Douglas fir

Douglas fir: how do you recognise it?

Habit

Tree of 30–60 m with a straight trunk and a conical crown about 8 m wide; old trees have a long, bare trunk.

Needles

2–3.5 cm, flat, soft and rounded at the tip, with two pale stripes underneath. When crushed they smell of orange or lemon.

Buds

Pointed, glossy brown and cigar-shaped.

Bark

Smooth with resin blisters at first; on old trees very thick, corky and deeply fissured.

Cones

Hanging, 5–10 cm, with protruding, three-pointed bracts between the scales.

Difference from European silver fir

Silver fir has round, blunt buds and upright cones.

Harvest and fruit: January–December · Pruning: August–September

Identify by feature: Soft needles

Looks like it, but isn’t

• European silver fir Abies alba: round, blunt buds and upright cones. Difference from European silver fir

Why grow it?

• An impressive tree: in Western Europe it can grow over 50 m tall.
• Soft needles that smell of lemon or orange when crushed.
• Strong, resinous timber for beams, cladding, decking and garden sheds.
• Old Douglas fir forests provide nesting sites for birds of prey.

Douglas fir: where does it grow best?

• Sun to partial shade; it tolerates some shade when young.
• Acid, deep, moisture-retentive but free-draining soil; no chalk, no waterlogging and no parched sand.
• Sheltered from strong winds: on shallow or wet soil it can blow over.
• Allow for 30–60 m in height and a crown of about 8 m: only for a wood, a park or a very large garden.

Light

Sun or partial shade

Legal basis

Acid soil

Moisture

Normal

Size

50 m tall, 8 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• Holly: Evergreen and shade-tolerant, for the understorey of a Douglas fir copse.
• Rowan: A small tree with white flowers and orange berries for the sunny edge.
• Silver birch: Pale trunks beside the dark Douglas fir, on the same acid soil.
• Beech: A strong mixture in woodland: beech fills the understorey and its leaves improve the leaf litter.

Good and bad companions

Goes well with

• Like the acid soil under this tree: heather, rhododendron, japanese skimmia, raspberry, highbush blueberry, witch hazel, broom, gorse
• 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

Douglas fir: when and how to plant it?

1. Plant from October to April when the ground isn’t frozen.
2. Choose small, young plants (forestry transplants or a small pot-grown tree); large trees transplant badly.
3. Don’t let the roots of bare-root plants dry out: Douglas fir is very sensitive to this.
4. Protect young trees from deer, which like to rub against the bark.
5. Water after planting and during dry spells in the first year.

Care

Watering

In dry spells during the first few years.

Feeding

Not needed.

Lower branches

In a copse you can saw off the dead lower branches back to the trunk.

Safety

Have an old, large Douglas fir checked by an arborist after a storm or if in doubt.

Tip: Using Douglas fir for decking or a garden shed? Choose heartwood: it is naturally far more durable than the pale sapwood.

Douglas fir: when to prune it?

Pruning months: August–September.

When: Dead, diseased and broken branches can be removed at any time of year. If pruning is needed, do it in August–September.

How:

• In forestry the lower branches are sawn off close to the trunk while the tree is young, for knot-free timber.
• In the garden: don’t prune, and never remove the top.
• Always saw branches off completely, back to the trunk, just outside the branch collar.

Caution: A Douglas fir won’t regrow from old, bare wood: never prune into the bare branches.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Sowing

Pick ripe cones in September–October and let them open. Sow the seeds in spring after a few weeks cold and moist.

Self-sown seedlings

On open, acid soil it sometimes seeds itself; such a seedling is best moved in its first or second year.

Douglas fir: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• Hardy; the young shoots can be damaged by late frosts.
• Wet snow and storms can break branches.

Diseases and pests

• Douglas fir woolly aphid: White, woolly tufts under the needles, which then develop yellow spots and bend. Mainly on young trees; usually harmless.
• Needle cast: Needles that turn brown and drop early, so the crown becomes thin. Choose an airy site.
• Drought: Brown needles and dying tops after long, dry summers, especially on sandy soil.
• Windthrow: On wet or shallow soil a large Douglas fir can be blown over in a storm. Don’t plant it where it could hit the house or the road.

Through the year

• March: Planting season; protect young trees from deer.
• April: Last month for planting.
• May: New growth: watch out for late frost.
• July: Water in dry spells.
• August: Saw off lower branches back to the trunk.
• September: Last month for pruning; pick cones.
• October: Planting season starts.
• November: Plant forestry transplants.

What can you use it for?

Wood

Strong, resinous structural timber (‘Douglas fir’) for beams, cladding, decking and garden sheds.

For wildlife

Old Douglas fir forests provide nesting sites for birds of prey.

Edible and useful

Young shoots (May)

The young shoots in May, with a striking scent of citrus and orange. Good in flavoured sugar, in a cold or hot tea, or finely chopped over a salad or fish.

Needles (January–December)

Needles all year round for tea; they too smell of citrus when crushed.

Storing

Shoots keep for a few days in the fridge, or for months in the freezer. Dried needles keep for a few months in a closed jar.

Caution: You can recognise Douglas fir by its soft needles that smell of citrus when crushed, and by its cones with three-pointed bracts (‘mouse tails’). Never confuse it with yew: flat needles with no citrus smell, red berries, deadly poisonous. Take only a few shoots per branch and never the leading shoot. Pick well away from busy roads and sprayed fields, and never eat anything you have not identified with certainty.

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

Recipes

• Douglas-fir sugar (Dried · 1 jar of 250 g · 15 min + 1–2 days drying)
• Cold-brewed Douglas-fir tea (Tea · 1 litre · 10 min + overnight steeping)
• Lemon cake with Douglas fir tips (Dish · 1 loaf cake of 25 cm · 25 min + 55 min baking)
• Compound butter with Douglas fir tips (Dish · ± 150 g · 10 min + 1 hr setting)

Good for wildlife

Birds

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

Did you know?

• Can grow over 50 m tall in Western Europe and ranks among the tallest trees in the world.
• Named after the Scottish plant collector David Douglas, who sent the seeds to Britain in 1827.
• It is neither a true spruce nor a true fir: its scientific name, Pseudotsuga, means ‘false hemlock’.
• It bears the names of two Scottish plant hunters: Archibald Menzies first recorded it in 1791, and David Douglas brought seed to Europe in 1827.
• Despite its name it is not a true fir or spruce: it has a genus of its own, Pseudotsuga, meaning ‘false hemlock’.