Sugar maple

Sugar maple: how do you recognise it?

Habit

Large tree with a straight trunk and a broad, oval to rounded crown, up to about 20 m high and 12 m wide. Moderate growth rate.

Leaves

Hand-shaped, 8–15 cm, with five lobes and a few coarse teeth; dark green above, paler below. Yellow, orange to red in autumn.

Flowers

Small yellow-green flowers in hanging clusters on long stalks, in April, just before or with the leaves.

Fruit

Paired winged seeds, the familiar ‘helicopters’, ripe in autumn.

Bark

Smooth and grey at first, later dark grey with deep furrows and plates.

Roots

Many fine roots just below the surface: the ground under the crown is dry and shady.

Flowering: April · Harvest and fruit: February–March · Plants: March–April and October–December · Pruning: November–December

Why grow it?

• One of the finest trees for autumn colour: golden yellow, orange and red in one crown.
• A stately shade tree for a large garden, a paddock or a long drive.
• The early flowers provide pollen and nectar for bees in April.
• Fully hardy, to about −35 °C.
• A tree for generations: it grows steadily and lives long.

Sugar maple: where does it grow best?

• Sun to partial shade; autumn colour is best in sun.
• Deep, moist, free-draining sandy or loamy soil, acid to neutral. In wet clay or dry sand it struggles.
• Not surrounded by paving or along a gritted road: it dislikes salt and compacted soil.
• It needs plenty of room: allow 12 m of spread and keep it well away from the house and from pipes.

Light

Sun and partial shade

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

20 m tall, 12 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Snowdrop: Flowers under the bare crown, before the tree comes into leaf.
• Barrenwort: A tough ground cover for the dry shade between the roots.
• Rock cranesbill: Covers the ground under trees and also turns red in autumn.
• Witch hazel: A smaller shrub with yellow to red autumn colour and flowers in winter.

Sugar maple: when and how to plant it?

Plant in March–April and October–December.

1. Plant from October to December or in March–April, when the soil is neither frozen nor waterlogged. Plant bare-root trees only while dormant.
2. Dig a hole twice as wide as the root ball but no deeper, and loosen the bottom and sides.
3. Drive a stake into the hole on the windward side and set the tree next to it at the same depth as in the nursery: the root flare should stay visible.
4. Backfill with the soil you dug out, perhaps with a little compost, and firm it in.
5. Fix the trunk to the stake with a tree tie and give it a few buckets of water.
6. Lay a mulch circle about 1 m across and keep grass away from the trunk.

Care

Water

For the first two or three years, a few buckets a week in dry weather. A mature tree copes on its own, except in a long heatwave.

Feeding

Usually unnecessary. On poor soil, some compost under the crown in spring.

Mulching

A circle of leaf mould or wood chips keeps the young roots cool and moist and the grass at bay.

Stake

Check the tree tie every year so that it does not cut into the trunk. Remove the stake after two or three years.

Trunk

Protect the thin bark of young trees from mowers and strimmers.

Tip: For the first few years, keep a grass-free mulch circle around the trunk and water in dry spells: it will grow away well and give you a firework of colour every autumn.

Sugar maple: when to prune it?

Pruning months: November–December.

When: In November–December, when the tree is fully dormant. In late winter and spring it bleeds heavily from pruning cuts.

How:

• Train young trees to a single central leader: cut out competing tops.
• Remove dead, damaged and crossing branches.
• If you want to walk under the tree, remove the lowest branches gradually, over a few years.
• Saw off large branches in stages and leave the swelling at the base of the branch, the branch collar.

Caution: Do not prune from January to May: it then loses a lot of sap from the wounds.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Collect the ripe winged seeds in autumn and sow them straight away outdoors in a pot or seedbed: winter cold breaks the dormancy and they germinate in spring.

Grafting

Cultivars are grafted by nurseries onto a seedling. For gardeners, seed is the easiest route.

Sugar maple: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy, to about −35 °C: no protection is needed in Belgium.
• Protect the trunks of young trees from rabbits and hares with a tree guard.
• The dormant period in November–December is the time to prune.

Diseases and pests

• Leaf scorch: Brown, dry leaf edges in hot, dry summers or in a spot surrounded by paving. Water deeply and apply a mulch.
• Verticillium wilt: In summer the leaves on one or more branches suddenly wilt; the wood shows greenish streaks. Cut out affected branches and water in dry spells. Badly affected trees rarely recover.
• Aphids: Sticky honeydew under the tree in summer. Usually harmless: ladybirds and birds deal with them.
• Salt and compaction: Along roads it declines: small leaves that colour too early. Choose another spot, or loosen the soil and mulch.

Through the year

• March: Planting. Top up the mulch circle.
• April: Yellow-green flowers for the bees. Leaves unfold. Planting.
• May: Check the tree ties on young trees.
• June: Water young trees in dry spells.
• July: Water in dry spells. Watch for wilting branches.
• August: Water young trees in dry spells.
• October: Golden yellow to fiery red autumn colour. Sow seed. Planting.
• November: Planting. Prune while dormant. Rake leaves for leaf mould.
• December: Prune while dormant. Plant in mild weather.

Edible and useful

Sap (February–March)

Sugar maple is the tree of maple syrup, but also a large tree of around 20 m: only suitable for a large garden, a meadow or a park. You can only tap it once the trunk is at least 30 cm across. The sap runs in late winter, in February and March, when it freezes at night (around −5 °C) and thaws by day (around +5 °C), until the buds burst. In North America that weather lasts for weeks; here such days are fewer, so the flow is shorter and more erratic, and a mild winter sometimes gives almost nothing. Freshly collected, the sap is clear and faintly sweet: drink it as it is, or use it as the water for tea or coffee. It contains only a few per cent sugar: for 1 litre of syrup you boil down 30 to 40 litres of sap.

Storing

Fresh sap spoils quickly, like milk: chill it at once, below 5 °C, and drink or boil it within 2 to 3 days, or freeze it. Unopened, syrup keeps for a year in sterilised bottles in a cool, dark place; once opened, keep it in the fridge.

Caution: Only tap your own tree, or one you have permission for, never in parks, woods or along streets. Choose a strong tree without rot or dead branches, with a trunk at least 30 cm across, and drill one small hole per tree per year, never right next to or above an old hole. Close it after the season with a clean wooden peg. Work with clean, boiled equipment and food-grade containers, cover them and collect the sap every day. Only drink sap that is clear and smells fresh: throw away sap that is cloudy, stringy or smells sour. Boiling down produces litres of steam: do it outdoors, and stay with it, as at the end the syrup easily boils over or catches, and hot syrup causes nasty burns.

Eating and using is at your own risk: see the terms of use.

Recipes

• Tapping sugar maple sap (Sap · up to 5 litres a day · 30 min + 1–4 weeks tapping)
• Maple syrup (Syrup · ± 500 ml from 20 litres of sap · a whole day)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Snap off a leaf stalk and you can tell it from a Norway maple: sugar maple oozes clear sap, Norway maple white milky sap.
• For maple syrup the sap is tapped at the end of winter and boiled down: it takes dozens of litres of sap to make one litre of syrup.
• The sugar maple is the official state tree of several US states, including New York, Vermont and Wisconsin.