Q.Problems With Dappled Willow
I planted a Dappled Willow last year and it was doing well. This spring, however, I noticed some of the leaves seem to be browning and/or drying out and there are full leaves at the ends of the branches but smaller leaves in the middle. I’m not sure if it needs more water/less water or it has some type of disease.
Certified GKH Gardening Expert
If you've had extreme rain recently, the plant could be waterlogged. Check it carefully for signs of insects or fungus. You'll need to watch for blight, fungus and invasive insects. Once you can identify any of these, it will be easier to know how to treat the plant. In the meantime, consider backing off a bit on watering and see if it perks up. Here's an article that outlines growing conditions:
https://www.gardeningknowhow.com/ornamental/trees/willow/dappled-japanese-willow.htm