Lynda Ellis, UM Extension Master Gardener in Anoka County, May 25, 2014.
A flowering crab apple is one of the most beautiful trees in the spring, and comes in many different habits, heights and leaf, bud, and flower colors. The fragrance of apple blossoms is a sure sign of spring. The blossoms also provide necessary food for bees. It can serve as a pollinator for other apple trees. Their smaller size makes them perfect for our landscapes and most fit nicely under power lines.
However, some varieties have less-desirable attributes. The hopa variety, widely planted in Minnesota a generation ago, is susceptible apple scab and many other diseases. It also drops its 1” fruit in summer, which creates the mess so many people remember. The majority of newer varieties are grafted onto dwarf root stock to limit their size, and have persistent fruit. By spring, the tiny remaining apples have shriveled to the size of a raisin and are not a problem when they drop to the ground. The examples described below have 0.5” or smaller persistent fruit and are resistant to apple scab, fire blight, cedar-apple rust, and powdery mildew. Mature size is given as height x width.
Coralburst has a compact rounded habit; is 12’ x 15’; has pink flowers and sparse fruit.
David has a compact rounded habit; is 12’ x 12’; has pink flower buds, white flowers, and red fruit; it blooms and fruits heavily in alternate years.
Indian Magic has an upright, spreading habit; is 15’ x 15’; has deep pink flowers and red-orange fruit.
Indian Summer has a rounded habit; is 18’ x 18’; has rose red flower, bright red fruit, bronze-green leaves in spring, and good orange-red fall color.
Louisa has an umbrella-shaped weeping habit; is 12’ x 12’; has a pink flower; yellow 0.375” fruit.
Molten Lava has a weeping habit; is 12’ x 15’; has white flowers, abundant bright red fruit, and yellow bark.
Prairiefire has a spreading rounded habit; is 20’ x 20’; has red flower buds, purple red flowers, purple-red fruit, and good orange-red fall color.
Robinson has an upright-spreading habit; is 25’ x 25’; has deep pink flowers, dark red fruit, fast growth, and bronze-green leaves. It is not suitable under power lines.
Sargent has spreading shrubby habit; is 8’ x 12’; has white flowers, dark red 0.25” fruit, and profuse fragrant flowers and fruit, often in alternate years. Its fruit is especially attractive to birds.
These are only a sample of what is available. Pick your desired size, habit, flower color, and other attributes. You will have an attractive addition to your landscape, winter hardy and suitable for most any soil. For more information, see “Flowering Crab Apple Trees” from Colorado Extension
http://www.ext.colostate.edu/pubs/garden/07424.html and “Managing Apple Scab” from Minnesota Extension http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/managing-apple-scab/.