How to Grow and Care for Silver Birch

Silver birch, also commonly known as European white birch, is a cool-climate deciduous tree with a distinctive stark white and exfoliating bark and light yellow catkins and foliage that gives it seasonal interest. Silver birch grows best in cooler conditions so it is not ideal for areas that suffer from high humidity and warm summers. The tree requires full morning sun, afternoon shade, moist, acidic soil, and temperatures that remain under 75 degrees Fahrenheit. The tree does not do well in hot, dry, or humid climates.

Silver Birch Tree Care

Here are the main care requirements for growing silver birch:

• Choose a site with morning sun and some afternoon shade.
• Grow in moist, well-drained, preferably acidic, sandy, or rocky loam.
• Water so the soil is constantly damp but the tree will tolerate some dry soil. Its root zones prefer to be covered by snow in the winter.
  

Light

To enjoy the silver birch's brilliant yellow foliage at its best, it is important to consider light when planting. The birch’s aversion to heat makes it necessary for the tree to get full sun in the morning and partial shade in the afternoon.

Soil

Betula pendula enjoy moist, well-drained sandy loams. Acidic soil is preferred, but it is a versatile tree and will adapt to many conditions.

Water

The silver birch should have constantly moist soil. If not in a suitably wet location and an irrigation system is not available, consider a soaker hose to mimic the wet, snow-covered, or damp forest floors of northern Europe. Mulching the silver birch will help to conserve moisture in drier regions.

Temperature and Humidity

The plant does best in cool climates where it does not get warmer than 75 degrees Fahrenheit and where snowy, wet winters are the norm.

Birches do not thrive in heat and humidity. The tree grows best in zones 2 to 7 and is short-lived in warmer zones 8 and 9, though it is not recommended to plant in those areas south of zone 7. 

Fertilizer

Silver birch is adept at growing well in many different soil types and will take to soil that is not particularly fertile. No supplemental fertilizer should be needed unless you desire more blooms.

Types of Silver Birch

There are many cultivars of silver birch available depending on what form, color, sterility, and heat tolerance you are looking for. Some of the most popular cultivars of Betula pendula are listed below:

• ‘Filigree Lace’: Dwarf form of the silver birch with an intricate cut-leafed pattern; grows to 7 feet tall and 3 feet wide
• ‘Laciniata’: Has a very serrated cut leaf pattern; rows 25 to 30 feet tall and 15-30 feet wide
• ‘Purpurea’: New foliage is reddish-purple; very susceptible to pests and cannot withstand infestation
• ‘Youngii’: An extreme weeping form growing 10 to 12 feet tall

Pruning

The silver birch does not need much, if any, pruning. If you do need to prune, do so in the dormant season which should be early winter (November or December). Be aware that you should avoid pruning in the late winter or spring because that is when the bronze birch borer is active. The pest may be attracted to the open cuts in the tree that are oozing sap.

Propagating Silver Birch

Propagating any type of birch tree with branch cuttings is tricky and the success rate is much lower than if you germinate the tree's seeds. If you choose to propagate a silver birch tree through a cutting, take these steps in the late spring or early summer:

1. Cut a 6- to 8-inch-long green branch tip, cutting just below a leaf node, using a sterilized garden snipper. Remove all the leaves from the bottom half of the cutting and keep one set of leaves at the top.
2. Dip the cutting in rooting hormone and then plant it in a small pot filled with standard potting soil.
3. Cover the pot with a loose clear plastic bag. Put the pot in a bright spot but not in direct sunlight.
4. Keep the soil moist but not soggy.
5. In eight weeks, roots should develop at which point you can transplant the rooted cutting into the ground.

How to Grow Grow Silver Birch From Seed

It is much easier to propagate a silver birch tree using seeds that it is to use cuttings. Collect birch seeds in the fall through winter, when the catkins brown. The seeds are small, with wings that help them fly in the breeze. Here's what to do:

1. Place the tiny, winged seeds in a small container filled with compost or humus.
2. Cover the seeds with a thin layer of potting soil and sprinkle them with water.
3. Place the container in an area where the seeds can stratify, such as in a refrigerator or an unheated garage during winter, where they can stay cold for six months.
4. After six months, put the container in a sunny spot and keep the soil moist.
5. Seeds should sprout in a few weeks. Find the strongest, healthiest seedling that can be planted in the ground in the spring after the last frost has passed.

Overwintering

There are a few measures of extra precaution you can take to overwinter a silver birch tree. Before mulching for the winter, water the root zone heavily. However, you may need to water the area if you have a winter drought or no snowfall. If you are concerned about trunk health or sun scorch, wrap the lower trunk in tree wrap.

Note that the thin bark may exfoliate during winter months to reveal various colors. This is a normal process and there is no need to help the tree by peeling more bark.

Common Pests & Plant Diseases

White birch is most harmed by the bronze birch borer, which will kill the tree. Signs to watch for that may indicate the borer include sparse foliage and branch dieback starting at the canopy, trunks with oddly shaped markings, raised lumps on the bark, and sawdust tunnels viewed on the peeled-back bark. Infestations may be controlled with insecticide sprays to kill adults in mid-May to mid-June.

Other pests include aphids and birch leafminers, both of which will cease leaf discoloration and leaf fall. A small aphid infestation can be dislodged by sharp sprays of water on the leaves but insecticides may be necessary for heavy infestations that could turn fatal if not managed. Birch leafminers can be annoying but not deadly to the tree. A tree specialist may be able to help with prevention through chemical means that will cause minimal damage to the tree.

Fungal diseases to watch for include leaf spot and various types of trunk cankers, which both affect unhealthy trees. There is no true prevention or cure for leaf spot or canker other than maintaining a healthy, wound-free tree. For leaf spot, apply a fungicide in the spring of the next year to help eliminate the issue.

How to Get Silver Birch to Bloom

Bloom Months

Catkins appear on silver birch trees from March through April and bloom around May through June, depending on conditions.

What Do Silver Birch Flowers Look and Smell Like?

The flowers on a birch tree are called catkins. A catkin is a few inches long and has clusters of tiny yellowish-brown flowers covering the caterpillar-like shape.

Silver birch trees have both male and female catkins on the tree. Male catkins are the long, droopy yellow forms. The female catkins are the newer, smaller bright green shoots that are more upright in form. The tree itself has a faint sweet, woodsy fragrance even if the catkins do not directly produce a smell.

How to Encourage More Blooms

Drought and dry conditions will impact the amount of blooms your silver birch will develop. Keep the tree hydrated in all very dry weather to encourage more catkins. Feeding the tree liquid fertilizer in the spring can help, too.

Common Problems With Silver Birch

The silver birch is easy to maintain given the right moist, cool conditions. However, there are a couple of issues to contend with when it comes to growing this tree in your yard.

Browning Leaves

A silver birch with large brown blotches on leaves may be infested with aphids or birch leafminers. Leaf spot is the other culprit, which requires pruning of affected branches.

Fruit Drop

The catkins that drape from the silver birch tree are attractive, but these will drop along with the fruit, causing a mess under the canopy.

Low Canopy

The low-hanging canopy itself causes an issue that can be a concern to some, too. Not much grows beneath it because the weeping form blocks much of the light from under the tree. Try to plant shade-loving ground coverings or shade grasses that may do well under the canopy.

Soil Erosion

Slopes surrounding the area under the silver birch are prone to soil erosion due to lack of ground cover unless the situation is mediated with the correct plantings.