Two well-known diseases
continue to be a threat in the City. Dutch elm disease and Oak wilt are
still infecting trees throughout the city.
Dutch Elm Disease
Dutch elm disease is a very common problem throughout the city each year. Tell-tale signs of the disease include “flagging,” where an entire branch of leaves will turn yellow and then brown creating a sort of “warning flag” in the tree canopy.
According to city ordinance, the property owner must remove infected trees within 20 days of notification by the city. The disease can be controlled through proper sanitation measures.
While not overly prevalent in Chanhassen, oak wilt has been diagnosed on several trees in throughout the city. Watch your oaks, particularly red and pin oaks, each summer for branches full of dead, brown leaves and/or a rapid decline in health.
Bur Oak Blight
Bur oak blight is often mistaken for oak wilt. This fungal disease only affects bur oaks, causing their leaves to form wedge-shaped dead areas, brown leaf veins, and dead leaves that persist through the winter.