Hoary Vervain is a drought tolerant perennial that boasts a long bloom time, often adding gorgeous purple flower spikes for up to six weeks in the late summer. This native variety’s seeds provide vital nourishment for a variety of small animals and birds, making it a perfect choice for any sustainable planting. Hoary Vervain’s leaves are also a common larval host for the Common Buckeye Butterfly. This variety grows in full sun to part shade and is extremely easy to grow.