Malus 'Louisa'
Common Name: flowering crabapple 
Type: Tree
Family: Rosaceae
Zone: 4 to 8
Height: 12.00 to 15.00 feet
Spread: 12.00 to 15.00 feet
Bloom Time: April
Bloom Description: Pink
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Flowering Tree
Flower: Showy
Attracts: Birds, Butterflies
Fruit: Showy, Edible
Other: Winter Interest
Tolerate: Air Pollution

Culture

Best grown in medium moisture, well-drained, acidic loams in full sun. Adapts to a wide range of soils. Established trees have some drought tolerance. Although some flowers may be lost, it is best to prune this tree as needed in late winter. Spring pruning should be avoided as it produces fresh, open cuts where fireblight bacterium can enter.

Noteworthy Characteristics

Malus is a genus of about 35 species of deciduous trees and shrubs from Europe, Asia and North America.

Genus name from Latin is an ancient name for apple.

‘Louisa’ is a weeping, pink-flowered crabapple tree that typically matures to 12-15’ tall and as wide. Branches typically cascade to and spread along the ground. Red buds open in spring (April in St. Louis) to single fragrant pink flowers (to 1 1/2" diameter). Flowers are attractive to bees. Flowers are followed by small lopsided crabapples (to 1/2” diameter) that mature in fall to yellow with a rose blush. Crabapples typically persist well into winter. Birds are attracted to the fruit. Glossy, ovate, dark green leaves (to 3” long) turn green-yellow-orange in fall, but fall color is usually not significant. Discovered by Polly Hill of Martha's Vineyard, Massachusetts in 1962.

Problems

The main diseases of crabapple are scab, fire blight, rusts, leaf spot and powdery mildew. Potential insect pests are of lesser concern and include tent caterpillars, aphids, Japanese beetles, borers and scale. Spider mites may occur.

‘Louisa’ has good disease resistance to the main diseases of crabapples.

Garden Uses

Plant as a specimen/accent or in small groups. General landscape use.