Yellow with Red Dahlia Dahlias at the Mendocino Gardens were a   pleasant surprise for us this year. We visited in August on the way home from San Francisco. The Dahlia garden had just opened and was magnificent. There are many types that begin to bloom at the end of the summer season. The pompom and ball varieties are particularly interesting in color and shape. We will place the lavender (or chocolate), yellow, yellow/red, and red balls in square frames in series. Striking.