Pseudotsuga menziesii
Douglasfir
Pinaceae
ExpandHabitat
- native to western North America
- both in Rocky Mountains and coastal regions
- zone 4
Habit and Form
- a large evergreen tree
- coniferous
- in its native haunts it grows to 150' tall or more
- landscape trees reach 60' to 80' tall with 15' to 20' spread
- conical shape
- horizontal branches with pendulous branchlets
Summer Foliage
- leaves are evergreen needles, 1" to 1.5" ling
- leaves are spirally-arranged or 2-ranked
- color varies from blue-green to gray-green or shiny, bright green
Autumn Foliage
- no fall color (evergreen)
- some annual drop of old needles occurs
- winter buds are long-pointed and dark brown
Flowers
- no ornamental value
- flowers are monoecious
- male flowers are axillary and pendulous
- female flowers are terminal
Fruit
- tan cones, 3" to 4" long
- conspicuous 3-pointed bract project from between cone scales
- bracts look like a snake's tongue
Bark
- mature trunks have bark with reddish brown ridges and irregular fissures
- bark on young trunks is smooth with resin blisters
Culture
- culture is similar to that needed by spruce
- moist, slightly acid, well drained soil prefered
- full sun is best
- likes environments with lots of atmospheric moisture
- generally dislikes hot, dry sites
- Rocky Mountain seed source are better than coastal seed sources for tolerating dry sites and colder regions
Landscape Uses
- as a large shade or lawn tree
- a Christmas tree
- accent or specimen
- in groups or clustered
- decoration
Liabilities
- injured by high winds
- cottony aphid
- needle casts (rabdicline)
- twig blight
- several insects, none or which are usually severe
- performs poorly in excessively hot and dry situations
ID Features
- snake tongue-shaped bract projecting from cones
- leaf scars more or less semi-circular
- leaf scars mot raised and twig surface is smooth after needle drop
- winter buds are long-pointed, dark brown and nonresinous
- tree shape is conical
- branches horizontal with pendulous branchlets
Propagation
- by seed
- cultivars are grafted
- cuttings can be rooted, but dificult
Cultivars/Varieties
var. glauca - A naturally-occuring form with bluish-green needles, this selection is also more compact with branches that are upright than the species. 'Blue' is a selected form with blue needles that are said to rival the finest Colorado spruce (Picea pungens). This form is hardy to USDA zone 4.
'Fastigiata' - This variety offers branches that are distinctly upright, forming a spire of dense, green-gray needles.
'Fletcheri' - A common dwarf shrub form, this plant grows 3' to 6' tall by 3' wide and displays blue-green needles.
'Graceful Grace' - Originally discovered as a cultivated plant in Pennsylvania, this fine weeping form features longer needles on an upright plant with gracefully-drooping, lax branches.
'Loggerhead' - This mutation has foliage as per the species, but the habit is dense and mounded. It forms a spreading shrub similar to "Bird's Nest Spruce" (Picea abies 'Nidiformis').
'Little Jon' - A novelty plant, this multi-stemmed dwarf form is globular when young, becoming more broad and upright with age. The needles are dark green on this USDA zone 6 hardy cultivar. 'Hillside Pride' is a similar plant with upright branching.
'Pendula' - An unusual form, this tree features a main trunk that twists as it grows upwards. The lateral branches are spreading and droop for a mounded effect. The plant is clothed in deep green needles. It may only be reliably hardy to USDA zone 6. 'Carnefix Weeping' is a more hardy form (to zone 5), with a variable upright habit, pendulous branches and very rich green needles.