Adirondack Crabapple

Full bloom

Malus 'Adirondack'

Rosaceae · broadleaf deciduous tree · introduced

Last updated

Malus 'Adirondack' (Rosaceae) is a deciduous ornamental crabapple cultivar noted for its narrow, upright habit and heavy spring bloom. White flowers open from red buds, and small persistent fruit provides winter interest and wildlife food.

This cultivar performs in full sun on well-drained soil. Bloom begins around 260 GDD (base 50 F) with full bloom near 379 GDD. Disease resistance is a key selection trait in modern crabapple breeding. Like all Malus, it benefits from good air circulation to reduce foliar disease pressure.

Among the strongest crabapple performers for the Puget Sound region. The narrow vase-shaped habit (10-12 ft spread on an 18-20 ft tree) fits between house and sidewalk without pruning, making ‘Adirondack’ a viable specimen for small residential yards and a useful street tree where overhead lines or property lines constrain canopy spread. Excellent resistance across all four major crabapple diseases is independently corroborated by the J. Frank Schmidt evaluation chart and the Morton Arboretum crabapple performance ratings. Apple scab pressure in maritime PNW is high in most years due to cool wet springs, so disease resistance is a non-negotiable trait for new crabapple installations here. As one of the latest-blooming cultivars in the recommended set, ‘Adirondack’ is useful for extending the regional pollination window for home-orchard fruiting apples — it overlaps with mid- and late-blooming apple cultivars (Gala, Honeycrisp, Fuji) that need cross-pollination. Fruit persistence into early winter provides forage for overwintering thrushes, cedar waxwings, and robins; the small 0.5-inch fruit size minimizes the sidewalk-mess problem associated with larger-fruited crabapples like ‘Indian Magic’. Selected as a Great Plant Picks recommendation, which is the regional plant-evaluation program covering British Columbia, Washington, and Oregon — the GPP endorsement is the closest equivalent to a regional trial result for ornamentals.

— Chris Welch, ISA Certified Arborist

Plant Profile

Size & Form

Height
18-20 ft
Spread
10-12 ft
Growth Rate
Slow (reaches 18 ft over ~20 years)
Size at 20 yr
18-20 ft
Lifespan
50-80 years typical for ornamental crabapples in…

Site Requirements

Light
Full sun (best flower production); tolerates light afternoon shade with reduced flowering
Soil Drainage
Well drained; tolerates a wide range of soil textures provided drainage is adequate
Soil pH
5.5-7.5 (slightly acidic to neutral); tolerates mildly alkaline conditions but optimum is moderately acidic per general Malus genus tolerances
Water
Moderate
Drought Tolerance
Moderate; established trees tolerate seasonal drought typical of pnw summers but benefit from supplemental irrigation in extreme dry years
Hardiness
Zones 4a–8b

Ornamental Interest

Bloom Time
May to early June (Puget Sound); among the latest-blooming crabapple cultivars, useful for extending pollination of fruiting apples
Fall Color
Insignificant (yellowish-bronze; not a notable feature)
Origin
Cultivar from open-pollinated seedling of Malus halliana
Watch for this season

Bloom Infection Window

Active Conidial Spread

First Flight

Diseases: Regionally Documented (3)

Diseases: Other Associations (1)

Pests: Regionally Documented (3)

Phenological Calendar

As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Adirondack Crabapple has passed full bloom (1706 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
Kent / Auburn 2,665 Full bloom
Seattle / UW 2,610 Full bloom
Olympia / Tumwater 2,570 Full bloom
Tacoma / Puyallup 2,535 Full bloom
Bellingham / Whatcom 2,533 Full bloom
Sequim / Rain Shadow 2,436 Full bloom
View full calendar (2 stages)
Stage GDD32 Typical Window
Beginning of flowering BBCH 61 1170 Late April to early May (Puget Sound)
Full bloom BBCH 65 NOW 1706 Early to mid-May (Puget Sound); among the latest-blooming crabapples
Range: 728–874 GDD₃₂ (6yr)

Source: UMD phenology catalog (UMD: extension.umd.edu) 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.

Data Maturity
Structured Multiple sources. Expert review underway.