Should I prune our bleeding heart bush when it turns yellow? We planted it in a sunny area. It did amazing during spring but now looking very yellow and scorched.
You can prune it back if it's appearance is detracting from the area. Once the leaves start to turn the plant isn't going to be using them again.
Bleeding Hearts often go dormant during the summer, when this happens the leaves turn yellow and sometimes wilt away entirely. Even if the plant remains green until winter, next spring the Bleeding Heart will regrow from the ground up.
A sunny area might not be the best for a Bleeding Heart, in my experience they like partial shade and lots of water. However, with a good watering schedule you can probably keep it around.