Question about Pruning

I've spent days weeding my gardens. After all the rain and heat we've had the gardens are growing like crazy--including the weeds. Today I and my helper are pruning the Bridal Wreath bushes that frame the backside of my sign. But, I have a question. If I stop pruning the shoots at the top of the five foot bushes will they eventually drape and produce flowers? My hope is to not have to prune them. Any advice?