Pseudotsuga menziesii

Douglasfir

Pinaceae

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Habitat

  • 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.

© Copyright Mark H. Brand, 1997-2015.

The digital materials (images and text) available from the UConn Plant Database are protected by copyright. Public use via the Internet for non-profit and educational purposes is permitted. Use of the materials for profit is prohibited.

Citation and Acknowledgements: University of Connecticut Plant Database, http://hort.uconn.edu/plants, Mark H. Brand, Department of Plant Science and Landscape Architecture, Storrs, CT 06269-4067 USA.