Oak wilt – Please be aware!
Oak wilt (caused by the non-native fungus Ceratocystis fagacearum) is catching the attention of natural resource professionals and landowners across Michigan. In West and Northwest Michigan, oaks are amongst the most common and dominant species in many forests. Oak wilt is now wreaking havoc on our oak resource in Michigan, particularly those in the “red oak group” (those with leaves that have “pointed” tips, such as northern red oak, black oak, and northern pin oak). This fungus, which is related to the fungus that caused Dutch Elm Disease, kills oak trees by clogging its water transport system, thus causing the wilting of the leaves that is seen in infected trees. Once oak wilt has infected an oak tree, it can spread underground to neighboring oak trees via root grafts, and it can spread aboveground from sap-feeding beetles that carry the fungal spores to other trees. As oak wilt becomes more prevalent in Michigan, proper education about how to identify this disease and practices that can help slow the spread, will be necessary to help save the oaks that so many of us value.
So what can you do?
1) Learn how to identify which oak species are on your property. Oak wilt mainly infects oaks in the “red oak group”, and this includes trees that are otherwise perfectly healthy. Oaks in the “white oak group” can be infected but they are typically resistant.
2) Pay close attention to your “red oak group” trees. If you see the leaves suddenly turn a yellow or bronze color AND drop from the tree, then contact a professional who is qualified to determine if you have oak wilt. This changing of leaves and shedding of the leaves typically happens from mid-summer to early autumn, and the progression is very sudden.
3) There are other diseases and pests that affect and kill oak trees so please contact a qualified professional if you are not sure.
4) DO NOT cut or prune your oak trees from April to August as these wounds can attract the sap-feeding beetles that spread oak wilt. If pruning or cutting is absolutely necessary during this period, please make sure that you apply a tree dressing compound to the wound immediately following cutting. ALSO, do not move infected oak firewood!
For an excellent bulletin about oak wilt with more details, written by Michigan State University Extension, please go to http://msue.anr.msu.edu/resources/oak_wilt_in_michigans_forests
If your property is in Manistee, Mason, or the western half of Lake County and you think you may have oak wilt or would like more information about this disease, contact Josh Shields, Forestry Assistance Program (FAP) forester with the Manistee and Mason-Lake Conservation Districts, at 231-889-9666 (Office Phone), 989-220-9236 (Mobile Phone), or via email at firstname.lastname@example.org.