'Dallas Blues' Switch Grass (Panicum virgatum 'Dallas Blues') is a fast-growing perennial grass that can reach 4 feet tall and just as wide. It has graceful green or gray-green leaves and an upright habit and in midsummer bears slender purple or red flowers. It likes sun or shade, is highly drought tolerant, and attracts wildlife. Note: Its elegant, upright form makes it highly effective as an entryway planting.