Norway Maple 'Crimson King' (Acer platanoides 'Crimson King'): Bold Purple Foliage All Season

'Crimson King' is a popular cultivar of Norway maple prized for its deep maroon-purple leaves that hold their color from spring through fall. Its dense, rounded canopy and tolerance of urban conditions make it a common street and shade tree, though its aggressive root system and invasive potential in some regions warrant caution.

Botanical Profile

• Family: Sapindaceae (soapberry family)
• Genus: Acer
• Species: platanoides
• Cultivar: 'Crimson King'

Foliage and Form

Leaves emerge deep purple in spring, mature to a rich maroon, and turn bronze to reddish-brown in fall. The tree grows 35–45 feet tall with a similar spread, forming a dense, symmetrical oval to rounded crown. Yellow-green flower clusters appear in early spring before leaves, followed by typical maple samaras (helicopter seeds).

Culture and Concerns

Adaptable to a wide range of soils, including clay, alkaline, and compacted urban soils. Tolerates pollution, salt, and drought once established. Hardy in USDA zones 4–7. However, its shallow, dense root system makes underplanting difficult and can lift sidewalks. In parts of the Northeast and Pacific Northwest, Norway maple is considered invasive, displacing native vegetation. Check local regulations before planting.

Landscape Uses

Shade tree, street tree (where permitted), specimen for purple foliage contrast. Best in large lawns or parks where roots have space.