Peggy Greb, USDA/ARS
Plant Common Name
Malus, the genus of apples and crabapples, is made up of about 35 species of deciduous trees and shrubs. They are native to the north temperate regions of Asia, Europe and North America and grown for their appealing, often edible, fruit and pretty fragrant flowers. In temperate regions apple trees are landscape and orchard essentials.
The branched crowns of these medium to small trees can be oval, rounded or spreading. The oval or elliptical leaves are thin, green and alternate on the stems. Some species even have lobed, fuzzy or purple-hued leaves and the edges of most have fine teeth. Fall color tends to be insignificant, but not for all.
The pretty fragrant five-petaled flowers appear in spring, sometime before the leaves. They are slightly cup-shaped and white, red or pink. The flowers are perfect, which means they have both male and female parts, though most require another apple tree nearby for cross-pollination. The main pollinators are bees.
The fleshy fruit is botanically known as a pome and may be very small or large. It has a thin skin, juicy flesh and a central core with five seeds enclosed in a papery capsule. Most are edible, though many are tough and woody, and all are ornamental. Fruits generally ripen late in the summer or fall.
Domesticated apples destined for the table have been cultivated for thousands of years. There are thousands of modern apple varieties and most are hybrids that are grafted onto rootstock. Apple rootstocks impart a wide range of benefits such as increased vigor, pest and disease resistance, and dwarfism, depending on the stock.
There are a number of notable crabapple species. The Japanese flowering crabapple (Malus floribunda) is a spreading tree with dark green leaves, pink flowers that are red in bud and produce very small yellow fruit. Malus ioensis, the prairie crabapple, is native to the central United States. It is a small tree with thorny branches, lobed leaves, showy white or pink flowers and small yellow-green fruit. The Zumi crabapple (Malus zumi) is planted for its abundant white fragrant spring blooms, small stature and loads of persistent shiny small red crabapples. Species such as these are parents to the hundreds of crabapple hybrids on the market.
Hardiness is species or cultivar dependent, but most need extended cold winters to flower and fruit. More specifically, they require hundreds of hours below 45 degrees Fahrenheit, but a few have been developed to require fewer than 200 hours. This requirement is called chilling hours and is specific to each type of Malus.
Most Malus prefer full sun and average to fertile well-drained soil. Though many are tolerant of drought, regular water is best for good flower and fruit production. There are many pests of Malus species, however there are also many selections bred to be resistant to the most devastating problems.
These trees are tops for great fruit and blooms. Spring would not be spring without apple blossoms or fall be quite the same without sweet crunchy apples to keep the doctor away.
Apple trees fruit best and acquire a better form with regular pruning. To learn more go to: http://www.ext.vt.edu/pubs/treefruit/422-021/422-021.html