces where it has room to grow.

Does it have good fall color?

Yes, its fall color is typically a lovely golden yellow.

Where the name comes from

The common name 'Bigleaf Maple' refers to its impressively large leaves. The scientific name 'macrophyllum' also means 'large-leaved' in Greek.

Good to know

• It's the largest native maple species in North America.
• Indigenous peoples used the sap to make syrup or sugar.
• Its wood is used for furniture, flooring, and musical instruments.
• The large leaves can create significant shade.