Red Maple

'Leaf emergence'

Acer rubrum

Sapindaceae · broadleaf deciduous tree · introduced

Last updated

A fast-growing deciduous tree native to eastern North America from Canada to Texas, reaching 68 feet. One of the first maples to bloom, producing small red flowers (the source of the common name) before leaves emerge in late winter to early spring, giving the tree a reddish haze. Bark is smooth and light gray on young trees, becoming dark, rough, and furrowed with age. Leaves are relatively small for a maple, usually three-lobed with serrated margins. Fall color ranges from green-yellow to brilliant orange and red, often among the first trees to turn. Native habitat spans swamps, uplands, and occasionally dry hillsides and sand dunes.

Hardy to Zone 2a. Sun to part shade. Prefers moist, slightly acidic soils (pH 4.7 to 7.3) and tolerates wet soils, including rain garden placement. High water needs. Fast growth. Low maintenance. Develops pronounced surface roots that can lift pavement. Tolerates urban conditions and black walnut proximity. Five cultivars: 'Autumn Spire' (50 feet, male/seedless, deep red fall color, Zone 3), 'Bowhall' (very narrow, 15 feet wide, yellow-orange to red, Zone 4), 'October Glory' (PP2116, brilliant orange-red, rounded, 35 feet, Zone 4b), 'Red Sunset' (PP7803, consistent red, broadly pyramidal, 40 to 50 feet, Zone 4), and 'Redpointe' (PP16769, improved branching, 30 to 45 feet, Zone 5). Nineteen diseases and eleven pests documented.

Red maple is not native to our region but it performs well here (hardy zones 3a through 9b). It is one of the first trees to bloom in spring (March-April, as low as 28 GDD base 50) with red flowers before leaves, making it a useful phenological indicator. The tree tolerates wet soil and urban conditions better than most maples, which makes it viable for the poorly drained lowland sites where Japanese maple would struggle. Fall color is variable from seed-grown trees; select named cultivars like ‘October Glory' or 'Red Sunset’ for reliable color. The standard maple diseases (tar spot, powdery mildew, anthracnose) apply but are cosmetic. Cottony maple scale can be heavy some years. Red maple establishes well in rain gardens and low spots that other trees reject.

— Chris Welch, ISA Certified Arborist

Plant Profile

Size & Form

Height
40-70 ft, to 120 ft in southern…
Spread
30-50 ft
Growth Rate
Fast
Size at 20 yr
25-35 ft (fast-growing first 20-30 years, then slows; source: PFAF)
Lifespan
Moderate

Site Requirements

Light
Sun to Part Shade
Soil Drainage
Moist
Soil pH
4.7–7.3
Water
High
Drought Tolerance
Moderate to high
Hardiness
Zones 3a–9b

Ornamental Interest

Bloom Time
March to April
Fall Color
Orange, purple, red, yellow
Origin
Eastern North America, from Newfoundland to Florida

Field Observations

Red Maple new leaves
Red Maple: New leaves
April 13, 2026 · Issaquah
Red Maple first bloom
Red Maple: First bloom
March 14, 2026 · Issaquah
Red Maple fall color
Red Maple: Fall color
November 3, 2022 · Issaquah
Watch for this season

Active Conidial Spread

Root Colonization Period

Wood DecayHigh

Wound Infection Window

AphidHigh

Peak Population & Dispersal

+ 9 more — see full disease and pest lists below

Diseases: Regionally Documented (17)

Pests: Regionally Documented (13)

Phenological Calendar

As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Red Maple has passed 'leaf emergence' (1364 GDD₃₂).

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 2,673 'Leaf emergence'
Kent / Auburn 2,665 'Leaf emergence'
Seattle / UW 2,610 'Leaf emergence'
Olympia / Tumwater 2,570 'Leaf emergence'
Tacoma / Puyallup 2,535 'Leaf emergence'
Bellingham / Whatcom 2,533 'Leaf emergence'
Sequim / Rain Shadow 2,436 'Leaf emergence'
View full calendar (7 stages)
Stage GDD32 Typical Window
'Bud break' BBCH '07' 1242 ''
'Flower buds visible' BBCH '51' 1221 ''
'First bloom' BBCH '61' 'March to early April'
'Full bloom' BBCH '65' 'March to April'
'Leaf emergence' BBCH '11' NOW 1364 Observed ''
'Fruit maturity (samara shed)' BBCH '87' 'May to June'
'Fall color / leaf senescence' BBCH '93' 1228 Observed ''
Range: 294–512 GDD₃₂ (6yr)

Source: 'NPN citizen science observations (WA+OR), n=10, median. services.usanpn.org' About GDD₃₂ →

Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.

Cultivars (9)
'Autumn Flame' Autumn Flame®
Dense rounded spreading branches, 35 x 35 ft, male (seedless), medium green foliage, bright red fall color, one of the earliest to color
Hardy to USDA Zone 3b. Introduced c. 1964 by A. McGill & Sons nursery, Fairview, Oregon
'Autumn Spire'
Narrow upright form, 50 ft, deep purple-red to bright red fall color. Male only (seedless).
Hardy to USDA Zone 3
'Bowhall'
Very narrow, upright, 40 x 15 ft, female, medium green foliage, yellow-orange to reddish-orange fall color
Hardy to USDA Zone 4. Selected by Scanlon nursery of Ohio in 1946, named 1951. Named after the road where original tree was discovered near Cleveland.
'Karpick' Karpick®
Narrow oval shape, 40 x 20 ft, male (seedless), yellow to orange fall color
Hardy to USDA Zone 4. Introduced 1992 by Schichtel nursery, Orchard Park, NY. Named for Frank E. Karpick, city forester of Buffalo, NY.
'Northwood' Northwood®
Broadly oval to rounded, open form, 40 x 35 ft, male (seedless), medium to dark green foliage, reddish fall color
Hardy to USDA Zone 3, maybe the hardiest of the Red Maples. Discovered by Leon Snyder in northern Minnesota, introduced by Minnesota Landscape Arboretum in 1980.
'PNI 0268' October Glory®
Broadly oval to round, 40 x 35 ft, female, medium glossy green leaves with long red petioles, deep red to reddish-purple fall color, one of the last to color in fall
Hardy to USDA Zone 4b. Reportedly better adapted to mild winters and hot summers than other selections. Introduced c. 1961 by Princeton nursery, NJ.
'Franksred' Red Sunset®
Upright branching, oval shape, 45 x 35 ft, female, strongly 3-lobed dark glossy green leaves, brilliant orange-red to red fall color
Hardy to USDA Zone 4. Developed in the 1940s by J. Frank Schmidt, Jr. of J. Frank Schmidt & Sons nursery, Boring, Oregon, introduced 1966.
'Frank Jr.' Redpointe®
Broadly pyramidal, dominant central leader, fast growing, 45 x 30 ft, dark green leaves, brilliant red fall color
Hardy to USDA Zone 5. Developed by Frank Schmidt & Co. nursery, Boring, Oregon, introduced c. 2006.
'Somerset'
A. rubrum cultivar used in Phytophthora root rot research
Data Maturity
Structured Multiple sources. Expert review underway.