I have two dissectum maples planted in the my yard. They have been planted in the same location for 9 years. This year we had a very harsh winter (multiple days below 30 degrees). The trees budded as normal in the spring and began to leaf out. Many of the leaves have not progressed beyond bud like formations or small fringe leafs, some leaves are of normal size. We also mulched the trees this spring with 3-4 inches of cypress mulch. They have never had mulch before this year. Is the mulch causing this issue? Should we remove the mulch? Any ideas what may be causing this issue? Thanks.