Douglas fir

Sun

Full sun; tolerates light shade when young.

Water

Moderate; water young trees deeply during dry spells. Established trees tolerate some seasonal drought, but prolonged heat and dry soil can cause decline.

Soil

Deep, well-drained, slightly acidic to neutral soil. Avoid waterlogged ground, shallow compacted soil and strongly alkaline sites.

Height

60-100 ft (18-30 m) in cultivation; potentially much taller with age

Spread

20-30 ft (6-9 m), sometimes wider on old, open-grown trees

Foliage

Evergreen. Soft, flat green to blue-green needles with pale bands beneath and a resinous scent when crushed. Hanging brown cones have three-pointed bracts projecting between the scales.

Growth

Moderate to fast on suitable sites, often 1-2 ft (0.3-0.6 m) a year once established.

Care needed

Low

• Cold hardy
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   9 ft (2.9 m)

2. After 1 year

   14 ft (4.2 m)

3. After 2 years

   18 ft (5.5 m)

4. After 3 years

   22 ft (6.8 m)

5. After 5 years

   31 ft (9.5 m)

About 16 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Native to

the US and Canada

Growth rate

Fast

• Choose a locally suitable seed source and allow room for a full-sized tree, well clear of buildings and overhead wires.
• Water deeply during dry weather for the first two or three growing seasons; let the soil drain between waterings.
• Maintain a 2-3 in (5-8 cm) layer of organic mulch, keeping it away from the trunk.
• Avoid routine feeding; fertilize only where a soil test or clear deficiency indicates a need.
• Stake only if the root ball moves in wind, and remove supports once the tree is securely rooted.

Pruning. Remove dead, damaged or crossing branches in late winter or early spring, retaining the single leading shoot. Do not top the tree or cut back into bare old wood; use a qualified arborist for large branches.

Early spring

Plant while the soil is workable in cold regions, and water the root ball thoroughly.

Late winter

Inspect the leader and branches; remove dead or damaged growth without reshaping the crown.

Spring

Renew mulch and keep grass away from the young tree's root zone.

Summer

Check soil moisture during dry spells and water young trees deeply when needed.

Late summer

Check for unusual needle yellowing, premature needle loss or shoot dieback.

Autumn

Plant in mild regions while soil remains warm; check that established trees enter winter with moist, freely draining soil.

• Use as a solitary specimen in a large lawn or park-like garden, allowing its lower branches to remain.
• Plant in spacious woodland groups with other locally suitable conifers for a layered evergreen canopy.
• Use along a broad rural boundary for long-term screening, allowing generous spacing rather than treating it as a clipped hedge.
• Underplant the outer canopy with shade-tolerant shrubs and ferns where soil moisture allows.

Garden styles it suits: Pacific Northwest woodland, Woodland, Grand estate, Wildlife garden, Mountain lodge and Winter interest.

Plant it with: Vine maple, Salal, Oregon grape, Western sword fern and Rhododendrons.

Wildlife: Seeds feed squirrels and seed-eating birds, while the evergreen crown provides shelter and nesting sites. Mature trees support many insects, and old trees with cavities provide additional wildlife habitat.

• Needle-cast diseases can cause yellowing and premature needle drop, especially in humid conditions. Allow good airflow, avoid wetting foliage and seek a diagnosis before considering treatment.
• Root rot develops on poorly drained sites. Keep the root collar exposed, avoid overwatering and have leaning or declining trees assessed for safety.
• Aphids and adelgids may produce sticky honeydew or white waxy patches. Small infestations often need no treatment; encourage predators and avoid unnecessary broad-spectrum insecticides.
• Heat and drought stress can brown needles and kill shoots. Mulch and water young trees deeply; avoid planting where summers are persistently hot and dry.

Not known to be toxic to people, cats, dogs or horses. Needles, cones and resin are not suitable animal feed; chewing them may irritate the mouth or stomach, and resin can irritate sensitive skin.

Where it spreads. Spreads aggressively from plantations in parts of New Zealand, particularly South Island high country, where it is managed as a wilding conifer. It also invades some landscapes in Patagonia, Argentina and Chile; check local guidance before planting near natural vegetation.

• Grand fir (Abies grandis)

  Grand fir has upright cones that break apart on the tree and rounded buds. Douglas fir has hanging cones with projecting three-pointed bracts and sharply pointed buds.

• Western hemlock (Tsuga heterophylla)

  Western hemlock usually has a drooping leading shoot, needles of noticeably unequal lengths and much smaller cones without projecting three-pointed bracts.

• Sitka spruce (Picea sitchensis)

  Sitka spruce has stiff, sharply pointed needles attached to woody pegs. Douglas fir needles are softer and lack those persistent pegs.

Douglas fir honours Scottish botanist David Douglas, Pseudotsuga means 'false hemlock', and menziesii honours naturalist Archibald Menzies.

Propagation. Usually grown from seed given a period of cold, moist stratification before sowing. Choose seed of suitable geographic origin; named ornamental forms are generally grafted.

Accepted botanical name

Pseudotsuga menziesii

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Alaska, Alberta, Arizona, British Columbia, California, Colorado, Idaho, Mexico Central, Mexico Northeast, Mexico Northwest, Mexico Southwest and Montana.

Measured

Soil pH 5 to 7.5. Average height 2770 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.