Concolor fir growth rate

How Fast Does the White Fir Tree Grow in a Year?

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The white fir tree is an evergreen specimen and one of the chief sources of the Christmas trees that reside in homes through December. Widely utilized in urban landscaping as an ornamental tree, the white fir grows at a modest pace. Gardeners wishing to grow their own Christmas tree will have to wait several years.

Rate of Growth

The white fir (Abies concolor) is also called a concolor fir and grows at a slow to medium rate. According to the Arbor Day Foundation, a slow rate of growth denotes a tree that grows 12 inches or less each year, while medium growth describes between 13 and 24 inches annually. Based on these calculations, you can expect the white fir to grow somewhere between 1 and 2 feet a year.

Mature Size

The white fir claims a light-colored bark and produces needles that are a combination of silver, blue and green. Its rate of growth will see it achieve a mature height of at least 50 feet accompanied by a spread of 20 feet. The cultural environment in which the white fir tree is planted may dictate how fast it grows in a year. It prefers full sunshine mixed with partial shade.

Environment

The white fir thrives in U.S. Department of Agriculture hardiness zones 4 through 7, an area that encompasses the colder sections of the U.S. The tree will grow more slowly over the course of a year’s time if it is forced to grow in the more southern or desert locales of the country. It demands conditions that are cool and moist with soil that is rich and well drained. The natural range of the tree is the Sierra and Rocky mountains.

Pests and Disease

Somewhat drought tolerant and able to withstand high levels of alkaline in the soil, the white fir will grow nicely as an ornamental tree in cooler sections of the Midwest and East. Like all plants, a variety of pests and disease can slow the rate of growth the tree experiences each year. Flatheaded fir borers, fir engravers, bark beetles and needle midges are among the insects that can weaken the vitality of the tree, while armillaria root rot is a severe disease of the fir.

PLANT PROFILE:White Fir

Abies concolor

Description & Overview

White Fir is an outstanding handsome, large evergreen with distinctive soft, blue-green needles. Its large cones mature to purple-brown, contrasting with the thick foliage. The best fir for the Midwest, as long as it’s planted in well-drained soil.

Core Characteristics

Wisconsin Native: No – Native to North America USDA Hardiness Zone: to zone 4 Mature Height: 30-50 feet Mature Spread: 15-30 feet Growth Rate: Slow Growth Form: Upright, Conical, Dense Light Requirements: Full Sun to Partial Shade Site Requirements: Requires well-drained soil, sensitive to excess moisture Flower: Monoecious, insignificant reddish male cones, small (0.5 inch), erect purple female cones Bloom Period: May Foliage: Blue-Green needles, long Fall Color: N/A-Evergreen Urban Approved: No Fruit Notes: 3-6 inch cones, mature to brown, disintegrate in wind to spread seed, good crops every 2-5 years

Suggested Uses:

White Fir contrasts with other evergreens due to its lighter needles. It’s an excellent alternative to Blue Spruce as long as your soils are well drained. Use it as a specimen tree or a component of a screen. Take care to not site next to busy roadways as the tree is moderately susceptible to ozone pollution.

Wildlife Value:

As with Balsam Fir, White Fir seeds are an excellent food source for birds and small mammals. The dense needles give good cover to our avian communities. Squirrels and chipmunks can often be seen eating the seeds over winter.

Maintenance Tips:

White Fir has a symbiotic relationship with mycorrhizae fungus. When planting the tree, be sure to use a product to inoculate the soil with this beneficial fungus as it will improve tree vigor.

White Fir is beautiful when left alone, no shearing required. If you desire to raise the canopy, prune White Fir during the winter months. Branches that are touching the ground can be removed to improve air circulation.

Although many trees will benefit from watering in extended drought, White Fir is adapted to the dry, rocky soils of the Rocky Mountains. Water only when there has been extensive drought, and water sparingly. Watering during the establishment period is still important, and care should be taken to make sure newly planted White Fir has enough moisture to establish good roots. Maintaining a mulch ring at the base is also beneficial as it reduces the need to water and slowly adds nutrients to the soil.

Pests/Problems:

White Fir has few insect and disease issues. Armillaria Root Rot and Canker are not usually treatable and are best avoided by maintaining tree vigor. Occasionally White Fir will develop Blight (Diplodia, Sphaeropsis, and Sirococcus), Fungal Needlecast, Phytophthora Root Rot, and Rust diseases. These can be treated by a plant health care professional. Contact an arborist if you notice significant dieback or any sever changes in the health of the tree.

As White Fir is moderately susceptible to ozone pollution, do not site the tree near roadways with heavy traffic.

Early or late cold snaps may kill developing buds and foliage. The plant usually flushes through this dieback with no issues.

The thin bark of White Fir is susceptible to mechanical damage. Be careful when mowing or weeding around the trunk to prevent scarring the tissue

Leaf Lore:

White Fir is native to the western United States with two distinct populations. One exists in California and the other in the Rocky Mountains. Its range is restricted by wildfire, but efforts of fire suppression during the 20th century have extended its range beyond pre-settlement levels. Although it performs best in full sun, White Fir is tolerant of some shade and will colonize areas that have not experienced fire in several years. It is commonly found with Quaking Aspen and Blue Spruce, and has invaded Douglas Fir when there is extensive fire suppression.

White Fir will tolerate partial shade, which is what allows it colonize other forests. However, its best growth and form is achieved in sites with full sun. In shade, it is more open and airy, and does not provide much screening value.

White Fir is drought tolerant and prefers dry soils. In the western United States, best growth was observed in years where annual moisture was below average.

Companion Plants:

As White Fir prefers low moisture, you should not site it with plants that have higher water requirements. Use drought-tolerant trees, shrubs, and perennials where you intend to plant White Fir. Some options would be False Blue Indigo, Butterflyweed, Bush Cinquefoil, or Black Hills Spruce.

WHITE FIR BENCHCARD

Plant Database

Habitat

  • native to the Rocky Mountains of the western United States; from Canada to California
  • zone 3

Habit and Form

  • evergreen tree
  • 50′ to 75′ tall by 20′ to 30′ wide, but can reach over 100′ tall
  • pyramidal in shape, holding a dense, formal shape well, even with age
  • medium to coarse texture
  • slow to medium growth rate

Summer Foliage

  • needles are 2″ to 3″ long
  • needles arranged horizontally on the stem, curving up and out, much like a “rib cage”
  • needles are glaucous on both-sides giving it a blue cast to the upper and underside
  • needles have 2 white stomatal lines on underside
  • buds are resinous

Autumn Foliage

  • no fall color (evergreen)

Flowers

  • no ornamental value
  • monoecious

Fruit

  • brown cones, green when immature
  • cylindrical
  • 4″ to 5″ long
  • cones shatter when mature
  • cones borne on the upper third of the tree

Bark

  • smooth, except for occasional resin blisters
  • bark has a whitish gray color
  • new stems are yellow-green in color and are somewhat hairy

Culture

  • easily transplanted
  • tolerant of most climates and city conditions
  • prefers a deep, well-drained soil with adequate moisture, but less fussy about soil moisture than other Abies sp.
  • full sun
  • most adaptable of all Abies sp. to cultivation

Landscape Uses

  • specimen tree, has exceptional foliage
  • adds nice color to typical green winter foliage
  • less likely to fail than other true firs under a range of landscape situations

Liabilities

  • formal form and blue color can be imposing in some landscape situations
  • often damaged by deer

ID Features

  • needles are similar in color on top and bottom
  • smooth bark with resin blisters
  • longest needles of commonly seen firs
  • resinous buds
  • circular leaf scars

Propagation

  • by seed, stratification period required for good germination

Cultivars/Varieties

‘Candicans’ – Notable for its intense silvery-blue needles, perhaps the bluest of all Abies.

‘Compacta’ – A handsome dwarf form with an irregular habit and blue needles.

‘Dwarf Globe’ – A dwarf form (to 3′ tall) with needles that are borne densely and bluish-green in color.

‘Glenmore’ – A more compact variety than the species with grey-blue needles that are longer than usual.

‘Gable’s Weeping’ – An unusual, slow-growing form that forms a mound of drooping branches.

‘Violacea’ – Beautiful form with intense silvery-blue needles. Often grafted on species understock.

White Fir

Native to the western mountain states, the white fir (Abies concolor) also known as concolor fir, has been planted in Iowa for ornamental and windbreak use. Where native, it is a large tree 150 to 220 feet tall. In Iowa, it reaches a height of 50 to 80 feet. It is a hardy tree and grows on a wide range of soils.


White Fir Tree – Photo by Paul Wray, Iowa State University

Hardiness: Zones 3 through 7

Growth Rate: Slow

Mature Shape: Narrow, pyramidal with horizontal branches. Lower branches may take on a drooping appearance.

Height: 30-50 feet

Width: 15-30 feet

Site Requirements: Plant trees in full sun to light shade with moist, well-drained soils. Concolor firs are tolerant of heat and drought.

Leaves: Needles that spread almost at right angles in two rows; flat, flexible; light blue-green with whitish lines on top and bottom surfaces

Flowering Dates: May – June

Seed Dispersal Dates: September – October

Seed Bearing Age: 40 years

Seed Bearing Frequency: Every 2 to 4 years

Seed Stratification: Prechill for 1 month at 34°F to 40°F

The needles are flat and blunt-pointed and are 1 to 2 inches long. They stand out distinctly from two sides of the branch and are curved. The young needles have a bluish cast. As they mature they become more pale and take on a whitish cast, which, with the light-colored bark, gives the tree its name.

The cones are 2 to 4 inches long, occurring on the upper branches where they stand upright. They are ashen-tinged olive green to purple in color. When mature they break up while still on the tree.

The comparatively smooth bark is ashy gray and covered with conspicuous resin blisters. On older trees the bark thickens and breaks into deep, longitudinal furrows.


White Fir Fruit – Photo by Paul Wray, Iowa State University


White Fir Twig – Photo by Paul Wray, Iowa State University


White Fir Leaves – Photo by Paul Wray, Iowa State University


White Fir Tree – Photo by Paul Wray, Iowa State University

Say it isn’t so! This beautiful forest I look out onto every day is a forest of weeds? California white fir (Abies concolor) certainly does get a bad rap, its tarnished reputation stemming primarily from the subject of fire. White fir is easily destroyed by fire as its wood is soft, its bark relatively thin, and its lower branches provide an easy ladder for flames to climb. Yet here’s the conundrum — white fir grows best when it has fire to thin its stands. If fire is not prevalent or fire management keeps fires at bay, the tree can take over a forest and attract swaths of pests and diseases. The fir engraver beetle (Scolytus ventralis), better known as one of the bark beetles, causes high mortality in white fir stands. On the other hand, white fir is drought resistant and grows well in disturbed areas, thus the nickname “weed tree.” In our part of the Sierra, white fir mixes with red fir, ponderosa pine, sugar pine, and incense cedar.

Red fir (Abies magnifca) is not as vulnerable to fire as white fir. It’s stouter, with thicker bark. The red fir can grow up to 230 feet and 10 feet in diameter, whereas the white fir stands 60 to 200 feet high and up to 4 feet across. Red fir grows at higher elevations than white fir, although the two firs are often seen together. White fir is prevalent in Truckee.

The best way to identify the two firs is to look at the needles, which are shorter than pine needles. If the needles are flat with two white lines on their undersides and come out from the branch at a perfect right angle, the tree is a white fir. If the needles are four-sided, easy to roll between fingertips, and have a hockey stick-like curve where they attach to the branch, it’s a red fir. My secret mnemonic is that hockey is a bloody sport, hence red fir. White fir branchlets extend laterally as flat sprays, while red fir branchlets curve downwards then up at the ends. New growth in white fir — fluorescent, green fir needles — is soft and rubbery at the end of the branches and is edible with a limey, bitter taste; the new needles also smell citrusy. I often munch them along the trail, as do deer. The bark isn’t always easily comparable but the long, vertical plates on the white fir are white/gray and on the red fir, dark red/brown. Much easier to see are the colors underneath the outer bark, yellow-gold in the white fir and red-purple in the red fir.

And then the cones — they defy gravity! Hand-sized, barrel-shaped, the heavy cones stand upright on the tips of the branches. I saw a stand of firs once where the sun backlit the cones, highlighting them as if they were lit candles, which is often how we see firs, as perfectly shaped Christmas trees twinkling bright in our living rooms.

Do you have a question about our region’s natural world? Email [email protected]

White Fir Facts: What Is A Concolor Fir Tree

What is a concolor fir tree? Concolor white fir (Abies concolor) is a stately evergreen tree with a symmetrical shape, long, soft needles and an attractive, silvery blue-green color. Concolor white fir is often planted as a striking focal point and is especially appreciated for its winter color. In rows, it creates an effective wind block or privacy screen.

Concolor White Fir Facts

Concolor white fir is native to the western United States, but it grows well across the country, in USDA plant hardiness zones 3 through 8. In other words, it tolerates very cold temperatures but doesn’t do well in hot southern climates. It isn’t a city tree and doesn’t tolerate pollution and other urban conditions.

Concolor fir is beautiful in open areas where the graceful, drooping lower branches have space to touch the ground. You can prune the lower branches if you want to grow the tree near a sidewalk or driveway, but doing so may ruin the natural form of the tree.

Growing White Fir Trees

Concolor white fir grows in either full sunlight or partial shade. It tolerates nearly any type of well-drained soil, including loam, sand or acidic soil. However, clay may present a problem. If your soil is clay-based, work in plenty of compost or other organic matter to improve drainage.

Water concolor white fir regularly during the first year. Thereafter, give the tree an occasional soaking during hot, dry weather. Water the tree thoroughly before the ground freezes in late autumn.

Apply 2 to 4 inches (5-10 cm.) of mulch around the tree to control weeds, conserve soil moisture and prevent temperature extremes.

Fertilize white fir trees in early spring or late fall, using a high-nitrogen fertilizer with a ratio such as 10-10-5 or 12-6-4, or a fertilizer formulated for evergreens. Dig the fertilizer into the soil around the tree, then water well. Large trees generally require no fertilizer, but you can always dig a bit of well-rotted manure or compost into soil.

Prune white fir, if needed, before new growth emerges in spring. Study the tree carefully, then prune lightly to maintain the tree’s natural shape.

White fir isn’t usually injured by serious pests, but scale and aphids can be bothersome. Kill overwintering pests by spraying the tree with dormant oil before new growth appears in spring.

Spider mites may be a problem in warm, dry climates and may cause older needles to take on a yellowish cast. Spraying the tree weekly with a strong stream of water generally dislodges the tiny pests. Be sure the water reaches the middle of the tree.

Healthy white fir trees are rarely damaged by disease.

White fir

White fir (Abies concolor) photo: John Hagstrom

Tree & Plant Care

Do not plant in heavy clay soil.
Fir trees need very little pruning, but if pruning is needed do it in spring.

Disease, pests, and problems

No serious problems.

Disease, pest, and problem resistance

Tolerant of heat as well as cold temperatures.

Native geographic location and habitat

Found in mountainous areas in the southwestern United States.

Bark color and texture

Bark is gray.
On young trees the bark is relatively smooth; older trees are irregularly furrowed into broad flat ridges.

Leaf or needle arrangement, size, shape, texture, and color

Evergreen needles are flat and attached singly to the stems. They are 2 inches long and curve outward and upward on branches.
Color is blue-green.

Flower arrangement, shape, and size

Flowers are inconspicuous.
Male pollen cones are red to red-purple; female flower cones are rose red and found in the upper portion of the tree.

Fruit, cone, nut, and seed descriptions

Cones are erect and cylindrical; 4 to 5 inches long.
Color is pale green turning purplish as they mature.

Cultivars and their differences

Blue Cloak white fir: (Abies concolor ‘Blue Cloak’): This cultivar has powder-blue needles that hang down.

Candicans white fir (Abies concolor ‘Candicans’): A cultivar with intensely silver-blue needles.

Glenmore white fir: (Abies concolor ‘Glenmore’): A more compact tree (30 feet high) with longer, blue-gray needles.

Wintergold white fir: (Abies concolor ‘Wintergold’): Needles are yellow in winter and spring, turning dark green in summer.

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