Hi- first-time poster and happy to join the community! Would someone help me to identify what might be wrong with my tree? It started suddenly losing leaves about 2-3 weeks ago. Also noticed this morning, that few leaves are rotting and stuck together.

It is a Chinese Elm and it is inside. It needs to be outside. The rocks do not help, The tree is lacking in light and air. It is possible that there are insects on leaves that are sticking together, leaves do not rot on a tree unless it is dead.

Thank you so much for the prompt response. It is normally outside in the open sun. We are in California, so it gets plenty of exposure. I just brought it into the shade to take pictures. I do suspect insects, as we have a lemon tree close by on the same balcony and I noticed larvae on some of the leaves. Any suggestions on how to treat this elm tree?