Oak wilt, caused by a fungus Ceratocystis fagacearum, is responsible for killing large numbers of oaks annually in Minnesota. The greatest concentrations of oak wilt are in and adjacent to the seven-county metropolitan area surrounding Minneapolis and St. Paul. Red and white oak trees can be preventively treated for oak wilt with a root flare infusion of fungicide. Call Majestic for a free estimate.

Because of the risk associated with overland spread by insects, Majestic Tree care does not prune oak trees in the spring or summer. Instead, we will schedule maintenance pruning of your oaks in the "safe" period between the months of November and March.

• High Risk Period. April, May and June: don't wound or prune! If trees are accidentally wounded or pruning is unavoidable, cover the wounds immediately-within minutes-with one of the preferred materials such as water-based paint or shellac.

Symptoms of the disease Red oaks, such as Northern Red Oak and Northern Pin Oak, are highly susceptible to infection by the oak wilt fungus. White oaks range in susceptibility and once infected die slowly, a branch at a time, often surviving for many years. Red and white oaks can be treated preventively, before any signs of the disease are present. Only white oaks can be treated therapeutically (some disease present) to delay or halt further spread of the disease. Oak wilt is easily identified in red oaks by the rapid wilting of affected trees. After symptoms first appear, a red oak will generally wilt completely in two to six weeks. The trees wilt from the top of the crown down and individual leaves wilt from leaf tip and margins to the bases, turning bronze to brown. Fallen leaves are often green at the base. Leaf discoloration of affected white oaks resembles autumn colors. Photo credits: http://www.extension.umn.edu/distribution/naturalresources/ DD3174.html

Diseased trees primarily spread the fungus to nearby oaks through grafted roots. If oaks on or adjacent to your property already show signs of the disease their root systems must be severed to prevent transmission through root grafts. Oak Wilt Root Trenching In high value white oaks, systemic fungicide injection can prevent infection of trees adjacent to oak wilt affected ones. Treatment of white oaks exhibiting early symptoms of oak wilt (less than 30% of crown affected) can also prevent further disease development for at least 2 years. Treatments for oak wilt are now available in generic brands. Majestic transfers that savings to you. If you prefer using the name brand, we will provide a proposal that honors your request. Call Majestic for a free estimate. Majestic Tree Care certified applicators inject treatments safely in accordance with MN Department of Agriculture certification requirements.