The Norway maple (Acer platanoides) is a large deciduous tree with a dense, rounded crown. Native to eastern and central Europe (but not the UK), it has been widely planted across the British Isles in streets, gardens and parks. Since its introduction in the seventeenth century, the Norway maple has become naturalised and now self-seeds in a wide range of habitats, including woods, scrubland and hedges.
These resilient acers are prized as ornamental trees for their characteristic lobed leaves that turn rich yellow, orange and brown in autumn. Acer is from the Latin for ‘sharp or hard’, possibly referring to the pointed tips of the lobes and teeth on the leaves, or to the hardness of the wood. Platanoides means ‘like a plane tree’ as the foliage is shaped similarly to that of species in the Platanus genus, which includes the London plane (Platanus x hispanica).
Norway maple grows quickly in the first few decades and can live for more than 250 years in its native habitat. In North America, it can outcompete the native sugar maple (Acer saccharum) and has a reputation for being an invasive species.
Acer platanoides has scented flowers in April that provide a valuable source of food for early pollinating insects. Once the flowers have been pollinated, they develop into winged fruits known as keys or samaras. The fruits are dispersed by the wind, autorotating with their helicopter-wings as they slowly descend. Winged fruits can stay in the air for longer than non-winged fruits, so they travel on the wind for greater distances.
The wood of the Norway maple is pale cream and relatively hard. It is used for turned objects, crates, furniture and musical instruments including violins. Despite its useful timber, Norway maple has not been grown on a large scale in the UK due to potential problems with grey squirrels stripping the bark.
Identifying Norway maple
Acer platanoides can be confused with sycamore (Acer pseudoplatanus), another naturalised European species introduced into Britain centuries ago, and widely planted from the 1700s. Sycamores can reach 35m in height, taller than Norway maples, but their autumn colour is less spectacular. Unlike sycamore, Norway maple exudes a milky sap when the leaf stalks are broken. Other ways to distinguish between the two species (depending on the time of year) include comparing buds, flowers, leaves and samaras.
- Norway maple has large leaves with five to seven lobes with few sharp teeth and pointed tips. The opposing buds (characteristic to all acers) are deep red. Flowers appear in April before the leaves, and the yellowish-green flowers grow in erect clusters. Fruits are paired and the wings spread on the horizontal or at a wide angle
- Sycamore has large leaves with five coarsely-toothed lobes. Opposing buds are green, and the flowers appear at the same time as the foliage. Like Norway maple, flowers are yellowish-green, but they tend to appear in late April to May, and each hanging flower cluster or corymb is 6-12cm long. Fruits are paired with wings set at a 90° angle
Norway maple could also be mistaken for other members of the genus, such as the native field maple (Acer campestre), Japanese maple (Acer palmatum) or red maple (Acer rubrum).
- Field maple has smaller, smooth-edged leaves, and its paired fruits are spread horizontally
- Japanese maple has five to nine lobes with small teeth and vivid red, orange, purple or yellow autumn foliage depending on the variety
- The samaras of red maple are red and smaller than those of Norway maple. Leaves are also smaller, and they turn brilliant red in autumn
London plane trees have similar foliage to Norway maple, but the leaves are larger and more leathery. Leaves are arranged alternately rather than opposite each other, and the distinctive bark flakes off to reveal buff, grey and cream patches beneath. Globe-shaped fruits dangle down from the branches and remain on the tree until the following spring.
Size, Height and Spread
Norway maple is a large, broadleaf tree growing to 25-30m in height, with a crown that can spread as wide as the tree is tall.
Value to wildlife
The early flowers attract pollinators such as mining bees, flies and beetles. Leafcutter bees cut notches out of the leaves to construct their nests, and moth and fly larvae feed on the foliage. The samaras also provide food for small mammals and birds.
How to grow Norway maple
Acer platanoides is cold hardy throughout the country and does best in full sun or light shade. Its tolerance to pollution, shade and heavy compacted soils makes it a robust and versatile choice for many locations.
Where to plant Norway maple
Norway maples can be planted in the UK, and there are several compact varieties that are suitable for smaller gardens. Deep, fertile, moist but well-drained soil is ideal and, unlike some maples, Acer platanoides copes well with alkaline conditions as well as acid and neutral soils.
How to plant Norway maple
Plant Norway maple as you would any tree.
- Dig a square hole and soften the edges, if necessary, with a garden fork
- Soak the rootball of bare-rooted trees in a bucket of water for half an hour and water containerised plants thoroughly
- Loosen the roots and ensure the top of the rootball sits level with the soil
- Refill the hole with soil, firm gently and mulch with chipped bark or compost
- Stake the tree with a short stake at a 45 degree angle, secured to the trunk with a flexible tree tie
How to prune Norway maple
Acer platanoides needs very little pruning. Simply remove any dead, diseased or damaged material in winter when the tree is dormant to avoid bleeding.
Pests and diseases
In its native habitat, Norway maple suffers few problems but elsewhere the species is susceptible to fungal issues such as Verticilium wilt, tar spot and honey fungus. Some varieties of Norway maple, like ‘Drummondii’, may be prone to leaf scorch, but this is unlikely to cause long-term damage to the health of the tree. Aphids, gall mites, horse chestnut scale and caterpillars can affect the foliage. These insects are part of the natural ecosystem and generally cause little damage, so no treatment is necessary.
Advice on buying a Norway maple
- Acer platanoides varies significantly in size depending on the variety. Consider the final height and spread of the maple you choose to ensure it has enough space to grow
- Specialist tree nurseries offer a range of varieties to buy online
- Always check plants for signs of damage or disease before planting
Where to buy Norway maple trees
Types of Norway maple to grow
Acer platanoides ‘Crimson King’
This majestic variety, also known as the purple Norway maple, has been awarded the Royal Horticultural Society’s Award of Garden Merit (AGM). It has an attractive rounded form and deep crimson foliage that turns orange, brown and maroon in autumn. ‘Crimson King’ is fast-growing and only suitable for larger gardens as it needs plenty of space to spread.
Height x Spread: 25m x 15m
Buy Acer platanoides ‘Crimson King’ from Crocus
Acer platanoides ‘Drummondii’
This elegant variegated acer is also known as the Harlequin Maple. Its deeply-lobed green leaves have wide creamy margins in spring and summer that contrast beautifully with a backdrop of trees and shrubs with darker foliage. It has wonderful orange and yellow autumn colour too. ‘Drummondii’ can sometimes produce stems with foliage that reverts to green. This should be removed as soon as it is seen.
H x S: 12m x 8m
Buy Acer platanoides ‘Drummondii’ from Van Meuwen
Acer platanoides Princeton Gold (‘Prigo’)
Another RHS Award of Garden Merit winner, this striking Norway maple is one of the best for golden foliage. Like many other varieties, Princeton Gold has been included on the list of RHS Plants for Pollinators for its early spring flowers.
H x S: 15m x 15m
Buy Acer platanoides ‘Princeton Gold’ from Primrose
Acer platanoides ‘Crimson Sentry’
This acer is a good tree for medium-sized gardens due to its compact narrow form. It reaches 6m in height with a 2m spread after 20 years, though it will grow bigger given time. Originating as a sport (a natural genetic mutation) of the ‘Crimson King’ variety, it has smaller red leaves than its regal predecessor, and the foliage darkens in summer to a rich purple.
H x S: 10m x 5m
Buy Acer platanoides ‘Crimson Sentry’ from GardeningExpress
Acer platanoides ‘Pacific Sunset’
Admired for its spectacular foliage colour, this variety is a cross between Acer platanoides ’Warrenred’ and Acer truncatum (the Shantung maple). Its large green leaves take on a range of sunset hues in autumn. Reaching 8m in height after 20 years, and continuing to grow to around 12m, ‘Pacific Sunset’ is most suitable for large gardens and parks.
H x S: 15m x 10m
Buy Acer platanoides ‘Pacific Sunset’ from Ornamental Trees
Acer platanoides ‘Globosum’
This unique variety has a spherical crown which is grafted onto a standard Norway maple trunk. Reaching around 5m in height after 25 years, this low maintenance tree is ideal for smaller gardens. It creates structure in rows along pathways and makes a superb focal point when planted as a specimen tree.
H x S: 5m x 5m
Buy Acer platanoides ‘Globosum’ from Chew Valley Trees
from BBC Gardeners World Magazine https://ift.tt/K2rph0d
