Picea Glauca
White spruce trees go by many different names. They may be heard of casually as Canadian spruce, skunk spruce, cat spruce, Black Hills spruce (because of their successful ranges in the Black Hills of South Dakota), western white spruce, Alberta white spruce, or Porsild spruce.
Though these trees are some of the slowest growing of the spruce family, they are capable of growing in the harshest and most extreme climates. White spruces that exist in the Northwest Territories of Canada can survive temperatures of -69 degrees Fahrenheit. Though they may only be about 8 meters tall, some of them are said to be over 300 years old.
One of the absolute hardiest conifers on the planet, this evergreen tree is the provincial tree of Manitoba and the state tree of South Dakota. They’re most well known as Christmas trees, as a great windbreak tree, and for their important place in the ecology of boreal forests in North America.
Curious about other types of trees? Head on over to 101 Types of Trees! We also have more detailed descriptions of both Red Spruce Trees and Black Spruce Trees for your interest!
What do White Spruce Trees Look Like?
Root System
Spruce trees will most commonly grow shallow and laterally wide-spreading root systems. Though their root systems may develop differently depending on the growing location. Their root systems are variable because the tree is so incredibly adaptable.
Based on the types of growing conditions that red spruces are subjected to, they are more likely to develop shallow and wide roots (plate root systems) because they are very easily damaged by windthrow.
They are also susceptible to acid rain, and will sometimes develop taproots in order to help combat this. This is a way in which they can access moisture reserves deep in the soil, so they are less exposed to the damages of acid rain.
Dimensions
Because of the extreme locations in which they live, white spruce trees can be truly any height. In its most northern locations, it may only grow to be about 10 meters tall. In regions with less harsh winters, they can be between 15 and 30 meters, and there are some exceptional trees that can exceed 40 meters in height!
Also dependent on their heights, their trunk diameter will vary as well. Though usually lingering around 1 meter in trunk diameter, that will obviously be wider or more narrow if they have extreme heights.
Growth Pattern
The branches of the white spruce tree have a vertical accent. They grow horizontally with an upward sweep near the end. This growth pattern creates a very narrow, conic crown in young trees, and it becomes more of a cylindrical shape in mature trees. Lower branches are thicker and longer, and upper branches are thinner and shorter.
Bark
White spruce bark will be either a darker grey-brown color or a lighter ash-brown color. The bark is very thoughtful and scaly, and flakes off in moderately sized plates.
Foliage
The shoots of white spruce tree are a pale brown color, and will be hairless if on the eastern side of the continent, or pubescent if they are growing in the western range.
The leaves of the white spruce tree are needle-like. They are longer, and they have a diamond shape in the cross-section. Needles are blue-green in color and can remain on the tree for up to 8 years.
How do White Spruce Trees Reproduce?
Cones
Spruce trees are monoecious, meaning that both female cones and male cones will occur on the same tree. This does not mean that they are able to self-pollinate. This is usually avoided, to ensure that future trees have genetic diversity, which will make them a more resilient tree species.
Seed cones (ovule producing, female characteristics) are a glossy red/green color. They are slender and cylindrical in shape and have stiff scales. Scales will open upon maturity in order to receive pollen.
Pollen cones (pollen-producing, male characteristics) are the same color and shape. Spruce cones will produce pollen in the early spring, and the pollen is dispersed by wind.
Once a white spruce cone has reached full maturity (which usually occurs 4-8 months after pollination) it will be between 1 and 3 inches long, and be a pale brown color.
Seeds
Once pollen is dispersed, the female cone will close its scales in order to germinate and produce seedlings. The seed cone will droop down once it is mature (usually in summer or early autumn), which will make for easier seed dispersal.
Seeds are tiny and black and are attached to a pale brown single wing, which will help the seeds populate farther reaching areas. The cone will only open and disperse seeds if the weather is exceptionally dry. Sometimes cones will close up again if there is an unexpected rain. Dispersal occurs throughout the fall and winter, and sometimes even into the next growing season.
Sexual Maturity
There are some white spruces that will start producing seeds as early as 4 years, though this is surprising considering their slow growth. It is more common for them to become sexually mature around 10-15. Their most productive crop years will occur around the age of 30 and beyond.
What Are Some Other Types of Spruce Tree?
Black Spruce (Picea mariana)
Black spruce trees are native to many parts of the United States and Canada. They are the official provincial tree of Newfoundland and Labrador. They are a small species with upright branches and the smallest cones. They are commonly used for cultivars in parks and gardens.
Blue Spruce (Picea pungens)
The blue spruce tree is native to western North America, specifically in places like Wyoming, Colorado, and New Mexico. They are also sometimes called green spruce, Colorado spruce, or Colorado blue spruce. They are medium-sized with horizontal leaves, and the sharpest leaves.
Norway Spruce (Picea abies)
Norway spruce trees are native to northern, eastern, and central Europe. They have branches that hang down, and they have the largest cones of any of the tree species. They are commonly planted for their use of wood and as Christmas trees.
Red Spruce (Picea rubens)
Red spruce trees are native to eastern North America. They are a medium-sized tree that grows in warmer climates than other spruce species. They are characterized by their red-tinged inner bark.
Sitka Spruce (Picea sitchensis)
Sitka spruces are the tallest of all spruce tree species, and it is the 5th tallest tree of all conifers. They grow to be an average of 100 meters tall, and a trunk diameter of 5 meters. They are native to the western parts of the United States and Canada.
Where do White Spruce Trees Grow?
White spruces are native to the most northern temperate boreal forest of North America. They occur in boreal, subalpine, montane, and great lake areas. They occur in USDA hardiness zone 3 through 7. They grow as “shelterbelts”, meaning that they usually grow on the outskirts of forests because they can handle harsh winds.
They were originally native to Alaska and throughout Canada, though they have now been naturalized into the northern parts of the United States as well. They occur naturally throughout Montana, Minnesota, Wisconsin, Michigan, Vermont, New Hampshire, and Maine.
Growing in the absolute most severe winters known in North America, they tend to grow alongside black spruces, birch trees, and aspens. They perform particularly well with a dense understory of feather moss.
What are the Growing Conditions of Red Spruce Trees?
Soil
White spruce trees can live in a variety of soil types, though their prosperity is highly dependent on the properties of the soil. Its fertility and mean temperature will determine whether or not a tree can survive. They prefer soils of glacial and lacustrine origin and have good drought tolerance.
Temperature
White spruce trees cannot perform well at all in warm climates, and will only grow in areas that have very cold winters.
Sun Exposure
In their youth, white spruce trees are very shade tolerant. They can survive for up to 50 years as an understory tree. Once the competing hardwoods die, they will sprout up very quickly and become the dominant species of hardwood.
If they spend their entire lives in open areas with full sun exposure, they will experience much faster and consistent growth.
What are the Damaging Agents to the White Spruce?
Insect Pests
Spruce trees have a common enemy, and that is the spruce beetle. An invasive species that is most prevalent in cold regions, they have destroyed upwards of 2,300,000 acres of spruce forests in Alaska alone.
They are also attacked by the spruce budworm, which is a parasitic insect. Unfortunately, the white spruce is the most susceptible to the spruce budworm than any other spruce species. Spruces are also susceptible to damage from canker, gall formers, aphids, leaf miners, leaf rollers, spider mites, weevils, borers, and pitch moths.
Acid Rain
Spruce trees are particularly vulnerable to the effects of acid rain. Acid rain is largely due to climate change. Acid rain changes the chemical composition of soils and their nutrients. This toxic rain will decrease the amount of calcium in the soil, and increase the amount of aluminum.
This is damaging because calcium is very important for spruce trees for physiological processes. These processes are helpful for their cold tolerance, disease resistance, signal transduction, and cell wall synthesis.
Calcium is also a very useful resource for the red spruce population to engage in dark respiration, wherein they are able to still respirate and photosynthesize once the sun has set. Aluminum also interferes with the roots’ ability to absorb nutrients.
How are White Spruce Trees Used?
Wood
White spruce wood is even textured with a straight grain. It is a creamy white color with a hint of yellow.
White spruce wood isn’t used for aesthetic purposes, though is very important in the lumber, pulpwood, and millwork industries.
Ornamental
When they aren’t being used as ornamental trees or as landscape plants in gardens and parks, white spruces are also a popular choice of Christmas trees. They are quite slow-growing, and so they are not as popular as balsam fir trees for Christmas trees.
Landscape spruces are commonly planted as shelterbelts to help protect more vulnerable plant life.
Wildlife
Deer, rabbits, ruffed grouse, red squirrel, snowshoe hare, birds, and other small mammal species heavily browse white spruce seeds. The white spruce forest also makes for an important habitat for small animals, and for moose and deer to help protect them from deep snow.
FAQs
Is a white spruce tree a gymnosperm?
Gymnosperms are essentially naked seeds. This means that they do not have a protective capsule or layer that needs special treatment in order to germinate. White spruce tree seeds have a paper capsule to help with wind dispersal, though it does not prevent them from immediate germination.
How fast do white spruce trees grow?
White spruce trees are the absolute slowest growing on the spruce species, and will barely grow more than 6 inches within a year.
How tall do white spruce trees get?
Because of the extreme locations in which they live, white spruce trees can be truly a height. In its most northern locations, it may only grow to be about 10 meters tall. In regions with less harsh winters, they can be between 15 and 30 meters, and there are some exceptional trees that can exceed 40 meters in height!
Also dependent on their heights, their trunk diameter will vary as well. Though usually lingering around 1 meter in trunk diameter, that will obviously be wider or more narrow if they have extreme heights.
How long do white spruce trees live?
White spruce trees have an average life expectancy of between 200 and 300 years, though there are some exceptional trees that are over 400 years old.
How do you identify white spruce?
White spruce trees can be identified by their bark and their needle type. Their bark is an ashy gray color that peels off in the scales. They have longer needles that are a blueish green color, and have 4 sides, making it more difficult to roll it in your finger. Needles also grow as individuals directly from a twig, rather than in clusters.
How do you prune a young white spruce tree?
It is important to avoid pruning trees in the wintertime, as they will consistently seep sap from the cut wound and create a large mess. It is best to reserve pruning for the summer or spring before they develop new foliage.
How long does it take for a white spruce to grow into a Christmas tree size?
It can take as many as 10 years for a white spruce to become an acceptably sized Christmas tree. This is a very big reason why they are not a popular option for Christmas tree farms. They are in huge competition with balsam fir trees which grow much, much faster.
How far apart should white spruce trees be planted?
Spruce trees can be planted quite close together, as little as a meter. Their root systems are compatible with one another. This makes spruce trees a great landscaping tree, as they can create dense and protective hedges.
Are white spruce trees deer resistant?
White spruce trees are naturally deer resistant.
What is the difference between white spruce and a Norway spruce?
The Norway spruce is a much taller species of spruce, that has larger cones and drooping branches. The white spruce is shorter with upward ascending branches and smaller cones with bluish-green needles.
What is the difference between white spruce and red spruce?
The red spruce is a medium-sized species of spruce, with yellow-green needles, glossy cones, and hairy twigs. The white spruce is a short species with blue-green needles, brown cones, and hairless twigs.
What is the difference between white spruce and black spruce?
Black spruce and white spruce are very similar, though the black spruce has darker bark. Additionally, black spruce trees have tiny hairs on their twigs, and shorter needles, whereas the white spruce is hairless with longer needles and bluish-green foliage.
What is the difference between white spruce and blue spruce?
Blue spruce trees have needles that are more blue than green, and their needles are shorter but are extremely stiff and sharp. White spruces have needles that are more green than blue, with long needles that are more flexible and soft.
Are spruce trees fast-growing?
Depending on the species of a spruce tree, they can vary in growth speeds. White spruce trees are the slowest growing and smallest, whereas Sitka spruce trees are the fastest growing and the largest (upwards of 100 meters!).
Do moose eat white spruce?
Moose are relatively uninterested in spruce trees unless they are protecting them from deep snow and snowstorms.
What is the difference between a spruce tree and a pine tree?
Spruce trees have needles that grow individually on a twig, are much shorter and stiffer. Pine tree needles grow in clusters, are far longer and more flexible.
Do spruce trees grow in shade?
In their youth, white spruce trees are very shade tolerant. They can survive for up to 50 years as an understory tree. Once the competing hardwoods die, they will sprout up very quickly and become the dominant species of hardwood.
If they spend their entire lives in open areas with full sun exposure, they will experience much faster and consistent growth.
What is weeping white spruce?
Weeping white spruce trees are a cultivar of spruce that is characterized by soft, limp twigs. This texture gives the tree a very bent crown with pendulous branches. They are referred so scientifically as Picea glauca ‘pendula’.