Lawn Renovation - Common Diseases and Pests

Apple scab: Apple scab is a common disease of apple and crabapple trees causing spots and lesions on the foliage and fruit, often resulting in early defoliation of the tree. The disease is more prevalent following wet spring weather. Some varieties of trees are naturally resistant to the disease while other varieties are extremely susceptible. Fungicide treatments applied to susceptible trees can greatly reduce infection.

Spider mites: Spider mite injury is caused from the mite mouthparts damaging the plant cells in order to ingest the sap. Mite feeding can cause stippling patterns on the leaves, resulting in a gray or bronze appearance to the plant. Common insecticides are often ineffective in controlling mites, and in some cases can increase the mite population. Special miticides and proper cultural practices are required to keep mites under control.

Japanese beetles: Japanese beetles are the adult stage of the Japanese beetle grubs that feed on turf plants. Adult beetles are active from mid to late summer and will feed on over 200 varieties of plants. Insecticide treatments applied to susceptible plant material will reduce feeding damage. Beetle traps are not generally recommended as the traps tend to attract more beetle than they actually capture.

Bagworms: Bagworms are commonly found on evergreen plants such as arborvitae, spruce, and juniper, but will also attack many deciduous plants as well. The larvae construct the "bag" from silk and bits of plant material, and will carry this bag with them as they feed. When disturbed, the larvae retreat inside the bag for protection. Hand picking or insecticide treatments during the summer feeding season will provide the best control.

Root girdling: Synthetic twine and burlap, wire baskets, and natural root malformation can cause disruption in the sap flow of the tree. This problem often develops several years after a tree was planted and the trunk and roots have grown in diameter to a point where a constriction of the sap conducting vessels occurs, resulting in the decline of the plant.