Douglas fir greenis perfect for planting alone or on a hedge, creating dense green covers. It is recommended for large gardens in a naturalistic and forest style, especially where we want to quickly obtain tall trees. Ornamental dwarfDouglas fir varietieswill work well in small gardens, on defilements and moors. See whatgreen Douglas fir growinglooks like in the garden. We also advise when andhow to properly trim Douglas firso that the trees remain he althy and attractive.
Douglas fir - Pseudotsuga menziesii
Photo. pixabay.com
What does Douglas fir green look like?
Douglas fir (Pseudotsuga menziesii), also known asDouglas firis a fast-growing conifer native to North America. It is one of the tallest and fastest growing conifers in the world. In its homeland it grows up to 100 m in height, and in Poland there are specimens measuring nearly 50 m.
Douglas fir is a long-lived plant- it can live up to several hundred years. Its silhouette resembles the Norway spruce (Picea abies). It has a dense, compact and regular, broadly conical crown with numerous, highly branched shoots.
Douglas fir needles and very characteristic cones are best recognizedDouglas fir needles are 2-3 cm long, green and shiny, soft, non-pricking, clearly flattened and narrow, with light stripes of wax coating on underside.When rubbed, they give off a pleasant apple-orange aroma. Douglas fir cones are equipped with specific, hook-shaped and strongly elongated three-sectioned seed scales.
Douglas fir in one of the housing estates in Gdańsk
Fig. © Agnieszka Lach
Douglas fir varieties
The most famous variety of Douglas firis its botanical varietyDouglas fir sina(Pseudotsuga menziesii var. Glauca). Both forms are very similar to each other, but the glauca variety has a shorter height (about 20 m) and has thicker, silvery and spiky needles.Douglas Fir is more resistant to drought and frostand therefore it is better suited to gardens in areas with harsher climates.
In Polish nurseries you can findmany interesting varieties of Douglas fir, which are distinguished by an interesting shape and color of needles One of them is Douglas Fir 'Pendula' with strongly dangling side shoots. This variety is also available in the 'Glauca Pendula' version with silvery needles.
Douglas fir needles
Fig. © Agnieszka Lach
Anotherdangle Douglas fir variety is 'Graceful Grace' . The trees naturally lie on the ground, but when tied to a support, they take on a sloping shape.
For small gardens I recommend dwarf varieties of Douglas firThe first noteworthy is the 'Fletcheri' variety with a flattened, cushioned, irregular habit and slow growth (after 10 years the plants reach approx. 50 cm in height), which looks great in rock gardens.
Anotherinteresting variety of Douglas fir is 'Hofman' , the needles of which are covered with an intense blue coating. It is only 4 m high, creating a narrow crown with slightly overhanging side branches.
Also noteworthy isa low variety of Douglas fir 'Holmstrup' , which forms a dense, narrowly conical crown, which over the years forms an almost perfect column, similar in habit to the Eastern Thuja 'Smaragd', popularly referred to as thuja Emerald.
Allof Douglas fir varieties mentioned above are highly resistant to frost and drought , therefore they can be successfully grown in almost all gardens.
Douglas fir cultivation
Douglas fir is an undemanding species . It grows best in a cool and humid marine climate. However, thanks to high adaptability and exceptional tolerance, it can quickly adapt to even worse habitat conditions.
Douglas fir can be grown in a sunny and shaded positionIt is best to plant it in a sheltered place, sheltered from the wind. Trees prefer loamy-sandy soil, fertile, humus, deep and moderately moist, with a slightly acidic reaction.They grow poorly in dry, too sandy and nutrient-poor soils.
Douglas fir cones
Fig. © Agnieszka Lach
Adult Douglas firs have a highly developedand deep-ground root system, therefore they cope well in periods of drought. Young specimens, however, require watering during the summer heat. After planting, cover the ground around Douglas fir with garden bark to reduce water loss from the substrate. However,avoid growing Douglas fir in soils that are too wet , as this leads to the development of diseases.
Young Douglas firs can be damaged by late spring frosts , but they regenerate easily and quickly. Older trees are completely frost-resistant. UnfortunatelyDouglas fir is very sensitive to air pollutionFor this reason, it is not suitable for cultivation in industrial districts and in the centers of large cities and in the vicinity of larger car routes. Air pollution causes Douglas fir needles to brown
Douglas fir does not need frequent fertilizationIt is enough to apply a universal multi-component fertilizer for conifers or a fertilizer against browning of needles once in spring. Douglas fir grown on soils regularly enriched with compost or manure will not require any additional mineral fertilization.
Pruning Douglas fir
Young Douglas firs, several years old, tolerate pruning and forming a hedge very well.
Douglas fir is pruned once a year in early spring(February-March)or at the end of summer(August-September). The shoots are then shortened by 1/3 or 1/2 of their length in order to give the crown the desired shape.
For the first 2-3 years after planting, young Douglas firs do not require shaping pruningas their crowns naturally have a very attractive habit. A shaping cut is also not necessary for drooping Douglas fir varieties.However, it is worthevery spring to make a sanitary cut there, during which all frozen and dry twigs are removed
Older Douglas firs, over 15 years old, should not be pruned too drastically because they will be illHowever, if it is necessary to cut the tree strongly, it is best to spread this procedure over two seasons so as not to weaken the tree with drastic crown cutting.When cutting older Douglas fir at one time, try not to remove more than 30% of the crown
When pruning Douglas fir, do not shorten the guide . Otherwise, the side shoots of the tree will start growing upwards, giving the plant an unattractive, broom-like habit.
MSc Eng. Agnieszka Lach
