Himalayan birch

Himalayan birch: how do you recognise it?

Habit

Upright tree of 10–15 m with an open, oval crown; often grown as a multi-stemmed tree.

Bark

In the white forms brilliant white and smooth, with horizontal bands; sometimes peels in thin sheets.

Leaves

Oval, 5–12 cm, with a toothed edge; dark green, golden yellow in autumn.

Flowers

Hanging, yellow-brown male catkins in April, short upright female catkins.

Roots

Shallow and wide-spreading: the soil under the tree dries out quickly.

Flowering: April · Plants: March–April and October–December · Pruning: August–October

Why grow it?

• Brilliant white trunks that stand out all year, but especially in winter.
• A light, open crown that casts little shade: plenty will still grow beneath it.
• Golden-yellow autumn colour.
• Stunning as a multi-stemmed tree, as a focal point in a lawn or in front of a dark hedge.
• Fully hardy and low-maintenance.

Himalayan birch: where does it grow best?

• Sun or partial shade; in sun the crown stays denser and the trunk looks its best.
• Sandy, loamy or clay soil, acid to neutral, preferably humus-rich.
• Moist soil: the shallow roots cannot cope with long droughts.
• Against a dark background, such as a yew hedge, the white stems show up best.
• Allow 5–6 m from the house and other trees.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Acid or neutral

Moisture

Normal

Size

15 m tall, 8 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Yew: A dark hedge or backdrop that makes the white stems glow.
• Dogwood: Red stems beside white trunks: a classic winter picture.
• Snowdrop: A white carpet under the bare crown in February.
• Barrenwort: A tough ground cover that tolerates the dry shade under the birch.

Himalayan birch: 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 ground is neither frozen nor waterlogged.
2. Dig a hole twice as wide as the root ball but no deeper, and mix in some compost.
3. Set the tree so the root flare is just at ground level. For a multi-stemmed effect you can also plant three young trees close together.
4. Put in a short stake at an angle on the windward side and tie the trunk loosely.
5. Water in with a large bucket of water straight away, even if it is raining.
6. Spread a mulch around the base, but keep it clear of the trunk.

Care

Watering

For the first three years, a few buckets a week in dry weather. Later too in long droughts, as the roots are shallow.

Feeding

Some compost under the crown in spring. Nothing more is needed.

Mulching

A layer of leaf mould keeps the soil cool and moist.

Washing the stems

In winter you can wash off green algae with lukewarm water and a soft brush.

Underplanting

Choose tough plants that cope with dry shade, as the roots compete for water.

Tip: Plant it as a multi-stemmed tree in front of a dark background, so the white stems really stand out. Wash the stems once a year in winter with water and a soft brush to keep them brilliant white.

Himalayan birch: when to prune it?

Pruning months: August–October.

When: Only when needed, from August to October, when the tree does not bleed.

How:

• Remove dead, damaged or crossing branches.
• Gradually remove the lowest side branches to show more of the white stems.
• Cut just outside the swollen collar at the base of the branch, without leaving a stub.
• Do not remove large branches all at once; spread the work over a few years.

Caution: Never prune in late winter or spring: the birch then bleeds heavily from the pruning cuts.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow fresh seed thinly in autumn or spring on moist seed compost and barely cover it. Seedlings do not always have white bark.

Grafting

Nurseries graft the white cultivars onto a rootstock in winter. For a guaranteed white trunk, buy a grafted tree.

Himalayan birch: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection is needed in Belgium.
• The white stems look their best in winter, especially in low sun or against a dark hedge.
• Do not prune in winter or spring: wait until August.
• Stand a young tree in a pot in a sheltered spot, with the pot wrapped in hessian.

Diseases and pests

• Green staining: Algae turn the white trunk greenish. Wash it in winter with water and a soft brush, without a pressure washer.
• Aphids and honeydew: Sticky drops under the tree in summer, sometimes with black sooty mould. Usually harmless; do not plant it over a terrace or driveway.
• Birch rust: Small orange spots on the undersides of the leaves in late summer and early leaf drop. Clear up fallen leaves.
• Drought: Yellow leaves and early leaf drop in dry summers. Water generously and mulch the soil.

Through the year

• January: White stems at their finest. Wash off green staining if needed.
• February: Clean the stems with water and a soft brush.
• March: Plant. Do not prune: the tree bleeds.
• April: Hanging catkins in flower. Plant.
• May: Water young trees in dry weather.
• July: Water in dry weather. Watch for aphids.
• August: Prune if needed. Water in dry weather.
• September: Prune if needed.
• October: Golden autumn colour. Last pruning. Plant.
• November: Plant. Clear up fallen leaves.
• December: Plant. The white stems decorate the garden.

Did you know?

• In the Himalaya the thin bark of this birch was used as writing material for centuries; old manuscripts on birch bark still survive.
• The white colour of birch bark comes from betulin, a substance in the outer layers of the bark.
• The cultivar ‘Doorenbos’ is named after S.G.A. Doorenbos, a former director of the parks department of The Hague.