Dark StarA form of the California lilac, 'Dark Star' makes a dense, vase shaped plant 6 ft tall x 8 ft. wide in 8 10 years. Vary dark green leaves are quite small and have a dimpled surface. When the dark, cobalt blue flower clusters bloom in spring, the overall effect is breathtaking. This plant requires little or no water in summer. Often used as a feature shrub or informal screen and is best suited for coastal gardens, as it is only hardy to 15 deg F.