Michigan State University Extension
Ornamental Plants plus Version 2.0 - 00000938
01/01/98
Hardiness Zones: 4 to 8 (some cultivars may be hardier) Habit: Varies from shrub-like to 30-foot trees with rounded, upright or weeping forms. Type: deciduous tree or shrub Annual Growth Rate: 12 to 18 inches Flowers: White, red, pink, and single or double Fruit: Red, yellow, orange or blush combinations of these
Comments: Crab Apple flowers in the spring, the showy blossoms make their appearance before the lilacs bloom. Although the actual time of bloom will vary from year to year, depending on temperature, a total bloom period of up to four weeks can be expected. Very-early blooming Crab Apples may flower as early as the Star Magnolia, while late bloomers may coincide with the Black Locust. The bloom period of an individual cultivar may vary from two days to almost two weeks depending on weather conditions.
Crab Apple buds may be pink, white or red, and open blossoms may be white to dark purplish red, with many variations in between. Most Crab Apples have single flowers, but a few have semi-double or double blossoms.
Some cultivars bloom heavily only every other year. Avoid these alternate-bearing trees. The majority of Crab Apple cultivars produce consistent flower displays each year.
Foliage Most Crab Apples have attractive green foliage. Some have a distinct reddish or bronze leaf color for the first month or so of the growing season. Most Crab Apple cultivars do not have especially attractive fall colors.
Fruits A flowering Crab Apple is defined as any apple (genus Malus)with fruit 2 inches or less in diameter. The color of the 1/4- to 2-inch fruits ranges from bright red to purple and bright yellow to orange, with intermediate shades and combinations. Fruits of some cultivars begin to color in August, while the fruits of others do not reach their true color until September or October.
The fruits of some cultivars ripen and drop by the end of August, but the fruits of others may still be present in the spring. Cultivars with fruits persisting into winter can add a good deal of color to the early winter landscape. Birds may eat these fruits in winter and early spring.
Fruits follow the flowers, so alternate-bearing cultivars will fruit heavily only in those years when they produce many flowers.
Growth Habit Flowering Crab Apples can be less than 20 feet tall, but some may grow to 30 or 40 feet. Most Crab Apples are rounded and dense, but growth habit varies widely from narrowly upright to weeping. In summer, each form of Crab Apple lends a distinctive character to the landscape, and the twisted limbs of older specimens add a picturesque beauty to the winter scene. The various plant forms, flowers and fruit colors make Crab Apples a very useful species in the landscape.
Diseases Disease susceptibility or resistance should be given as much consideration as the ornamental traits when selecting a Crab Apple. Four diseases--apple scab, fire blight, cedar-apple rust and powdery mildew--are the major disease problems affecting Crab Apples.