Sweet alyssum has been a popular mainstay of summer gardens for decades, providing lightly scented masses of flowers that often cover the low mounds of green foliage. 'Snow Crystals' is a bright white, and fills the spaces of container planters while also spilling gently over the edge of hanging baskets. Excellent in rock gardens and other sunny locations, alyssum is drought tolerant once established, but will need more regular watering in container planters.