Norway maple

Sun

Full sun to partial shade; best crown development in an open, sunny position.

Water

Moderate; water regularly while establishing. Established trees tolerate short dry periods, but prolonged drought can scorch leaves.

Soil

Adaptable to clay, loam and sandy soils, including alkaline ground; prefers moist, well-drained soil. Avoid persistently waterlogged sites.

Height

40-60 ft (12-18 m)

Spread

30-50 ft (9-15 m)

Flowers

Clusters of yellow-green flowers in spring, just before or as the leaves unfold.

Foliage

Large, opposite, five- to seven-lobed green leaves, usually turning yellow in autumn. Broken leaf stalks release milky sap.

Growth

Moderate to fast when young, slowing with age.

Care needed

Medium

• Pollinators
• Cold hardy
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   7 ft (2 m)

2. After 1 year

   9 ft (2.7 m)

3. After 2 years

   11 ft (3.3 m)

4. After 3 years

   13 ft (4 m)

5. After 5 years

   17 ft (5.3 m)

About 20 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Invasive in

the US and Canada

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Moderate

• Plant with the root flare visible at soil level, well away from paving, drains and buildings to allow for the mature crown and spreading roots.
• Water deeply during dry spells for the first two or three growing seasons, moistening the root ball and surrounding soil.
• Maintain a 2-3 in (5-8 cm) layer of organic mulch over the root zone, keeping it clear of the trunk.
• Do not routinely fertilise; feed only if a soil test or diagnosed deficiency indicates a need.
• Avoid digging, raising soil levels or laying new paving over established roots.
• Pull unwanted seedlings while small, especially near woodland and other natural areas.

Pruning. Prune in late summer to remove dead, damaged or crossing branches and establish a sound framework while the tree is young; avoid heavy pruning and topping. Maples can bleed heavily if cut in late winter or spring, and large limbs should be assessed by a qualified arborist.

Late winter

Inspect the bare crown for damaged branches and weak forks; arrange professional assessment of major defects.

Spring

Refresh mulch without covering the root flare, and pull newly germinated seedlings.

Late spring

Check leaves for aphids and developing disease; tolerate minor cosmetic damage rather than spraying routinely.

Summer

Water young trees deeply during dry weather and check that ties are not cutting into the bark.

Late summer

Carry out necessary light formative pruning.

Autumn

Plant where suitable and permitted; collect fallen leaves from lawns and paths, and remove unwanted seedlings.

• A broad shade canopy over a large lawn, where its mature size and surface roots have room.
• A specimen tree in a spacious park-like garden, providing a strong rounded outline.
• An avenue tree on generous sites, with enough unpaved rooting space and clearance from buildings.
• An upper canopy above established dry-shade planting, using small plants to minimise disturbance to tree roots.

Garden styles it suits: Traditional, Grand estate, Formal, English country, Autumn colour and Urban city garden.

Plant it with: Barrenwort, Bigroot geranium, Stinking hellebore, Ivy-leaved cyclamen and Snowdrops.

Wildlife: Spring flowers provide nectar and pollen for insects, and the crown offers shelter and nesting sites for birds. In invaded North American woodland, dense shade and abundant seedlings can displace native plants and reduce habitat quality.

• Dense shade and shallow roots leave lawns thin and borders dry: replace struggling grass with mulch and suitable dry-shade plants; avoid cutting major roots.
• Aphids cause sticky honeydew beneath the crown: tolerate light infestations and encourage natural predators; avoid placing seating or parked cars directly below affected branches.
• Tar spot produces black patches on leaves: usually cosmetic; collect fallen leaves where practical to reduce local carry-over.
• Verticillium wilt can cause sudden branch dieback: seek a diagnosis, remove dead wood and reduce drought stress; there is no curative treatment.

Norway maple is not known to be toxic to cats, dogs, horses or people. Do not confuse it with red maple, whose wilted leaves can poison horses, or sycamore maple, whose seeds and seedlings can cause atypical myopathy in horses.

Where it spreads. Spreads aggressively by seed in parts of North America, especially the northeastern and mid-Atlantic United States, parts of the upper Midwest, and southern Ontario and Quebec in Canada. It is listed as invasive or restricted in several jurisdictions, including Massachusetts; check local planting and sales rules before buying.

• Sugar maple (Acer saccharum)

  Sugar maple has clear rather than milky sap in its leaf stalks, generally more rounded sinuses between the lobes, and paired seed wings that form a narrower angle.

• Sycamore maple (Acer pseudoplatanus)

  Sycamore maple has coarsely toothed leaves, often greyish beneath, and hanging flower clusters. Norway maple has sharper-pointed lobes, milky leaf-stalk sap and upright flower clusters.

• Field maple (Acer campestre)

  Field maple has much smaller leaves with blunt, rounded lobes and usually forms a smaller tree. Both can have milky leaf-stalk sap and widely spreading seed wings.

Acer is the Latin name for maple, platanoides means resembling a plane tree, and Norway maple refers to its occurrence in Norway within its wider native range.

Propagation. Species trees can be raised from seed given a period of cold, moist stratification; outdoor autumn sowing can provide this naturally. Named cultivars are usually budded or grafted and do not come true from seed. Do not propagate where the tree is invasive or restricted.

Accepted botanical name

Acer platanoides

In the US and Canada

Introduced in Canada and the lower 48 states.

Native range

Afghanistan, Albania, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Rus, Czechoslovakia, East European Russia, Finland and France.

Measured

Soil pH 4.8 to 6.8. Average height 1940 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.