Crabapples ( Malus, spp.) are a versatile and popular small tree for urban and suburban landscapes. More than 400 species and varieties of crabapple are available which represent a diversity of flowering and fruiting characteristics, growth forms, and pest resistance. Flowers, produced in early spring are white, pink, or red. Fruit varies in size and colour, and may cling to twigs in winter to provide interest and food for wildlife. Crown shape may be rounded, upright, spreading, or weeping depending on variety. Dwarf crabapples are popular in containers where space is limited.
Culture for Crab Apple
Crabapples grow in moderately fertile, moist, but well drained soil in full sun, although partial shade is tolerated. Purple leaved forms colour best in full sun.
Concerns about Crab Apple
Crabapples are host to many insect pests to include caterpillars, aphids, scale insects, and spider mites. Fireblight is the most devastating disease of crabapple. Caused by a bacterium which infects through the blooms, fireblight causes branch dieback and death of susceptible varieties. Foliage diseases such as scab, rust, and mildew can cause defoliation. While crabapple tends to tolerate these diseases, defoliation detracts from their appearance and vitality. Disease resistant varieties are available and should be used to reduce the impact of these diseases.
Management Practices for Crab Apple
The key to successful pest and disease management of crab apples are early i.e. mid April to late May sprays of insecticides and/or fungicides. Three sprays need to be applied. Commencing sprays in June will produce little control. Fertilise in autumn or spring if deficiency symptoms were evident during the growing season.