Douglas fir tree that has been famous for Pseudotsuga, Oregon pine, and false hemlock is indeed a pretty conifer.
It is not the real spruce but an evergreen plant that holds the freshness of the needle-like foliage more than one growing season.
The Douglas spruce offers two varieties, the coastal and the Rocky Mountain cultivar, that give an appealing and elegant look to the landscape.
Therefore, find out more fun douglas fir facts and tips on how to grow the species from the following article.
Douglas Fir Identification
Similar to real pines, the douglas fir bark has resin blisters. When it is still young, the wood surface is smooth with a gray hue.
You might identify the exterior tissue from a mature tree by looking at the deep and wrinkled markings that come in a brown color.
This year-round foliage grows about 24 m tall with a width of 6 meters. Its attractive pyramidal shape features layered twigs. Then, the hanging branches come with drooping vines.
There are many 2-tiered spiral needle-like leaves on each branch. They have a strong gummy volatile fragrant as what camphor trees produce.
The coloration ranges from bluish-green to silvery grayish-green. Also, you will find two white stripes below the needles.
Moreover, it has showy fruits that become ornamental interest during winter, spring, summer, and fall. Before turning into fruits, the Douglas fir tree bears both male and female flowers.
Thus, this conical plant is monoecious. The male blossoms are weeping along the stems. Meanwhile, the female flowers are developing at the top of the twigs.
After one year, the Douglas fir cone will be mature at the size of 10 cm long. The fruits come in a tan hue with an elongated and spherical shape. Likewise, three noticeable sharp bracteal leaves jut out from the scales.
Therefore, the fruits of the false hemlock are different from fir cones that are erect on the branch. The small pollens develop in the spring season.
After the microspores are spreading away, the pollen-bearing scales get dry. Then, you will find lots of them falling on the ground.
Douglas Fir Cultivars
The Douglas fir tree is a native plant from North America. Instead of Pseudotsuga menziessi, several primary varieties of this false hemlock are P. Macrocarpa, P. Lindleyana, P. Sinensis, and P. Japonica.
They have varied size ranges and distributions but give the same function as essential timber trees.
One Douglas fir variety may have different characteristics from one to another.
For instance, the Glauca cultivar has a more compact shape than other species. This tree features erect twigs with blue and green foliage.
Fastigiata is another variety with tight branches. This spire-like plant has grayish-green foliage.
Meanwhile, the Pendula cultivar offers a unique shape since it features twisted stems. Its twigs develop close to the trunk.
Pests and Diseases Management
Some signs that appear when the Douglas fir tree has pest infections, diseases, and other problems are discolored leaves, swollen branches, mottled foliage, and tiny bumps on the leaf surface.
These symptoms are due to the existence of defoliators. They are insects that often eat the needles.
Several common foliage-feeding insects are spruce budworms, tussock moths, dwarf mistletoe, Adelges, and bark beetles.
The symptoms of these pests are loss of leaves, silken webbing, and frass. They tend to feed on the older needles.
Meanwhile, the mature plants are prone to bark beetles since they like felled and damaged trees.
These insects usually lay their eggs under the exterior tissue. Their existence will introduce another pest like a fungus that causes death.
A color change from green to yellow or red is the most common sign of the infected foliage. This symptom occurs in the first attack during spring.
In this season, the beetles also create entrance holes under the bark. Therefore, there are some reddish specks of dust on the stem surface.
Besides, parasitic plants like dwarf mistletoes will absorb the Douglas fir tree’s nutrients by spreading their seeds on the barks.
After germinating through the branch, the infected areas suffer from sufficient nutritions that decrease the growth and vigor.
Generally, some ways to control pest infections are applying insecticides and pruning to reduce future damage.
Cutting down the infected branches is necessary if the tree cannot survive. Removing the dead parts will also be the best treatment to prevent other trees from the damage.
Douglas Fir Diseases
The most remarkable diseases that may affect the Douglas fir tree are needle blight, root rot, and wood decay. These illnesses usually happen in wet and mild conditions.
For example, a foliar problem causes dark markings on the surface before dropping the needles. To prevent new foliage from infection, spray the Douglas fir tree with a fungicide.
Furthermore, some fungi attack the lower part of the Douglas fir tree that cause root diseases. They break in the nutritions or water flow to the head of the foliage. Thus, the plant might become lethargic.
Some signs of root problems are rounding crown, thinning, and yellowing leaves. The other symptom is producing many small cones.
If the infected parts cause the death of the plant, remove the dead sections since they are still infectious and harmful to the healthy trees.
Douglas Fir Care
If you are going to cultivate the Douglas fir tree in your landscape, consider several things to take care of the plant.
Most false hemlock varieties require neutral or acidic soil with humid conditions. After that, make sure that the planting area gets full sun exposure.
However, the Douglas fir tree cannot survive in a hot and dry site. Therefore, you should prepare a well-drained area to grow the plant.
After developing, the young foliage still needs minimal care. A routine watering is necessary during the first growing season, especially in summer.
Moreover, false hemlock should get direct sunshine 4 hours per day. You can let the tree grow as naturally as possible, but treating the plants to shorten the new branches is necessary.
The best time to prune the excessive growth is in the spring season by snipping the long parts to get a tidy form.
Tips on Growing Douglas Fir
Consider preparing a large location to grow the Douglas fir tree in the landscape. A group of this evergreen plant will be a perfect focal point to the surrounding.
You can start cultivating three or seven specimens in an oversized backyard.
Next, plan for planting Douglas fir as privacy screens. Grow each specimen 3 to 5 meters apart.
Meanwhile, if you prefer individual trees, set them at a distance of 216 inches. Then, these evergreens will provide compact fences with a wild mountainous look.
Otherwise, avoid growing the Douglas fir tree in a straight arrangement.
Reel each plant from one side to another and keep it off-center with a losing design. Also, giving varied spacings will evoke a more natural appearance.
Additionally, it is better to grow Douglas-fir plants in garden containers. After getting the appropriate design, the potted trees can be easily moved around.
The planters allow you to play with various distances before replanting them in the soil.
Last but not least, add some companion plants. Mix the Douglas fir tree with Junipers, pines, or other small evergreens.
A rounded shrub such as Mugo helps to highlight the foreground. Interestingly, it can create a majestic backdrop by combining with Pink Dogwood, Japanese Maple, and Eastern Redbud.
Douglas Fir Uses
Some classic landscape uses of the Douglas fir tree are windbreaks, fences, and shelterbelts. To achieve an attractive screening, design the growing plants with zig-zag or staggered styles.
They work best in open locations to break the winds and gasp the snow.
Another function of the Douglas spruce is cutting as a decorative ornament for Christmas. It is due to the soft and pleasant needles that cannot easily fall.
As an ornamental decoration, it often pairs well with Red Twigged Dogwood or a woody shrub Sumac.
Furthermore, the Douglas fir tree, especially the seeds, might bring wildlife values to some native animals.
Songbirds, squirrels, blue grouses, and rabbits feed on them. Goats, sheep, elks, deers, and antelopes usually graze on the leaves and twigs. Besides, the dense foliage is an excellent shelter.
Likewise, the Douglas fir timber is beneficial for building structures to create house frameworks and any commercial projects.
Other functions are making paper from wood pulp, railroad ties, firewood, and furniture.
For culinary uses, the Douglas fir tree can be mixed with brine for marinating. It gives a delicious flavor to sorbet, ice cream, and cocktails.
Also, enjoying its taste of drinking tea is a great idea. Otherwise, the pleasant aroma is great for essential oils.
Similar to other conifers, the pitches and needles have aromatic resins that can be immune boosters.
Use the young leaves or dried older ones to cure colds. They can also be the best treatment to fight infection.
The douglas fir tree contains antimicrobial material and vitamin C to improve skin health. It functions as an astringent to strain inflammation.
In addition, you can use the resinous substance directly on the painful areas to cure the wounds.
Finally, a great mass of the Douglas fir tree creates ponderous pillars that protrude from the landscape.
In short, the Douglas fir tree offers beneficial nutrients for feeding the wildlife as well as providing dense borders in open areas. Enjoy the eye-catching look by setting various planting designs for the garden.