How long before Paperbark Birch trunks turn white?
One of the prettiest trees in our landscapes are undoubtedly White Birch. Their incredible white bark lights up the landscape throughout the seasons, especially if the trunks are uplighted at night to draw even more attention to their glowing white trunks.
But how long does it take the trunks of a typical Paper Bark White Birch tree Betula papyrifera to turn from the cinnamon brown colour present in immature trees into the outstanding white papery bark we are all so familiar with in the landscape?
The answer to that question may vary to some degree depending on the age of the tree purchased from the nursery, the location the tree is planted and the amount of water and, to a lesser degree, the soil conditions where it is growing.
In a typical, store-bought clump or single-stem White Birch tree that is small enough to carry home in the back of your hatchback wagon or truck, you can expect at least a 3- to 4-year wait before the trunks begin to turn white. If you purchase a more mature tree that is already beginning to show signs of whitish-orange bark, expect a year or maybe two before the reddish-brown bark with its horizontal slits (lenticels) gives way to a reddish orange bark and eventually is peeled off enough to reveal the white paper bark.
Very immature trees that are purchased as “whips” may take up to ten years before you are blessed with solid white birch bark.
The white birch bark of this clump shows how far along the three main trunks are in comparison to the much younger fourth trunk still in its reddish-brown phase. This fourth trunk is probably 2-3 years away from taking on its all-white trunk. The solar-powered uplighting on the white trunks creates a real mood in the evenings.
How quickly do Birch trees grow?
Birch trees are considered relatively fast growers where they are happy. On a good year, expect anywhere from 13 inches to more than 24 inches (or two feet) a year for your average White Birch tree or clump. The paper birch grows to a height of between 50’-70’ with a spread of around 35’ when mature. The River Birch enjoys a similar growth habit.
This image illustrates the peeling bark of another one of our clump birches that is just entering its pure white phase. The cinnamon bark on the left is just beginning to reveal the white bark. It’s noteworthy that this clump is just 9 or 10 feet from the clump shown above that is much further along in its transformation from reddish brown to white.
Should I plant a birch tree in my urban landscape?
The white birch is a medium-sized tree that is very common in urban landscapes despite its relatively short-lived existence under these more difficult conditions.
Birch trees are generally unable to handle excessive heat and humidity which are often exacerbated in urban landscapes where they are planted near asphalt driveways or close to homes where they are unable to get proper air flow to keep them cooler.
These urban trees and others living in zones 6 and up may live only about 30 years – even less if they are under extreme stress.
It’s a good idea to keep this in mind when planning a landscape in urban areas. Birch trees cannot be counted on to live long lives and may have to be removed leaving a large hole just when your landscape has matured nicely and is looking its best. On the other hand, if you have a very sunny area, say for example in a new subdivision, a fast-growing birch tree will bring relief from the hot sun and provide a beautiful specimen for years to come. A good idea might be to plant a small, slower-growing oak or maple tree nearby which will slowly take over once the birch tree begins to decline.
At some point, you could even cut down the birch tree to make room for the larger, more long-lived native oak or maple.
In the wild, or in a more rural location or woodland-type garden, the white birch is often able to survive longer and grow to heights of between 50 and 70 feet. A typical trunk measures about 1 to 2 feet wide. Trees in colder climates, however, can even live for more than 100 years.
The leaves of the white birch are ovate and the catkins (male and female flowers) can grow up to 4 inches long. The female catkins form cylindrical cones that disintegrate when ripe, spreading the seeds which are eaten by many birds and small mammals including chickadees, redpolls, voles and ruffed grouse.
By uplighting the Birch clumps, you can appreciate their white trunks both day and night.
For more on Birch Trees in the Woodland garden check out my other articles:
On our property, we have two areas with birch trees: a grouping of three narrow weeping purple birch in the front that were purchased as very young whips, and three clump birches planted in the back yard that together have at least ten main trunks combined.
Our final clump of birch trees planted at the same time as the other two clumps, is significantly behind the other clumps in growth and maturity despite being purchased and planted at the same time. This clump, although already in the ground for four years, is still a year or two away from obtaining their white trunks.
The three young whips (Betula pendula ‘Purpurea’ )planted in the front took several years to begin displaying their white trunks. After maybe ten years of growth they have matured into a lovely grouping of weeping birch trees. These trees are slow-growing and upright as young trees, that eventually begin to weep more with age, and sport bronze-purple leaves and silver-grey bark.
The clump birches in the backyard are further along after only about 3-4 years in the ground. To give you an idea about the original size of the clumps, they were all purchased from a big-box store and taken home in the back of our Subaru Outback wagon. Although the containers were quite large, I was able to get all three into the back of the wagon to transport them home. (This helps to give readers an idea of the trees’ original size.)
Our three clump birches in the back were all planted at the same time and within about six feet to 10 feet of one another to create a small birch grove. They are, however, taking on their magnificent white trunks at significantly different rates. This tells me that the amount of sun, water and quality of soil they receive have obviously also played a role in how quickly the trees take on their papery-white trunks.
Birch trees are early colonizers after a fire or natural disaster so they prefer to grow in open sunny areas and will not do well in shade. Our clump that is the slowest to mature is also the clump that gets the least amount of sun. The other two clumps block much of the sun from the third clump.
The trees also require plenty of water, so mulching around the tree roots to retain moisture is a good idea.
Recent hot, dry spells have stressed our birch trees in the backyard to the point where their leaves are beginning to turn yellow and dropping off a little earlier than I would like. Deep watering is required, especially prior to winter to keep the trees hydrated.
(Go here, for my article explaining early leaf drop of birch trees.)
A male cardinal hanging out in a birch tree just beginning to get its white bark.
Why is the bark white?
Studies have shown that the white bark of birch trees serves it well when it comes to regulating the tree’s internal temperature, especially in the more northern climates where the trees tend to live much longer.
The white bark is known to reflect the sun’s heat away from the tree during cold spells, which helps to protect the tree’s vital cambium layer just beneath the bark.
If the Birch’s bark were the more typical dark colour found in other trees, the life-giving liquid that travels up and down the tree’s trunk through the cambium layer would be constantly fluctuating between freezing and thawing, which would eventually weaken and kill the tree. The reflective qualities of the white birch bark helps to regulate the temperature and allow the trees to survive during extreme weather conditions.
This trait is likely to play an important role in the tree’s survival as climate change continues to play havoc with our more northern growing zones.