Cardinal shrub begins blooming in mid-May.  It blooms heavily for about 3½ weeks, and produces flowers here and there throughout the rest of the year.  This is a very large shrub and should be planted where it has room to grow.  Don't grow it in six feet of space like I did, or you will have to prune it hard each year to keep it tidy and natural looking.  Very few people correctly pronounce cardinal shrub's Latin name.  It is pronounced why-gee'-la.