I have one of 3 remaining Dutch Elm trees in my yard. The leaves look healthy on branches. However on the trunk there are sapplings sprouting and on those leaves are small raised bumps. See photo. Should I be concerned?
The growths on the leaves look like leaf galls. The galls are not harmful to the tree and does not need to be controlled. See our website for photos and more information http://extension.umd.edu/hgic/shade-tree-galls
We recommend that you prune off the water sprouts from the trunk. This can be common on elms.