Abies procera is a native North American conifer belonging to the pine family (Pinaceae). This large, majestic evergreen conifer is renowned for its imposing height, symmetrical form, and attractive blue-green needles. It is widely used as a Christmas tree and for its high-quality timber.
I. Appearance and Characteristics
Abies procera, the noble fir, also called red fir and Christmas tree, is a species of fir native to the Cascade Range and Pacific Coast Ranges of the northwestern Pacific Coast of the United States. It occurs at altitudes of 300–1,500 meters (980–4,920 ft).
David Douglas discovered the species in the Cascade Range in the early 19th century, calling it the “noble fir”.
The specific epithet “procera” means “tall”. It is the world’s tallest true fir.
A. procera is a large evergreen conifer with a narrow conic crown, growing up to 70 meters (230 ft) tall and 2 m (6 ft 7 in) in trunk diameter, rarely to 90 m (295 ft) tall and 2.7 m (8 ft 10 in) thick. The bark on young trees is smooth and gray with resin blisters, becoming red-brown, rough and fissured on old trees, usually less than 5 centimeters (2 in) thick; the inner bark is reddish. The leaves are needle-like, 1–3.5 cm (1⁄2–1+1⁄2 in) long, glaucous blue-green above and below with strong stomal bands, and a blunt to notched tip. They are arranged spirally on the shoot, but twisted slightly S-shaped to be upcurved above the shoot.
The cones are erect, 11–22 cm (4+1⁄4–8+3⁄4 in) long and 6 cm (2+1⁄4 in) thick, with the purple scales almost completely hidden by the long exserted yellow-green bract scales; they ripen brown and disintegrate to release the winged seeds in fall. Viable seeds are only produced every few years.
The species can grow for up to 200 years.
The species is very closely related to Abies magnifica (red fir), which replaces it farther southeast in southernmost Oregon and California, being best distinguished by the leaves having a groove along the midrib on the upper side; red fir does not show this. Red fir also tends to have the leaves less closely packed, with the shoot bark visible between the leaves, whereas the shoot is largely hidden in noble fir. Red fir cones also mostly have shorter bracts, except in A. magnifica var. shastensis (Shasta red fir); this variety hybridizes with noble fir and may itself be a hybrid between noble fir and red fir. As opposed to Shasta red fir, noble fir is shade-intolerant, leaving its lower trunk branchless.
Noble fir occurs with Douglas-fir and western hemlock at middle elevations, and with Pacific silver fir and mountain hemlock at higher elevations. It occurs in cool, humid areas similar to those occupied by Pacific silver fir. While it benefits from occasional disturbances (e.g. the 1980 eruption of Mount St. Helens), it is very susceptible to fire but is usually protected by its moist environment. It is relatively resistant to damage from wind, insects or diseases. Although the roots grow slowly, it can survive in very rocky soil as long as it is moist.
II. How to Grow and Care
Sunlight
Noble fir grows both in full sun or part shade with at least four hours of direct sunlight.
Temperature and Humidity
The native habitat of noble fir in the Pacific Northwest is a moist, relatively cool, maritime mountain climate. The tree is not suitable for hot, humid climates.
Watering
The tree needs constant moisture, and it’s important to keep in mind that in its native habitat, three quarters of the precipitation consists of snow that falls between October through March. It would be difficult to duplicate this pattern by irrigation. For this reason noble fir should be grown in a climate with frequent and ample precipitation from fall through spring and with frequent snowfall.
Soil
The tree can grow in a wide range of soil types but the soil needs to be cool, moist, and well-drained. Noble fir prefers deep soil but can sometimes grow in thin, rocky soils. The tree does not tolerate soil with a high pH (alkaline soil).
Fertilizing
The tree requires no fertilization.
Pruning
Noble fir does not require pruning other than removing broken or diseased branches.
Propagation
The most common way to propagate a noble fir tree is from softwood or hardwood cuttings. Softwood cuttings (fresh, young leafed and stem cuttings) and hardwood cuttings (mature cuttings after leaves have been shed), can both be used to propagate. Here’s how.
- Using a pair of sharp pruning shears, cut cleanly through the stems of the noble fir. Cuttings should be about 6 to 8 inches long and as thick as a pencil.
- Use softwood cuttings in late spring (or hardwood cuttings in late fall when the tree is dormant), and place in a soil-filled container. If you are not potting immediately, be sure to keep the cuttings moist.
- Dip the bottom of the cutting into a rooting hormone, which will help to stimulate growth in propagated plants.
- Insert 2/3 of the cutting into the soil and water well, allowing for proper drainage.
- Place the container in a cold area such as a garage or sheltered setting that receives some sunlight so the cuttings can properly root.
- Water more often as the temperature warms and continues tending to the soil over the coming weeks and months.
- When roots have developed, repot the plant in a larger container with fresh potting soil and some fertilizer. Care for it until the tree is large enough to be moved outdoors.
How to Grow from Seeds
You can grow noble fir from the seeds found in its cones which mature in early August. Here’s how:
- Let the cones dry until they are brittle, then shake them to remove the seeds.
- Soak the seeds in water for 24 hours, then place the drained seeds in a sealed plastic bag or an airtight container with a soilless potting mix, such as peat moss or vermiculite.
- Keep them in the fridge for six to eight weeks. This chilling period, called stratification, is necessary to break the plant’s dormancy; without it, the seeds won’t germinate.
- Fill seed trays or small pots with a good potting mix. Plant the seeds no deeper than one-quarter inch, which is about as much soil as is needed to cover the seeds so you don’t see them. Keep soil moist. You can expect the seeds to germinate in a few weeks. The light requirements for growing seedlings are the same as described above.
- Keep the seedlings consistently moist and repot them as they grow. Allow them to grow in pots for three years. Harden off the little trees before moving them into the landscape.
Potting and Repotting
Young noble firs can be grown in containers and then replanted outdoors when they reach a larger more mature size. For smaller varieties that do not reach fuller, taller heights, they can remain in pots, but should be taken outside when cooler weather hits, then brought back inside during warmer temperatures.
Overwintering
Noble firs are unique in that they do not enter full dormancy in the winter, so overwintering care is not required. However, younger firs or those that are being propagated should be sheltered in an area that receives partial sunlight (such as a garage or screened-in porch).
Pests and Diseases
Fir trees in general are often bothered by numerous pests. The most common bugs are aphids, mites, and adelgids, all of which you might find on your Christmas tree after you bring it indoors. More specifically are the Balsam Woolly Adelgid, an aphid-like insect that weakens the tree by infesting the branches and trunk; the spider mite, which sucks sap from the fir needles, causing a speckled appearance to the tree; and the bagworm, a type of caterpillar that can reduce the growth of and even kill the tree.
Noble fir is mainly affected by different diseases caused by fungi: Phytophthora root rot, stem canker, current season needle necrosis (CSNN), and interior needle blight.
III. Uses and Benefits
- Ornamental uses
Noble Fir is widely grown for Christmas trees due to its symmetrical shape, attractive blue-green foliage, and excellent needle retention. Its strong branches are ideal for hanging heavy ornaments.
Noble Fir trees play a vital role in maintaining healthy ecosystems by preventing soil erosion, regulating water cycles, and acting as a carbon sink. They also offer aesthetic value, making them ideal for landscaping and as specimen trees.
- Wildlife uses
Noble Fir provides shelter and nesting sites for birds and small mammals. The seeds are eaten by squirrels, crossbills, and other wildlife.
- Other uses
The Paiute used the foliage to treat coughs and colds.
The superior light and strong wood was recognized early by loggers, who called it “larch” to avoid conflating it with inferior firs. The wood is used for specialized applications such as ladders, general structural purposes and paper manufacture. It may have been used for the frames of the Royal Air Force’s Mosquito bombers during World War II.
David Douglas sent noble fir seeds to Britain in 1830, introducing it to horticulturalists. It is a popular and favored Christmas tree. The prostrate gray cultivar A. procera (Glauca Group) ‘Glauca Prostrata’ has gained the Royal Horticultural Society’s Award of Garden Merit.
