Introduction

A hybrid of Malus baccata and Malus seiboldii, redbud crabapple grows at a moderate rate to 25 feet tall and 15 feet wide (can grow 30 feet wide), creating a dense, pyramidal form with weeping branch tips. True to its name, the blossoms of redbud crabapple start out as red buds in spring which open to soft pink flowers, eventually fading to white. These blooms are delightfully fragrant and open in spring before the new leaves appear. The small, shiny, bright orange/red fruits that follow, persist on the tree well into the winter, if not first eaten by birds.

General Information

Scientific name: Malus x zumi

Pronunciation: MAY-lus x ZOO-mee

Common name(s): Redbud crabapple, 'Calocarpa' zumi crabapple

Family: Rosaceae

USDA hardiness zones: 4A through 8A (Fig. 2)

Origin: not native to North America

Invasive potential: little invasive potential

Uses: espalier; street without sidewalk; tree lawn 3-4 feet wide; tree lawn 4-6 feet wide; tree lawn > 6 ft wide; deck or patio; trained as a standard; container or planter; parking lot island > 200 sq ft; parking lot island 100-200 sq ft; parking lot island < 100 sq ft; highway median

Availability: not native to North America

Description

Height: 20 to 25 feet

Spread: 15 to 30 feet

Crown uniformity: irregular

Crown shape: spreading

Crown density: dense

Growth rate: moderate

Texture: medium

Foliage

Leaf arrangement: alternate (Fig. 3)

Leaf type: simple

Leaf margin: serrate, serrulate, crenate

Leaf shape: elliptic (oval)

Leaf venation: pinnate, brachidodrome

Leaf type and persistence: deciduous

Leaf blade length: 2 to 4 inches

Leaf color: green

Fall color: yellow

Fall characteristic: not showy

Flower

Flower color: white/cream/gray, pink

Flower characteristics: very showy

Fruit

Fruit shape: round

Fruit length: less than .5 inch

Fruit covering: fleshy

Fruit color: red, orange

Fruit characteristics: attracts birds; showy; fruit/leaves not a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; not showy; typically multi-trunked; thorns

Pruning requirement: needed for strong structure

Breakage: resistant

Current year twig color: brown

Current year twig thickness: thin, medium

Wood specific gravity: unknown

Culture

Light requirement: full sun

Soil tolerances: clay; sand; loam; acidic; alkaline; well-drained; occasionally wet

Drought tolerance: moderate

Aerosol salt tolerance: low

Other

Roots: not a problem

Winter interest: yes

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

This has been described as one of the best crabapples for street tree planting. When specifying trees for street or parking lot planting, be sure to order single trunked trees with major branches located as high on the trunk as possible. This will reduce the need to prune off lower limbs to provide clearance for vehicles and pedestrians. However, branches will still need to be removed as the tree grows older due to the slightly drooping habit of the tree. Suckers from the root system may also need to be occasionally removed. Trees planted away from walks and streets can be pruned and trained any way you like. They often look nice with branches left to the ground, forming a solid, thick, mounding shape with age.

Redbud crabapple should be grown in full sun on well-drained, acid soil. They are adapted to a variety of soils, including clays. It is recommended that you purchase trees propagated on their own roots.

Pests

No pests are of major concern. Aphids can usually be found infesting a variety of crabapples, including this one. Control of pests is usually not needed.

Diseases

Although resistant to scab, redbud crabapple is susceptible to fireblight and mildew.