Acer rubrum 'Autumn Red'

Canadian Maple — Autumn Red

Botanical Name: Acer rubrum 'Autumn Red'
Family: Sapindaceae
Origin: Eastern North America
Plant Type: Deciduous feature and shade tree

Overview

Acer rubrum 'Autumn Red' is a large, vigorous deciduous shade tree prized across Australian gardens and parklands for its spectacular seasonal transformation — a dense green summer canopy giving way each autumn to one of the boldest scarlet-to-crimson displays available outside of a Japanese garden. Notably, this cultivar holds its green colour later into the season than many comparable red maples before igniting into brilliant orange-red and deep lipstick crimson. A straight central leader with ascending branches matures into a broad oval-to-rounded crown delivering substantial summer shade while providing year-round structural beauty.

Key Features

• Mature Size: 10–13 m H × 8–10 m W
• Growth Rate: Fast; 45–70 cm per year; strong upright growth in youth with ascending branches, broadening progressively to a full oval-rounded canopy at maturity
• Foliage: Deciduous; deep green, 3–5-lobed maple leaves in spring and summer; foliage holds green longer than most red maple cultivars before transitioning to brilliant scarlet and deep lipstick crimson in autumn — colour intensity is best with cool autumn nights
• Flowers: Dense clusters of small, showy crimson flowers emerge along bare branches in late winter to early spring (August–September in SA), well ahead of new foliage; non-fragrant
• Seasonal Interest: Late-winter crimson flowers on bare stems; fresh green spring foliage; dense cooling shade canopy in summer; incandescent scarlet-crimson autumn display; clean architectural winter silhouette
• Wildlife Value: Late-winter flowers provide an early nectar source for bees and native insects; paired winged samaras attract seed-eating birds; broad canopy provides nesting and sheltering habitat through spring and summer
• Tolerance: Frost hardy (handles heavy and repeated frost without damage); adapts to moist and seasonally wet soils; tolerates part shade; suits cool to temperate climates
• Planting Density: Feature or specimen planting — allow a minimum 8 m clearance from buildings, utilities, and neighbouring trees; avenue or park row planting — space trees 6–8 m apart centre-to-centre for a seasonal colour corridor
• Pet Friendly: Non-toxic to dogs and cats. Important — wilted fallen leaves are highly toxic to horses and can cause serious illness; do not plant in or directly adjacent to horse paddocks or equine grazing areas

Where It Works Best

• Sunlight: Full sun preferred for densest canopy and richest autumn colour; tolerates part shade — morning sun with afternoon protection suits hotter SA locations well
• Soil: Prefers deep, moist, humus-rich loam; tolerates clay and seasonally wet ground provided drainage is reasonable; avoid shallow sandy or highly alkaline soils
• Water Needs: Establishment (first 2 years): water 2–3 times per week during warm months, reducing to once per week in cooler months. Established: moderate — water weekly throughout summer, fortnightly in autumn and spring, minimal in winter; deep watering during summer heat events is essential for colour performance
• Maintenance: Low once established; apply a generous mulch layer annually to retain moisture and keep roots cool; prune only to remove dead, crossing, or structurally weak branches — carry out in late winter while fully dormant
• Lifespan: 80–150+ years
• Climate Zones: Best in the Adelaide Hills, Mt Lofty Ranges, Barossa Valley, and Clare Valley where cold autumn nights intensify colour; performs well with supplemental irrigation across the Adelaide Plains and northern suburbs; autumn colour can be muted in warm coastal zones; not suited to hot arid regions without reliable irrigation
• Soil pH: Slightly acid to neutral preferred (pH 5.5–7.0); avoid strongly alkaline soils — high pH causes interveinal chlorosis; amend with sulfur and organic matter in lime-rich SA soils before planting

Landscape & Design Ideas

• Plant as a solitary specimen on a large lawn or open parkland where the autumn transformation can be appreciated from every angle — underplant with low deciduous perennials or spring bulbs that follow the same seasonal rhythm
• Use in formal double-row avenue plantings at 6–8 m spacing to create a dramatic seasonal colour corridor in parks, schools, wineries, and estate driveways
• Combine with complementary deciduous trees — ornamental pears, golden elms, and liquidambars — in larger garden or council plantings for a multi-hue autumn palette spanning gold through to deep crimson

Why You Will Love It

Few trees earn their space the way 'Autumn Red' does — four seasons of genuine value: bold crimson flowers on bare winter stems, a lush green canopy that outperforms most shade trees through summer, and then, when the season finally turns, an incandescent blaze of scarlet and crimson that stops people in their tracks. Plant it once and it will still be turning heads long after you are gone.