Sycamore

Sycamore: how do you recognise it?

Habit

Large tree of 25–35 m with a broad, domed, dense crown.

Leaf

Opposite, 10–20 cm, with 5 coarsely and irregularly toothed lobes; underside grey-green. Leaf stalk often red, without milky sap.

Bark

Grey, flaking in plates on older trees. Buds green.

Flower

Yellow-green flowers in hanging clusters, appearing with the leaves.

Fruit

Winged fruits with wings at an acute to right angle.

Difference from Norway maple

Norway maple has long, pointed teeth on the lobes and milky sap in the leaf stalk.

Difference from London plane

London plane has alternate leaves.

Flowering: May · Pruning: July–October

Identify by feature: Palmate leaves · Opposite leaves · Hanging flower clusters · Winged seeds · Peeling bark

Looks like it, but isn’t

• Norway maple Acer platanoides: long, pointed teeth on the lobes, and milky sap. Difference from Norway maple
• London plane Platanus × hispanica: leaves are alternate. Difference from London plane

Why grow it?

• Extremely tough: tolerates wind, sea air and almost any soil, which makes it a good tree for a windbreak.
• Flowers for bees in April–May.
• Grows fast and gives plenty of shade in a park or a large garden.
• Highly prized wood, for violin backs, furniture and chopping boards.

Sycamore: where does it grow best?

• Sun to partial shade; young trees tolerate a lot of shade.
• Almost any soil, preferably moist and fertile; not ground that stays under water for long.
• Tolerates wind and sea air: suitable for a windbreak on the coast or in open country.
• Allow for a crown up to 18 m wide: only for a park, a large garden, a hedgerow or a windbreak, and never next to a horse paddock.

Light

Sun or partial shade

Legal basis

Any garden soil

Moisture

Normal

Size

30 m tall, 18 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• Hazel: A native shrub for the understorey of a hedgerow or windbreak.
• Holly: Evergreen and shade-tolerant under a dense crown.
• Wood anemone: Flowers in spring, before the crown closes.
• Elder: Grows fast alongside it in a windbreak and gives blossom and berries.

Good and bad companions

Goes well with

• Tolerate the shade under this tree: oregon grape, rhododendron, oleaster, japanese skimmia, garden privet, camellia, laurustinus, box-leaved honeysuckle

Best kept away from

• Sun-loving plants get too little light under the dense crown: english lavender, heather, butterfly bush, blackthorn, highbush blueberry, sea buckthorn, japanese rose, broom

Sycamore: when and how to plant it?

1. Plant from November to March, bare-root or with a root ball.
2. Don’t plant it near a field or paddock with horses, not even just over the fence: the seeds blow a long way.
3. In a windbreak or hedgerow: space the trees widely and fill in with native shrubs.
4. Put a stake on the windward side and water generously after planting.

Care

Watering

In dry spells during the first year; after that it copes.

Feeding

Not needed.

Seedlings

Pull up seedlings in the garden in good time: they come up everywhere and are deeply rooted after a few years.

Horses

If sycamores grow near a paddock, gather the seeds in autumn, remove the seedlings in spring and provide extra hay when grass is short.

Tip: Want a maple in a small garden? Choose the slow, small ‘Brilliantissimum’ with salmon-pink young leaves – but that too is a sycamore: not near horses.

Sycamore: when to prune it?

Pruning months: July–October.

When: In summer or early autumn (July–October).

How:

• Prune little; train a young tree on a single central leader.
• Pull up seedlings in the garden in good time, as they come up everywhere.
• Cut large branches in three steps, just outside the branch collar.

Caution: Don’t prune in late winter or spring: it bleeds heavily then. Do you see a black, sooty layer under loose bark (sooty bark disease)? Don’t saw it yourself: the spores are harmful to the lungs.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Sowing

Usually not needed: it seeds itself everywhere. If you still want to sow, sow the winged fruits outdoors in autumn.

Grafting

Ornamental forms such as ‘Brilliantissimum’, with salmon-pink young leaves, are grafted; that is a job for the nursery.

Sycamore: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• Fully hardy, even in open, windy places.
• In winter you recognise it by its fat green buds and, on older trees, the flaking bark.

Diseases and pests

• Tar spot: Large black spots on the leaves in late summer. Harmless; rake up the leaves in autumn.
• Sooty bark disease: After hot, dry summers, branches die back, the bark comes loose and underneath is a black, sooty layer of spores. The spores are harmful to the lungs: have the tree felled by a professional wearing protective equipment.
• Aphids and honeydew: Sticky drops on cars, benches and the patio under the tree. A nuisance but harmless.
• Seedlings: Hundreds of seedlings in borders, hedges and between paving slabs. Pull them up while young.

Through the year

• March: Last month for planting.
• April: Flowers in hanging clusters with the leaves; seedlings come up: remove them near horse paddocks.
• May: Weed out seedlings in the garden and near paddocks.
• July: Summer pruning: the right time for maples.
• August: Summer pruning; tar spots on the leaves.
• September: Pruning still possible; the ‘helicopters’ ripen.
• October: Seeds blow away: keep horses away from fallen seed. Last month for pruning.
• November: Planting season starts; clear up leaves with tar spot.

What can you use it for?

Wood

Highly prized wood: violin backs (flamed maple), furniture and chopping boards.

Food and drink

The spring sap can be boiled down to syrup, though it is less sweet than that of the sugar maple.

For wildlife

Flowers for bees.

Caution: Seeds and seedlings are poisonous to horses (atypical myopathy). Don’t plant it near horse paddocks.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Ladybirds

Aphids on the plant are food for ladybirds and their larvae.

Birds

Berries, seeds or insects as food, or a place to nest.

Did you know?

• Seeds itself everywhere: the ‘helicopters’ float far away on the wind.
• Flamed sycamore wood is prized for the backs of violins.
• The spring sap can be boiled down to syrup, though it is less sweet than that of the sugar maple.
• The name pseudoplatanus means ‘false plane’, after the leaf.
• Its English name, sycamore, arose from confusion with the sycomore fig of the Bible (Ficus sycomorus); pseudoplatanus means ‘false plane’.
• The black spots often seen on the leaves in late summer are tar spot, a harmless fungus that is sensitive to sulphur dioxide pollution.