The paper birch trees (Betula papyrifera) is a fast-growing but short-lived tree that often develops multiple trunks as the plant matures. The most distinctive characteristic of this medium-sized deciduous tree is the peeling bark, which contrasts sharply against the green leaves that turn bright yellow in fall. The peeling white bark blends well with winter's snowy surroundings. Historically, this was the birch tree used by Native Americans to construct birch-bark canoes—hence the alternative common name, "canoe birch."
The leaves of this tree grow 2 to 4 inches long with double-toothed margins. The small dry fruit (nutlets) form in clusters on drooping catkins that turn brown upon maturity. The paper birch, being a monoecious tree, bears both male and female catkins. Similar to most other birch trees, the paper birch likes a moist environment, making it the perfect accompaniment to a stream or pond feature in your yard.
Like most trees, the paper birch is usually planted in the spring, when nurseries generally have a good stock of potted or balled-and-burlap specimens. This is a fast-growing tree, adding 12 to 24 inches of growth per year. However, it rarely lives more than 30 years.
|Botanical Name||Betula papyrifera|
|Common Names||Paper birch, American white birch, canoe birch|
|Plant Type||Deciduous tree|
|Mature Size||50 to 70 feet tall; 25- to 50-foot spread|
|Sun Exposure||Part shade|
|Soil Type||Sandy or rocky loam, medium-moisture to wet|
|Soil pH||5.0 to 7.5 (acidic to neutral)|
|Bloom Time||March to April|
|Flower Color||Yellowish brown (male trees) or green (female)|
|Hardiness Zones||2 to 7 (USDA)|
|Native Area||Northern North America|
How to Grow a Paper Birch Tree
Birches, in general, are well known as water-loving trees and are not very drought resistant. It is best planted in an area that is naturally moist and will require a lot of watering if planted in dry soils or in areas where it must compete with other plants. Do not plant paper birch in compacted soil or in climates that have intense periods of heat.
Paper birch grows best if you can cover the ground beneath its canopy with a thick layer of mulch to keep the soil moist and cool. Rather than planting lawn grass right up to the trunk, a mulch island around the tree is a good idea.
You will need to be on guard for pest problems with this tree, as some can be quite devastating. And be prepared to remove older trees, as this species is not long-lived.
Paper birch prefers the part-shade conditions found along margins where other taller trees are growing, but it can grow acceptably if planted in full sun, especially in cooler climates.
Paper birch grows best in a sandy or rocky loam soil that is fairly moist. It naturally favors acidic soil but will do fine in soil with a neutral pH, or even slightly alkaline.
Preferring moist soil, this tree will need to be watered frequently if planted in a lawn location where it must compete with turfgrass. It will require less watering if planted alongside a stream, pond, or bog where conditions are naturally moist.
Temperature and Humidity
This tree grows best in cooler climates and cool soil temperatures. Keeping the soil cool and moist by heavy mulching is a good strategy for trees that can't be planted in a naturally moist location. Near the southern end of the hardiness range (zones 6 and 7), this tree sometimes struggles; it prefers a climate with long winters and coolish summers.
A spring feeding routine with a slow-release granular fertilizer mixed into the soil beneath a layer of organic mulch will help the paper birch resist bronze birch borers. But avoid excessive feeding.
Pruning a Paper Birch Tree
Paper birch may form one or several trunks. Once a central leader has been identified, you can prune the tree to favor a singular trunk. Other than the occasional shaping, paper birch does not need much pruning. Do not prune in late winter or early spring or your tree will bleed sap in an attempt to heal the wound. While sap bleeding is not necessarily detrimental to the tree's health, it can cause an unsightly mess, and excessive open wounds can make the tree susceptible to pests.
Propagating a Paper Birch Tree
Although the success rate is usually only about 50 percent, birch trees can sometimes be propagated by rooting branch cuttings. Cut a 6- to 8-inch-long green branch tip, making the cut just below a leaf node. Remove all the leaves from the bottom 3 inches of the cutting. Dip the cutting in rooting hormone, then plant it in a small pot filled with standard potting soil.
Cover the planting pot loosely with a clear plastic bag and place it in a bright location but out of direct sunlight. Keep the soil moist but not soggy for about eight weeks, until roots develop.
Transplant the rooted cutting into the desired landscape location, into a hole where the soil has been amended with peat moss and sand. Be careful not to break the young roots as you transplant the cutting into the ground.
Keep the soil moist but not soggy for the next eight weeks. At this point, if the planted cutting is developing new growth, you know that a successful tree is beginning to grow. The growing sapling can now be fed with diluted fertilizer.
Common Pests/ Diseases
Birch trees in general are not great choices for urban environments where pollution is present, but they can do well in suburban landscapes.
All birches can fall victim to the bronze birch borer, a devastating insect pest. An affected tree will show yellowing leaves that begin to shed, and the tips of the branches will turn brown. These symptoms generally start at the top of the tree and move downward. Paper birch is one of the more resistant of the birch species, but if bronze birch borer does strike your tree, prune off affected limbs as you see them, and use a pesticide designed to control the insects. Badly affected trees will need to be removed and replaced. (You can consider replacing it with a river birch (B. nigra), which is more resistant to bronze birch borer.)
Aphids, birch skeletonizers, and birch leaf miners can also wreak havoc on trees that have become weakened due to water stress. So, make sure your trees are not competing with your lawn for moisture. Another potential drought problem is birch dieback, where the branches of the birch tree die out over time. Conversely, trees that are watered too much can become prone to fungal problems, including leaf spots and cankers.
Large trees that begin to show die-back may have no disease at all—they may just be at the end of their lifespan. As a paper birch approaches 30 years, you can expect it to begin to decline and die.
Varieties of Paper Birch
The pure species, Betula papyrifera, is most commonly planted, but there are two cultivars that can be considered:
- 'Chickadee' has a narrower, pyramidal shape and is somewhat more resistant to bronze birch borer than the pure species tree.
- 'Snowy' is an especially fast-growing variety with a dazzling white bark. It also has good resistance to bronze birch borer.
Paper Birch vs. Other Birch Trees
Several other birch species can be alternative choices to paper birch:
- River birch (Betula nigra) has a similar growth habit to paper birch, but it has bark that peels dramatically in layers to reveal reddish-brown underlayers over bright white inner bark. It is a good choice in regions where bronze birch bore is a severe problem. This species has a better tolerance for heat, but it shouldn't be planted north of zone 4.
- Silver (weeping) birch (Betula pendula or B. verrucosa) is a single-trunk birch with pendulous, hanging branches, rated for zones 2 to 6. It has good heat resistance and is sometimes planted as far south as zones 7 and 8.
- Gray birch (Betula populifolia) grows in a multi-stem cluster and is similar in stature to the paper birch. Suitable for USDA zones 3 to 6, it has a better tolerance for dry soil than most birches.
- Himalayan birch (Betula utilis) is a handsome broad-spreading tree with a 25- to 30-foot canopy. It is a good choice where you want a more horizontal variety that provides more shade. This attractive specimen tree can be grown in zones 4 to 8, but like most birches, it performs better in the northern end of that range.
Paper birch is an airy tree that provides dappled rather than dense shade. It is a fast grower—growing up to 24 inches per year—and can be used for areas of your yard where you need to create an impact quickly.
Paper birch mixes will with evergreen trees and is a good choice where you want bright fall color. It can also be used as a specimen tree, but be prepared to remove and replace a tree that has reached full-size maturity, as the species does not live long once full size is reached.
The creamy peeling bark of paper birch provides great fall and winter interest. In the classic application in large landscapes, paper birches are planted in small clumps of three or more located close to a water feature
Paper birch trees are a good choice for homeowners who are also animal lovers. Luna moth caterpillars are fond of the paper birch, and the tree also attracts birds such as yellow-bellied sapsuckers, black-capped chickadees, tree sparrows, and pine siskins.