Tree care professionals, woodland owners, and urban natural resource managers are greatly concerned with managing oak wilt across Minnesota. Oak wilt is responsible for killing large numbers of oaks annually across the state. A recent confirmation of oak wilt in Morrison County near Little Falls makes it the most northwestern find in Minnesota. Researchers and forest health specialists from the US Forest […]
A new publication from the US Forest Service-Northeastern Area, State and Private Forestry can help forestry professionals, homeowners, and others identify common diseases to oak trees in the Midwest. How to recognize common diseases of oaks in the Midwest: a quick guide discusses the common diseases of oaks and associated tree symptoms and presents excellent illustrations of the diagnostic features […]
Tuesday, March 24th from noon to 1:00pm *Note change in date. Oak wilt is old news but still newsworthy. This destructive invasive’s range does not yet extend over half of Minnesota’s land with highly susceptible species. Bur oak blight is relatively new news. Its extent nearly covers Minnesota. Learn all about these diseases, including how to differentiate the two. […]
Q. What is oak wilt? Oak wilt is a fungal disease that kills thousands of oak trees every year. Oak wilt spreads in two ways: Through root grafts between similar species, radiating outward from a central infected tree; and over land, carried by oak sap beetles carrying fungal spores from tree to tree. Q. What are the “risk season” references? […]
Passing along an announcement from the Minnesota DNR, Division of Forestry: Greetings from MN DNR Forest Health! The March 2009 issue of the Forest Insect & Disease Newsletter, focusing on invasive species, is now available at http://files.dnr.state.mn.us/publications/fid/fid_march09.pdf Highlights include: Firewood Restriction Law Emerald ash borer: FAQ Emerald Ash Borer Preparedness Plan in development Gypsy moth treatments planned Sirex woodwasp update […]
Foliage diseases my cause conifer needles to turn yellow or brown or drop prematurely. Hardwood leaves may develop yellow, brown, or black spots. These diseases weaken trees by reducing the ability of leaves to produce plant food.
Forest health is affected by insect outbreaks, diseases, invasive species, regeneration, fire ecology, natural disturbance, and many other factors. Not all insects and diseases are bad. Native insects and diseases are a normal part of a healthy forest. An example is the periodic defoliation events from forest tent caterpillars (sometimes called armyworms). Minnesota forests evolved in the presence of these bugs, […]