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Malus 'Adirondack'
Adirondack Crabapple
Cultivar developed at the U.S. National Arboretum; parent species {M. halliana} native to China and Japan
Overview
Malus 'Adirondack' is a small deciduous tree reaching 15–20 feet (4.5–6 m) tall and 8–12 feet (2.4–3.6 m) wide, with a strongly columnar to narrowly vase-shaped crown — a spread-to-height ratio of roughly 0.5 to 0.6 that holds the canopy upright and narrow as the tree matures. Flowers are 1.5–2 inches (4–5 cm) across, white, opening from red to dark pink buds in dense clusters of 5–8 along the branches in April–May; the red bud color and the white corolla coexist on the same cluster for 3–5 days during early bloom, producing a bicolor effect visible from 20–30 feet (6–9 m) away. Leaves are alternate, ovate to elliptic, 2–4 inches (5–10 cm) long, dark green at maturity with dark reddish-purple new growth that holds the coloration for 2–3 weeks after budbreak. Fruit is small at 0.4–0.5 inch (10–13 mm), orange-red, borne in clusters of 3–6, and persists through winter into early spring. The cultivar carries field-documented resistance to apple scab (Venturia inaequalis), fire blight (Erwinia amylovora), cedar-apple rust (Gymnosporangium juniperi-virginianae), and powdery mildew — the four main crabapple diseases. Growth rate is moderate at 12–18 inches (30–45 cm) per year, reaching mature size in 10 years. Hardy to USDA zone 4. The cultivar was developed at the U.S. National Arboretum in Washington, D.C., from open-pollinated M. halliana seed and released in 1987. Not known to be toxic to pets or humans.
Native Range
Malus 'Adirondack' is a cultivar developed at the U.S. National Arboretum in Washington, D.C., from open-pollinated seed of M. halliana (a species native to China and Japan), and released to cultivation in 1987.Suggested Uses
Used as a specimen tree, narrow-site street tree, or in a planting strip at 8–10 foot (2.4–3 m) spacing. The 8–12 foot (2.4–3.6 m) mature crown width fits sidewalk planting strips, narrow front-yard beds, and lots where broader crabapples at 15–25 feet (4.5–7.5 m) wide exceed the available space. Persistent orange-red fruit carries winter visual interest from October through March and feeds birds through winter. The narrow crown reduces spring-bloom visual mass relative to wider-spreading crabapples; the cultivar does not grow well in shade, waterlogged soils, or compacted planting holes with poor drainage.How to Identify
Appearance
Size & Dimensions
Height15' - 20'
Width/Spread8' - 12'
Reaches mature size in approximately 10 years
Bloom Information
White flowers 1.5–2 inches (4–5 cm) across open from red to dark pink buds in dense clusters of 5–8 along the branches from mid-April through early May over a 2–3 week window. During the first 3–5 days of bloom, unopened red buds coexist with opened white corollas on the same cluster, producing a bicolor visual effect. Fragrance is light. Fruit 0.4–0.5 inch (10–13 mm) across ripens to orange-red in September and persists on the branches through winter into March.Detailed Descriptions
Flower Description
White flowers 1.5-2 inches across opening from red to dark pink buds; in dense clusters of 5-8; bicolor effect during early bloom; April-MayFoliage Description
Dark green; dark reddish-purple new growth (2-3 weeks after budbreak); alternate ovate to elliptic 2-4 inches longGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow in full sun with 6 or more hours of direct light in well-drained loam, clay, or silt at pH 5.5–7.5. Full sun is required for flower bud formation and for the disease-resistance traits to perform; partial shade reduces both bloom density and leaf health. Water deeply once per week during the first two growing seasons, then reduce to supplemental irrigation during extended drought. Apply a balanced fertilizer in early spring at 1 tablespoon per square foot (30 g/m²) of root zone. The cultivar carries field-documented resistance to apple scab, fire blight, cedar-apple rust, and powdery mildew, reducing the fungicide program required for susceptible crabapples. Hardy to USDA zone 4.Pruning
Prune in late winter (February–March) while the tree is fully dormant. The strongly columnar form requires little shaping beyond removal of crossing, dead, or damaged branches and removal of water sprouts and basal suckers. Heavy pruning stimulates excessive vegetative regrowth and disturbs the narrow canopy silhouette; reduction cuts should be limited to individual wayward branches rather than overall size control.Pruning Schedule
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