Sycamore trees are large trees that can reach up to 90 feet in height, and you can easily recognise them by their characteristic peeling bark. The sycamore does have specific diseases and pests that attack it, leaving behind identifiable symptoms. To find out if a sycamore tree is sick, you must examine the tree closely.
Look for sores, also called cankers, that encircle large branches or are at the base of leaf clusters. If you find sores, examine the leaves carefully for brown spots and check to see if the new leaves are falling off before they unfurl. Check for these symptoms in the early spring. Though often confused with frost damage, these symptoms are indicative of sycamore anthracnose.
Check the ground for leaf drop when it is not appropriate, such as midsummer or during the spring. Examine the twigs and branches of the tree for circular patches of white mildew. Sycamores are especially susceptible to white mildew if they are located in a humid, shady area.
Check the leaves and branches for signs of insect infestation. Paths eaten out of the leaves, holes bored into the bark and weeping sap are all signs of insect infestation.
Monitor the height of the tree and the length of the branches. Branch dieback and stunted growth are signs of illness in a sycamore tree. You should also consider any other unexpected changes in the tree's appearance as a potential sign of disease or insect infestation.