Once they bloom, they generally are done blooming for the year. Is it really hot where you at right now? The misting system is probably not getting any water to the roots really. Have you poked down inside around it to see if water is actually down to the roots? I don't like auto water systems personally. I like to hand water so I can control what each plant gets, there is no waste that way and some plants like more water than others. This bush will eventually get large and a mist system will probably not be enough.
