Most varieties of ornamental grasses grow well in full sun and average garden soil. Keep their foliage for winter effect, cutting back all except the evergreen varieties (Festuca) before new growth emerges in the spring. Refresh Festucas by “raking” out the dried and dead leaves with gloved fingers.
Two varieties thrive in part or even full shade, expanding the possibilities for Grasses in the garden. Hakonechloa is suitable in part shade and Carex (Sedge) can thrive in full sun to full shade locations depending on the variety. Both need soil that stays evenly moist.
Transplant and divide in spring. Grasses that spread by rhizomes (“run” ) can be invasive and should be divided every year or so. Grasses that grow in clumps die out in the center and need dividing every few years.
Fertilize ornamental grasses in spring with a balanced fertilizer. We don't recommend, however, fertilizing them their first spring to allow the roots enough time to settle in before having to support their very lush top growth.
Ornamental Grasses appear to be quite deer-resistant. Evidently the sharp-edged leaves are unpalatable.
Grasses are at home in mixed borders of perennials, bulbs, and shrubs. Consider summer and fall-blooming perennials as companions: Achillea, Rudbeckia, Helenium, Asters, Monarda, Perovskia, Phlox, and Oriental Lilies. The large Miscanthus varieties work well in the back of a border, or even as single specimens. Because most grasses are sited in the middle or back of a border and are cut back in early spring, we like to plant spring-flowering bulbs around them for color early in the year. Daffodils, Tulips, and Alliums bloom while the Grasses provide little to look at. Then the Grasses and foreground perennials sprout and camouflage the bulbs' maturing foliage.