Answer: You didn't say how long your redbud has been planted. If it's very new to your garden, it's probably expending energy getting its roots established. Once it does that, you should see appreciable new growth. If it's been planted for over a year, it may just need feeding. Wait until spring, then fertilize lightly with a time released granualr fertilizer (in amounts as recommended on the package label). You should see new growth next spring.
Yes, heavy rains can retard plant growth by keeping the soil wet enough to cause stress. So if your redbud is established and you have already fed this past spring, heavy rains can account for poor growth.
Best wishes with your redbud!
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