Leaf scorch is a common problem for maple trees. Symptoms are light brown or tan dead areas between the leaf veins or edges. It’s a sign of several potential issues. Dry weather, mixed with wind and heat is the primary cause. Lack of water will also cause them to scorch. If the soil is dry, the scorching can be undone with appropriate watering. Soil contamination is another culprit. Salt stemming from treated winter roads, the build-up of fluorides in potting soils, or fertilizers that are high in phosphate can all cause scorching. Last but not least it could be a reaction to a fungal or bacterial vascular pathogen.
Prevention and treatments vary depending on the root cause. Some are more common than others. Spraying specific fungicides, making sure to rake all fallen leaves so nothing can fester are common practices to minimize leaf scorch.
Insects present their own set of problems. Whether it’s aphids and their sticky eating habits, the seemingly legless and immobile Scales, the unsightly but harmless Gall Makers, or the Asian Ambrosia Beetles. The latter makes it seem as if your maple is growing toothpicks out of its trunk – it’s a very serious issue for the health of the tree. Introducing natural enemies such as ladybugs, parasitic wasps, and insecticides are all common treatments for most insect issues.
Read more from Clemson University at: https://hgic.clemson.edu/factsheet/maple-diseases-insect-pests/