Acer platanoides 'Crimson King', Crimson King maple
1 / 5
Broadleaf Deciduous Trees

Acer platanoides 'Crimson King'

Crimson King maple

Sapindaceae

Cultivar; parent species native to Europe and western Asia

At a Glance

TypeTree
HabitSpreading
FoliageDeciduous
Height35-50 feet (10-15 m)
Width25-40 feet (7.5-12 m)
Maturity20 years

Growing Zones

USDA Hardiness Zones

4 - 7
Zone 4
Zone 5
Zone 6
Zone 7
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Drought Tolerant
Maintenancelow

Overview

Acer platanoides 'Crimson King' is a cultivar of Norway maple reaching 35–50 feet (10–15 m) tall and 25–40 feet (7.5–12 m) wide, with a dense, oval to rounded crown similar in form to the species. Leaves are palmate with 5–7 pointed lobes, 4–7 inches (10–18 cm) across, dark maroon-purple from emergence in spring through leaf drop in fall — the defining trait of this cultivar. Foliage color intensifies in full sun; plants in shade develop a more greenish-purple tone by midsummer. As with the species, breaking a leaf petiole releases milky white sap. In early spring, crimson-yellow flowers appear in erect clusters before or with leaf emergence. Paired samaras ripen in fall; seedlings produced are green-leaved, reverting to the species type rather than the purple-leaved cultivar. Growth rate is moderate, 1–1.5 feet (30–45 cm) per year — slightly slower than the species. Surface roots are aggressive and compete with turf and adjacent plantings. Acer platanoides, including 'Crimson King', is listed as invasive in numerous US states and Canadian provinces; seedlings establish readily in forest understories and displace native vegetation.

Native Range

This cultivar has no native range. The parent species, Acer platanoides, is native to Europe and western Asia, from Norway south to the Caucasus and east to the Ural Mountains.

Suggested Uses

Planted as a large shade tree or specimen for foliage color contrast in parks, commercial landscapes, and large residential properties. Use away from natural areas, forest edges, and riparian corridors where seedling escape is a concern. Its use is regulated or discouraged in several US states due to the invasive potential of A. platanoides; consult local guidelines before planting.

How to Identify

Identified by dark maroon-purple palmate leaves with 5–7 pointed lobes maintained from spring through fall — distinguishing it from the green-leaved species and other cultivars. Milky white sap exudes from any broken petiole or stem, a diagnostic trait of A. platanoides shared by all its cultivars. Erect clusters of crimson-yellow flowers appear before leaf emergence in spring. Seedlings from 'Crimson King' are green-leaved, not purple.

Appearance

Size & Dimensions

Height35' - 50'
Width/Spread25' - 40'

Reaches mature size in approximately 20 years

Colors

Flower Colors

red
yellow

Foliage Colors

purple
maroon
dark red

Fall Foliage Colors

purple
maroon

Bloom Information

Bloom Period

~3 weeks
J
F
M
A
M
J
J
A
S
O
N
D
Spring
Blooms late March through April, with erect clusters of crimson-yellow flowers 2–3 inches (5–8 cm) across appearing before or concurrent with leaf emergence. The flower display lasts 2–3 weeks. Samaras ripen September through October and disperse by wind; germination of seedlings is prolific the following spring, with seedlings producing green (not purple) foliage.

Detailed Descriptions

Flower Description

crimson-yellow

Foliage Description

dark maroon-purple spring through fall

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 4-8 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

Soil Requirements

pH Range4.5 - 7.5(Neutral)
357912
Soil Types
loamclaysandsilt
Drainage
well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

15-25 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Water weekly for the first 1–2 growing seasons; established trees tolerate drought, compacted soils, road salt, and air pollution. Foliage holds the deepest maroon-purple tones in full sun locations; part-shade plants develop a more greenish-purple appearance by late summer. Avoid planting within 8–10 feet (2.4–3 m) of pavement or structures due to aggressive surface roots. Monitor adjacent natural areas and remove green-leaved seedlings promptly — they revert to the invasive species type. Verticillium wilt causes branch dieback; remove affected limbs and avoid root zone disturbance.

Pruning

Prune during dormancy (November through February) or in summer (July–August) to reduce sap bleeding from wounds. Remove dead, damaged, or crossing branches. Avoid heavy pruning; large wounds bleed freely. Structural pruning of young trees in years 3–10 reduces the need for corrective work later. Do not prune in spring during active sap flow.

Pruning Schedule

J
F
M
A
M
J
J
A
S
O
N
D
wintersummer

Maintenance Level

low

⚠️ Toxicity Warning

Non-toxic