Betula 'Royal Frost'
Common Name: birch
Type: Tree
Family: Betulaceae
Zone: 3 to 6
Height: 30.00 to 40.00 feet
Spread: 15.00 to 20.00 feet
Bloom Time: April
Bloom Description: Green
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: High
Suggested Use: Naturalize, Rain Garden
Flower: Showy
Leaf: Colorful, Good Fall
Other: Winter Interest
Tolerate: Deer

Culture

Best grown in moist, acidic, sandy or rocky, well-drained loams in full sun to part shade. Best foliage color occurs in full sun, but plants appreciate some afternoon part shade in hot summer areas such as St. Louis. This tree needs consistently moist soils. Consider using soaker hoses and bark mulches to keep the root zones cool and moist. It needs little pruning, but if necessary, prune during the dormant season. Avoid pruning in spring when the sap is running because it will bleed. Performs best in cool northern climates where summer temperatures rarely exceed 75 degrees F. and where root zones are generally covered with snow throughout the winter.

Noteworthy Characteristics

Betula is a genus of about 60 species of deciduous trees and shrubs found throughout the northern hemisphere. Many are excellent garden and landscape trees.

Genus name is the Latin name for birch.

‘Royal Frost’ is an upright pyramidal birch featuring burgundy-red to purple foliage, showy yellow-orange to red fall color and attractive white bark. It typically matures over time to 30-40' tall and to 15-20' wide. It is the result of a cross between Betula populifolia 'Whitespire' (white bark) and Betula 'Crimson Frost' (purple foliage). Tiny monoecious flowers appear in early spring (March-April) in separate catkins on the same tree. Greenish female flowers are followed by drooping cone-like fruits containing numerous small winged seeds that typically mature in late summer.

Problems

This cultivar performs best in cool summer climates. It is not recommended for planting south of USDA Zone 7. Weakened birches, including those stressed by summer heat and humidity, become more vulnerable to the bronze birch borer which infects and kills trees. Aphids, leaf miner and birch skeletonizer may occur. Watch for leaf spot problems.

Garden Uses

This purple-leaved birch is best grown as a specimen or accent. It may struggle in the St. Louis climate.