Sugar Maple

Full bloom / pollen release

Acer saccharum

Sapindaceae · broadleaf deciduous tree · native

Last updated May 26, 2026

The iconic deciduous tree of northeastern North American hardwood forests, slow-growing and long-lived, reaching 100 feet with a broadly pyramidal to rounded crown and a 39-foot spread. Famous for maple syrup production and brilliant fall color. Leaves are opposite, with deep, rounded lobes. Flowers are small, greenish-yellow, without petals, on thin pendulous stalks appearing before leaves in April. Bark becomes deeply furrowed with long, irregular thick plates. Fall color is brilliant yellow, burnt orange, and red, highly variable between individuals. Native from the Maritime provinces south through Ontario and Quebec to Georgia, Mississippi, and Texas.

Hardy to Zone 2a. Part shade. Slow growth. Adaptable drainage; pH 3.7 to 7.9. Prefers deep, rich, well-drained soils. Does best in regions with cool winters, moderate summers, and adequate spring moisture; struggles where summers are hot and dry. Medium maintenance. Tolerates heavy shade. Edibility rating 4 (syrup). Seven cultivars: 'Apollo' (columnar, 30 feet, Zone 4), 'Bonfire' (orange-red fall, 50 feet), 'John Pair' (dense, red fall, 25 to 30 feet, Zone 5), 'Legacy' (30 feet, Zone 4), 'Newton Sentry' (extremely upright columnar), 'Sweet Shadow' (deeply cut lobes, orange-red), and 'Temples Upright' (strong central leader, 50 to 60 feet). Nineteen diseases and eleven pests documented.

Established specimens occur in residential landscapes but are uncommon relative to other maples. Dry summers (July–September) cause visible leaf scorch on unirrigated trees. Fall color is typically muted compared to the species' display in the northeastern U.S., likely due to the gradual maritime temperature decline and lower autumn light intensity. Road salt is not a factor in this region; soil compaction and urban air quality are the primary abiotic stressors observed in local street plantings. New plantings frequently struggle to establish, particularly on the heavier soils common across the region; poor drainage in clay and clay-loam sites appears to compound the summer drought stress and slow root development.

— Chris Welch, ISA Certified Arborist

Plant Profile

Size & Form

Height

80–115 ft

Spread

40–50 ft

Growth Rate

Slow

Size at 20 yr

~20 ft

Lifespan

300–400 years

Site Requirements

Light

Full Sun to Part Shade

Soil Drainage

Well Drained

Soil pH

3.7–7.3 (optimum 5.5–7.3)

Water

Moderate

Drought Tolerance

Low

Hardiness

Zones 3a–8b

Ornamental Interest

Bloom Time

late March to mid-May (varies by latitude)

Fall Color

Yellow, orange, red

Origin

Pacific Northwest native

Powdery MildewHigh

Active Conidial Spread

Verticillium WiltHigh

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)

Verticillium dahliae Verticillium Wilt Rhytisma punctatum Tar Spots Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew Phyllosticta spp. Phyllosticta Leaf Spot Neonectria ditissima Nectria Canker Multiple possible causes (see Disease Cycle section) Fasciation Bacterial Leaf Spot and Dieback Discula destructiva (dogwood), Kabatiella and Discula spp... Anthracnose Kretzschmaria deusta Brittle Decay Multiple Basidiomycete fungi cause wood decay in trees Wood Decay Armillaria spp. — primarily A Armillaria Root Rot Bigleaf Maple Decline (Bigleaf Maple Dieback) Phytophthora spp. (P Bleeding Canker Taphrina spp. Leaf Blister Symptom category — not a single disease Leaf Spot Phytophthora spp. (P Phytophthora Root Rot Cryptostroma corticale Sooty Bark Disease

Pests: Regionally Documented (13)

Vasates quadripedes Maple Bladdergall Mite Pulvinaria innumerabilis Cottony maple scale Aphidoidea Aphid Boisea rubrolineata Western boxelder bug Prionoxystus robiniae Carpenterworm Megachile spp. Leafcutting bee Proteoteras aesculana Maple tip moth (Maple twig borer) Lepidosaphes ulmi Oystershell scale Otiorhynchus spp. Root weevil Edwardsiana rosae Rose leafhopper Leucoma salicis Satin moth Frankliniella occidentalis Western flower thrips Proteoteras moffatiana Maple shoot moth

Phenological Calendar

As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Sugar Maple has passed full bloom / pollen release (1974 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	Full bloom / pollen release	—	—
Kent / Auburn	2,665	Full bloom / pollen release	—	—
Seattle / UW	2,610	Full bloom / pollen release	—	—
Olympia / Tumwater	2,570	Full bloom / pollen release	—	—
Tacoma / Puyallup	2,535	Full bloom / pollen release	—	—
Bellingham / Whatcom	2,533	Full bloom / pollen release	—	—
Sequim / Rain Shadow	2,436	Full bloom / pollen release	—	—

View full calendar (8 stages)

Stage	GDD₃₂	Typical Window	What to Look For
Bud swell BBCH 01	— Observed	late February to early April (latitude-dependent)	Buds visibly swelling; flower buds begin to swell at or slightly before leaf buds
Leaf emergence BBCH 11	1079 Observed	early to mid-April in Puget Sound; observed April 8 in Seattle (2021)	First leaves unfolding; in native range leaves typically emerge after flowers, but Seattle observation showed leaves first
First bloom BBCH 61	1567 Observed	late April to mid-May in Puget Sound; observed May 2 in Seattle (2021)	Greenish-yellow apetalous flowers on long pendulous pedicels
● Full bloom / pollen release BBCH 65 NOW	1974 Observed	1–3 weeks after first bloom; observed May 20 in Seattle (2021)	Peak flowering; pollen release from anthers
Fruit set BBCH 71	— Observed	May to June	Paired samaras forming; fruit ripens in about 16 weeks from flowering
Fruit maturity BBCH 89	— Observed	September to October	Samaras turn yellowish green; begin falling about 2 weeks after ripening, just before leaf fall
Leaf senescence BBCH 93	— Observed	October to November	Leaves turn brilliant yellow, orange, and red; one of the most spectacular fall color displays of any North American tree
Dormancy BBCH 97	— Observed	November to February	Leaves fully dropped; requires ~2,500 hours continuous chilling to break dormancy in northern races

Sources: NPN observation (species_id 61, 2021, n=1) ; USDA Silvics of North America (Godman et al.) 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 (11)

'Apollo'

Narrow, columnar tree, densely branched and compact; 25-30 ft tall; fall color yellow-orange and red

Hardy to USDA Zone 4. Good for narrow spaces.

'Bonfire'

Medium green leaves in summer; fall color yellow, orange, orange-red, and red; mature height ~50 ft

'John Pair'

Medium-size tree (25-30 ft), dense habit; glossy green leaves; red color in early fall

Hardy to USDA Zone 5. Selected for heat tolerance.

'Legacy'

Oval form, 50 ft tall x 35 ft wide; leaves glossy green, very thick, leathery, resistant to leaf tatter and drought damage; red-orange to red fall color

Hardy to USDA Zone 4. PP4979 (1983); discovered 1967 at Duncan Nursery, Champaign, IL. One of the most widely recommended cultivars.

'Newton Sentry'

Extremely upright, columnar form; major branches with many short stubby branchlets; distinctive sentinel habit

Very narrow form useful for tight spaces or formal plantings.

'Sweet Shadow'

Leaves slightly drooping, deeply lobed with each lobe further cut (lacinate); orange-red fall color

Distinctive cutleaf foliage texture.

'Temple's Upright'

Strong central leader; lateral branches ascending gradually; 50-60 ft tall; fall color orange-yellow to red. Also sold as 'Monumentale'.

Notable cold hardiness.

'Green Mountain'

Upright, oval form; 50-60 ft tall x 45-50 ft wide; rapid growth for a sugar maple; dark green leathery foliage; thick leaves resistant to leaf scorch; orange and golden yellow fall color

One of the most popular cultivars. Notably tolerant of heat and dry conditions. Best choice where summer stress is a concern. PP2339, Princeton Nurseries; from an outstanding tree found in Vermont by William Flemer III.

'Commemoration'

Oval to rounded form; 50 ft tall x 35 ft wide; faster growth rate than species; thick green leaves resistant to leaf tatter; orange to orange-red fall color

'Fall Fiesta'

Oval to rounded form; 60-70 ft tall x 40-50 ft wide; leathery glossy green leaves; faster growing than other sugar maples; yellow, orange, and red fall color

PP11119 (1999), Bailey Nurseries ('Bailsta'). More heat, wind, and drought tolerant than the species.

'Crescendo'

Broadly oval; 30-40 ft tall x 30 ft wide; dark green leaves; orange-red fall color

Tolerant to heat and drought once established. Introduced by The Morton Arboretum through Chicagoland Grows ('Morton').

Data Maturity

Structured Multiple sources. Expert review underway.

Plant Origin

Native Range

Eastern North America: Maritime provinces through southern Ontario and Quebec, throughout New England, New York, Pennsylvania, the middle Atlantic States, south through the Appalachians to Georgia and Tennessee, west through Missouri, Iowa, and eastern Minnesota. NOT native to the Pacific Northwest.

Climate Type

Continental

Puget Sound Fit

Marginal

Sugar maple evolved under cold continental winters and warm, humid summers with consistent rainfall. Puget Sound's mild wet winters and dry summers invert this pattern, making supplemental summer moisture essential and limiting the fall color display the species is known for.

Native range

Puget Sound

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