Ornamental crabapples (Malus spp.) make nice specimen trees, and produce beautiful flowers and fruits. Most are hardy to Zone 4, but disease resistance can be an issue. Depending on climate and other factors, many crabs are prone to attack from fire blight, scab, cedar-apple rust, and other diseases.
More than 400 crabapple cultivars exist in the U.S. nursery trade. Several researchers in various climates have evaluated crabs for disease resistance, including Hubert Conlon of the University of Tennessee Extension Service, Professor Edward R. Hasselkus of the University of Wisconsin, and Keith Warren, horticulturist at J. Frank Schmidt & Son Co., a wholesale nursery in Oregon.
The following five widely available ornamental crabapple cultivars were rated tops in disease resistance in all three research studies, so they should be good garden choices almost anywhere:
'Adirondack', 'Louisa', 'Prairifire', 'Red Jewel', and Malus x zumi calocarpa (which did show fire blight susceptibility in the Wisconsin study). Check with your county extension service for more cultivars suited for your location.
If you're a crabapple fan, hook up with the International Ornamental Crabapple Society. The IOCS has its own evaluation program at sites throughout the continent. Visit
www.malus.net