TAR SPOT ON OXFORD MAPLE TREES

Tar spot is a tree disease that I see often as an applicator in Oxford, MI. Tar spot is one of the easier tree diseases to diagnose, as it leaves black circular spots on the leaves of a maple. They are called “tar spots” because the fungus looks like tar has been dropped on your leaves. For the most part this tree disease is a cosmetic problem.

I’ve never seen a tree in Oxford die from a tar spot infection, however a bad infection will cause almost every Maple leaf to be covered with large black spots, and it also can cause the leaves to drop early. Once your tree has tar spot it is going to be on the leaves for the rest of the summer. To reduce the chance of infection next year make sure to rake up as many of the infected leaves as possible. The infected leaves are what carry this tree disease from one year to the next.

The best way to control tar spot in is to schedule a tree spraying program in the spring. A tar spot control program would consist of us coming out and making sure the tree disease is indeed tar spot, then you would be put on a regular tree spraying program to have that tree or trees treated. The treatment would involve spraying the tree with fungicides; this will prevent the disease from forming on the leaf.

The fact that Tar Spot does not hurt the tree means a lot of homeowners in Oxford do not spray their trees for this particular tree disease. The problem with not treating tar spot is soon it spreads to all your neighbors trees; it does not take long for tar spot to affect an entire block. What I don’t like about tar spot is that maples are one of the most beautiful trees and known for its leaf, and tar spot makes them very ugly.

Apple Scab

What is apple scab? Apple scab is a disease to Malus trees (apple and crabapple trees). This disease is caused by the ascomycete fungus Venturia inaequalis. I know you are thinking...WHAT? When we think of apple scab in Michigan we think of an apple that has the brownish black dents in them or the crabapples that look bare and sickly by mid-July. But, apple scab is much more than this. Apple scab can affect tree leaves, buds or fruits. This disease is not a serious threat to these plants. However, if the tree is infected numerous times it may become very weak and become more susceptible to other insect or disease pests.

Apple Scab is dependent on cool, wet weather and infects tree leaves in the spring. In the late summer to early fall, apple scab infections can produce secondary spores and create new infections which will continue to infect the tree during wet periods. Wind and rain carry apple scab spores from infected leaves to new growth on nearby trees where new infections begin.

Owen Tree Service offers fungicide treatments to ensure your trees will be protected from apple scab. If you think you may have an apple scab problem give Owen Tree Service a call. Fungicide treatments are applied as new leaves are developing in the early spring. These treatments are started in April and continue through early June to ensure your chance of having apple scab is minimal. Apple scab not only ruins perfectly good apples it also takes away the beauty of your ornamental crabapple trees. When crabapple leaves start turning a dingy brown, black color it’s hard to admire the beauty of these ornamental trees. We spend tons of money making sure our yards, trees, and plants look stunning, so why take the chance of having your crabapple trees bare for half of the summer.