This winter has proven to be harsh on many plants, but especially so on Sweet Gum Trees. While most plants might have some leaf burn or browning or some dieback, it appears the Sweet Gum trees may have taken a severe hit. So far across most of the state, it's being noted by various Extension Educators that those trees are not coming out of dormancy. These trees are considered to be native to Indiana, but even Indiana has different USDA Hardiness Zones. The Sweet Gum is considered a zone 5 plant, which should include our area. The lingering question is were we actually still too cold for those trees?
So if you have a tree that is not leafing out, what do you do? Unfortunately since this had not been noted as a problem in the past, the best advice is wait and see. If it does finally appear to leaf out, it may have actually survived and have been severely stunted this winter is all. If no new growth appears on the tree or it does not get at least a partial cover, you can assume the tree did not make the winter. I would wait no longer than mid-June to evaluate the response. By that time, it can be assumed if it was going to survive, it would be showing life by now.