Apple and crabapple trees in the Naperville area are infected with invasive fungi this summer at higher rates than usual. The cool, wet spring and summer have encouraged the growth and spread of common diseases, including cedar-apple rust. While this disease rarely kills, it can cause apple trees to lose leaves and make fruit deformed and inedible. Preventive measures can be taken to help assure it will not reappear next spring.
The first signs of the disease are yellow spots on leaves and fruit, usually in late spring. The spots grow and turn deeper orange with black spots. With time, leaves and fruit will drop off the tree, and fruit will be deformed. You may also see deformed gall growths on twigs.
The prolific disease is caused by the fungus Gymnosporangium juniperi-virginianae. It affects juniper, red cedar, apple and crabapple trees. The disease spreads only from the juniper or red cedar to the apple tree, not between junipers or apples. In optimal conditions, such as wet, cool weather, it can be carried as far as five miles away.
Junipers and Eastern red-cedar trees are native to the Chicago area. The Morton Arboretum, http://www.mortonarb.org/trees-plants/tree-plant-descriptions/eastern-red-cedar , tells us they are popular as landscape specimens, and are often chosen by municipalities for parks and city parkways, as they make good windbreaks, hedges and screens. Because of their popularity, it would be virtually impossible to completely eliminate the possibility of your apple tree being infected. However, it’s good to be aware of the disease as you choose trees for your own outdoor living space, and try not to place an apple tree too close to a juniper or red-cedar evergreen tree.
Apple and crabapple trees are some of the most popular fruit trees in the Naperville area, as they are beautiful to look at and hardy specimens. If you have an apple tree in your landscape, you will enjoy it for years with regular maintenance.
O’Donovan and Sons Landscaping in Naperville has a large selection of trees to enhance your outdoor space. For 46 years, we have been designing, installing and maintaining residential landscapes in Naperville and surrounding areas. Our landscape design team will work with you to plan the placement of your trees to bring you maximum enjoyment. Call us at 630-355-3370 to schedule an appointment!