I'm in the clay. I let one sit in a pot for awhile before I planted it. It flowered nicely the next year and in addition via seeds or runners or something, I ended up with several others where the pot had sat. I transplanted a couple of those and they bloomed the year before and after transplant and of course the ones that stayed in placed bloomed really well. I'm not a native here. Perhaps if you're in the sand rather than clay, that is holding it back?

dogridge, is it possible that in the area of where you planted the redbud that there was a previous black walnut tree?
The roots of a black walnut, one even cut down, will continue to have a negative effect on the growing of many other plants/shrubs and trees.

I've read they won't bloom if in to much shade.

Like anything, probably needs sufficient sun. Try a native one.