Airy and elegant. This perennial is known for its lacy, lavender flowers with soft-yellow centers and blue-green foliage. It will bloom from mid-late summer and grows to be about 4-6 feet tall and 2-3 feet wide. You'll love the vertical lines that the purple stems add to your garden. It's also deer and rabbit tolerant and thrives in full sun or part shade in well-draining soil.