Question From: NEBRASKA
Q: My thornless hawthorn tree has small white balls at the base of leaf stems and is weeping sap from these sites. It also has a blackish bark.
The white balls may be galls. If this were my tree I would get an onsite inspection from a trained professional, a certified arborist. To find one in your area go to www.tcia.org and enter you zip code. Another option is to take samples of the leaves and photos of the bark to an independent garden center or nursery that sells these trees.