Finally, Japanese red maples do not tolerate direct sunlight exposure, so leaf wilting could result from overexposure to sun. There are several possible insect problems with Japanese maples. Leaf spot disease rarely causes serious damage unless the Japanese maple is all ready diseased or damaged. The infected leaves may fall from the tree in severe infestations. Pseudomonas syringae is a common bacteria that affects many woody plants, including Japanese Maples. Irregular browning of leaf edges, especially those on the west side of the plant. At worst, they can cause the death of branches or even the tree itself by girdling the limb with their tunnels. Provide windbreaks with structures or strategically placed plantings to act as a baffle. While these Japanese maple pests can attack a tree of any age, they are usually found in young trees. If you fertilize your Japanese maple, use a slow-release fertilizer. A Japanese maple is a glorious specimen tree. In addition, apply a preventive fungicide spray to the Japanese maple at bud break. Once you can identify the disease attacking the Japanese maple, you can take the necessary actions to control and prevent it from returning. Some of these diseases are potentially deadly, while others are usually harmless and merely cosmetic. Brian Kunkel, University of Delaware, Bugwood.org, Maple Tree Bark Disease - Diseases On Maple Trunk And Bark, Tree Disease Identification: Sooty Canker Fungus, Japanese Maple Tree Lifespan: How Long Do Japanese Maples Live, Autumn Succulent Wreath – How To Make A Succulent Wreath For Fall, Mibuna Mustard Greens: How To Grow Mibuna Greens, Grateful Gardening: How To Show Garden Gratitude, What Is A Shrub Rose Bush: Learn About Different Shrub Roses, Grapefruit Tree Care – Tips For How To Grow Grapefruit, Thanksgiving Tradition: Turning Homegrown Pumpkins Into Pie, Growing Thanksgiving Dinner – Must Have Turkey Side Dishes, Interesting Uses For Pecans: What To Do With Pecans, The Bountiful Garden: Bringing The Garden To Thanksgiving. Aphids like fast growing plants. The most common Japanese maple diseases are caused by fungal infection. A strong spray of water and regular treatment with either chemical or organic pesticides will go a long way to prevent insect problems with Japanese maples. It is prevalent in moderate temperatures and shaded areas. Black, tar-like spots appearing on the leaves is a sure sign the Japanese maple is infected with anthracnose. Adjust watering, mulching, shading and other care practices and monitor the tree to see if it returns to normal health. You may also notice wilting leaves and gray, white or black growth on the tree itself. Japanese maple leaves can be spotted and the veins within the leaves can be blackened. © Copyright 2020 Hearst Communications, Inc. Leaves and small branches and shoots may also turn dark and die. Thankfully, prevention will help reduce the possibility of the fungus causing anthracnose attacking the Japanese maple. Milder cases can cause scarring. Rots are caused by the fungal pathogen phytophthora that attacks roots, collar and crown of the Japanese maple. Canker can attack through bark damage. So, this holiday season, we created a giving campaign for two of our favorite non-profits who are working to help put food on the tables of hungry families across the U.S. and around the world. Black, tar-like spots appearing on the leaves is a sure sign the Japanese maple is infected with anthracnose. Proper annual pruning, cleaning up of fallen leaves and twigs, and yearly replacement of mulch will help prevent the infection and spread of these Japanese maple tree diseases. As the fungus grows within the leaf, these areas develop into distinctive, slightly raised, shiny, tar-like, black spots on the leaves. Sign up for our newsletter. Verticillium wilt is another common Japanese maple disease. Verticillium wilt is another common Japanese maple disease. Japanese maples (Acer palmatum) are attractive trees producing green foliage that changes to vibrant hues of reddish purple, bronze and yellow. Flanigan has written for various publications, including WV Living and American Craft Council, and has published several eBooks on craft and garden-related subjects. Sap wood may also become discolored. When you spot damaged or diseased branches, remove and destroy them immediately. It causes leaves to twist, curl and distort. Again, mature Japanese maple trees will probably recover but young trees may not. If your Japanese Maple has leaf scorch, but the tree is still alive, there's most likely nothing to be too worried about. Look closely at the stems of the leaves and the base of the branches and even the trunk for small, black lesions and even brown or black streaks that are visible just under or even through the bark of the … The leaves eventually rot and fall. It sometimes affects only one side of the tree, leaving the other looking healthy and normal. One of the first things you may spot if your Japanese maple has a disease problem is an outbreak of small, round, red or purple spots on the leaves of the tree. Japanese maple trees are susceptible to diseases such as anthracnose, verticillium wilt, tar spot, leaf spot, leaf scorch and root rot. How to Care for Pieris Japonica Varieties, Clemson University Cooperative Extension: Maple, The Connecticut Agricultural Experiment Station: Common Diseases of Maple, University of California Integrated Pest Management Program: Powdery Mildew on Ornamentals, University of California Integrated Pest Management Program: Anthracnose, University of California Integrated Pest Management Program: Leaf Spot Diseases, How to Treat Apple Scabs on Red Flowering Crabapples, How to Get Rid of a Xanthomonas Leaf Spot on a Dieffenbachia.