Sycamore tree has not leafed yet and the one next To it is fully leafed out
Can there be something wrong with one of my sycamore trees, one is fully leafedcout the other has a few tiny buds but no leafs as of yet. All teees around us are all leafy, I checked for fungus but looks healthy- these two trees are next to eachother
Determining if there is an issue with a tree-due to slow leaf out can be a difficult task.
Cut into a bud-is it brown and dead inside or alive?
Test the branches; do they snap off and break or bend?
Did all the branches bud out?
Failure to leaf out can be due to a disease, root rot or pests.
Cold weather can also effect the buds.
I would remove a few samples of branches and take to your County Extension Office for inspection.
Here are some links for you including a link to help you locate your nearest office.