I'm wondering if any of you may know why a deciduous tree would still be holding on to it's leaves?
I have a young Eastern Redbud (Cercis canadensis), and it has not defoliated. It was still looking very lush and green, up until last week when we were hit with freezing temps. Now, of course the leaves have been bit, and are yellow, and hanging limp…but still hanging on.

Any ideas?

Your tree did not ready itself for winter properly. It may be because its genetics is from a northern provenance (like Michigan) or perhaps you just had an unusual fall that did not trigger the internal winter changes in the tree early enough. The fact that the leaves are yellow, and did not freeze green is a good sign. It's likely there will be no consequential damage, although only time will tell.

You say the tree is young. Some juvenile trees tend to hold leaves much longer into the fall/winter than what is "normal" for an older tree. Usually this trait lasts for only a few years. I am not sure if Redbud exhibits this phenomenon or not.

Thanks so much, Rick! We did seem to have a very brief, and fairly warm Fall. Almost like we went from Summer into Winter overnight!

Yes, the tree is young. As a matter of fact, I found it growing in a flower bed about 6 or 7 years ago. Apparently planted by a squirrel or bird. It was just about 6" tall when I found it, and dug it up, put it into a pot, and kept it in a container until this last year, when I found a spot in the yard for it. Maybe the phenomenon that you spoke of is true to Redbud's as well. We'll wait and see.

Since posting my question, most of the leaves have fallen…It did seem quite strange that the leaves changed from green to yellow overnight…The same night that it was hit by the freeze. Your right only time will tell if it suffered any damage. I'll be keeping my fingers crossed in hopes that it didn't!