With foliage as close to blue as anything you'll get, Blue Dune Lyme Grass (Leymus Blue Dune) couldn't be more aptly named. Combine it in beds of purple or yellow flowers, plant it in the driest of gardens, or use it for erosion control. It's quite a vigorous grower, so give it plenty of space. You can keep it contained in more formal garden spaces by planting it in pots submerged in the soil. The foliage looks great in flower arrangements!