Trees, Shrubs and Conifers: Help with a flowering cherry, 0 by DrDoolotz

DrDoolotz wrote:
Last spring (2005) I purchased a flowering cherry tree. It flowered and had nice leaves on it but looked a bit sparse. I chalked that up to first year settling in. Then, in about August, all the leaves turned yellow and fell off. I was a bit unhappy and thought it might not make it through the winter, but it had lots of buds, so I hoped. This spring, it flowered beautifully, and came out into leaf. However, it had quite a few branches that didn't flower. I trimmed those off. Now, it is only June 6, and the leaves are yellowing and falling off. There are no visible bugs on it, although some tiny holes on some leaves, but nothing serious. I do have good close-up vision, so if there was anything there, I would see it. I post a picture here of what it looks like overall, and then I'll post some shots of the leaves close up. If anyone has any suggestions of what may be wrong or what I can do, please advise.

Urbandale has pretty heavy clay soil but I dug it out well and did some amending when I planted it with some better soil and peat, mixed with the clay.

Here it is (poor thing) looking sort of sad.