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. 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.
Light
Paper birch prefers the partial 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.
Soil
Paper birch grows best in 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.
Water
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.
Fertilizing
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. For the amount to use, follow the product label instructions. Avoid excessive feeding.
Types of Paper Birch Tree
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 the 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 the bronze birch borer.
Pruning
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. The tree tends to shed smaller branches on its own. Their attachment to the main trunk is so weak, you often don’t have to prune off dead limbs—they just fall off when they are ready. 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. Here’s how:
How to Grow Paper Birch Trees From Seed
Collect paper birch seeds in the fall, when the catkins start to brown. The seeds are small, with wings that help them fly on the breeze. Place the seeds in a small container filled with compost or humus. Cover the seeds with a thin layer of potting soil and sprinkle them with water. Place the container in an area where the seeds can stratify, such as in a refrigerator or an unheated garage during winter. They need to be in the cold for six months. After the six months is over, set the container on a sunny windowsill for light and warmth. The soil should be kept moist. The seeds should sprout within a few weeks. Thin out the seedlings until you have one strong contender. This can be planted in the ground in the spring after all danger of frost has passed.
Overwintering
A good layer of mulch underneath the tree will help it through the winter. Also, keep an eye on the water the tree is getting. Snowfall can often give a tree what it needs during the winter, but if you are facing a period of little to no snow, additional watering can help keep the ground moist.
Common Pests and Plant Diseases
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. Aphids, birch skeletonizers, and birch leaf miners can also wreak havoc on trees that have become weakened due to drought. 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.
