History of shade tree disease control program and disease statistics

Minnetonka’s shade tree disease control program began in 1974, when Dutch elm disease (DED) that had infected and killed millions of elms east of the Mississippi River began to appear in Minnesota. In 1974 a total of 25 oaks and 26 elms were lost to disease in Minnetonka. In the peak year, 1978, Dutch elm disease killed 8,339 elms and oak wilt claimed 244 red oaks.

Currently, an average of 2,000 elms and 75 red oaks are identified as diseased and marked for removal city-wide each year. From June to September, on average, the city forester and 2-3 seasonal tree inspectors complete over 1,500 initial tree inspections on public and private property in order to identify elms with DED and oaks with oak wilt. Every site is rechecked for compliance after the property owner’s deadline lapses. Each private property owner is notified with a door hanger when their property has met the city’s guidelines for disease control. Tree inspectors make approximately 3,200 total site visits during the growing season.