Whipple's Penstemon (Penstemon whippleanus) is a beautiful penstemon variety that works well in areas where more moisture and fertile soils are required. The foliage is bright green, thinner, and glossier than other penstemon varieties. Attractive flowers appear at the top of the stems in late spring to early summer. These flowers are usually a dark purple, but can also be white, light grey, blue, or wine colored as well. Unlike other penstemons, Whipple's prefers some partial shade and more water. It is less drought tolerant than other varieties and will require regular irrigation. Use as an attractive vertical accent in garden beds and borders, cottage gardens, or the edge of a shade garden.