KC Gardens

Heritage River Birch question

Maybe you can give some advice, I have 2 Heritage River Birch trees that I planted 12 years ago, they are around 45 feet tall. The trees were doing great, with no signs of any problems. As of today, there are no leaves on either tree, a third heritage river birch about 60 feet away looks great with plenty of leaves. I scraped a few branches and found green, which makes me think the trees are alive, but the lack of leaves has me wondering. A lace bark elm thats close by and all the ground cover around the birch trees is doing well. Any advice would be appreciated, is it possible that the trees could suddenly be dead? I am in Cincinnati Ohio. - Mark -