- Mature height
- 10m to 15m (approx.)
- Mature width
- 4m to 6m
Betula pendula 'Nigra' is a deciduous birch grown for its bark. Where standard Silver Birch is bright white, 'Nigra' develops dark, textured bark that becomes the main feature once the leaves drop. The name refers to the bark, not the foliage.
It reaches 10 to 15 metres tall and 4 to 6 metres wide, with fine weeping branches and a light open canopy. Green diamond-shaped leaves turn clear yellow through autumn. Planted in clusters the dark trunks read as a grove. Spaced 5 to 8 metres apart they suit an avenue.
Best in cool to temperate regions: Victoria, Tasmania, the ACT, the NSW Southern Highlands and Tablelands, and elevated parts of South Australia and Western Australia. Full sun to part shade in well-drained, slightly acidic soil. Frost hardy, and holds up well to inland wind.
Two things worth knowing before you plant. The roots are shallow and spreading, so keep it at least 3 metres clear of paving, pipes and pools. And it prefers consistent moisture rather than coping alone through a dry summer, so water deeply through extended dry spells.
Frequently Asked Questions
About Betula pendula 'Nigra' Black Birch
What colour is the foliage?
Green, turning clear yellow in autumn. The name 'Nigra' refers to the dark bark, not the leaves. If you are after purple foliage, the cultivar you want is Betula pendula 'Purpurea', which is a different tree.
How is it different from standard Silver Birch?
The bark. Silver Birch is bright white; 'Nigra' develops dark, textured bark. Habit, leaf and autumn colour are much the same, so the choice comes down to whether you want white or dark trunks in the planting.
How big does it grow?
Around 10 to 15 metres tall and 4 to 6 metres wide in Australian conditions. The canopy stays relatively narrow and light, which is why it works in avenues and groves without dominating a garden.
How fast does it grow?
Around 30 to 60 cm per year in suitable cool to temperate conditions. That is a moderate rate, quicker in good soil with consistent water, slower in poor or dry ground.
Where in Australia does it grow best?
Cool to temperate regions: Victoria, Tasmania, the ACT, the NSW Southern Highlands and Tablelands, and elevated parts of South Australia and Western Australia. It will not perform in subtropical or tropical areas, and struggles in hot dry inland positions.
Are the roots a problem near paving or pipes?
Birch roots are shallow and spreading rather than deep and aggressive. Plant at least 3 metres from paving, pipes, pools and foundations and you will avoid most issues. Avoid planting directly over a service trench.
Does birch trigger hay fever?
Birch pollen is a known spring hay fever trigger, released from the catkins over a few weeks in early spring. If someone in the household is sensitive to tree pollen it is worth planting away from bedroom windows and outdoor living areas, or choosing a different feature tree. We are happy to suggest alternatives.
How far apart should I plant them?
Five to 8 metres apart for an open avenue. Around 2 metres for a dense grove or multi-stem clump effect, where the dark trunks are the point.