The term "ornamental grass" applies not only to the true grasses, but to closely related grass-like plants as well. Together, these plants compose one of the largest groups of plants on the planet. And while most everyone knows what lawn is, many gardeners are just now becoming familiar with ornamental grasses.

The basics of grass gardening are easy to understand. Some grasses creep or spread, others stay in tight, well-mannered clumps. Some grasses are evergreen and hold their foliage year-round; these are called cool-season grasses.  Festucas, Kolerias, and many Sedges are considered cool-season grasses. Cool-season grasses are usually early bloomers and are often selected for their foliage color and texture.

By contrast, warm-season grasses are dormant in winter and begin growing in the spring, flowering in summer or fall. With the shortening days and cooler temperatures of autumn, many warm-season grasses put on a fabulous display of fall color. Some of the warm-season grasses noted for their spectacular fall color are Maiden Grass (Miscanthus sinensis) and Switch Grass (Panicum virgatum).

Once you know whether a grass is evergreen or deciduous (cool-season vs. warm-season), clumping or spreading, make sure you are choosing a grass that thrives in your climate and soil. Mexican Feather Grass (Stipa tenuissima), for instance, thrives in hot deserts and heavy clay soils, which would not support other grasses. Another common mistake made by gardeners unfamiliar with grasses is to underestimate their potential size. A four-inch pot of Maiden Grass (Miscanthus sinensis ‘Gracillimus’) could grow four feet high and as wide in one season! To avoid crowding, give large varieties plenty of room, or choose compact forms for small gardens.

Use ornamental grasses the way you would use any other perennial, singularly for accent, or in groups for massing. In the shade, for flowering accent, try Northern Sea Oats (Chasmanthium latifolium), Korean Feather Reed Grass (Calamagrostis brachytricha), or any of the Hair Grass (Deschampsia). For a tall, bold-flowering accent, try Plume Grass (Erianthus ravennae) or Maiden Grass (Miscanthus sinensis ‘Gracillimus’). In a perennial border, try any of the Fountain grasses (Pennisetum) or the always dependable Feather Reed Grass (Calamagrostis acutiflora stricta). For foliage accent, try the Blue Fescue (Festuca ‘Elijah Blue’) or the copper-colored Carex comans ‘Bronze.’ With so many grasses to choose from, why not put an ornamental Grass in your garden this season?

Plant grasses in early spring as soon as you can work the soil. Mulch right after planting. Water at least once a week to establish the new plants. Fertilize rarely or never; most grasses grow well in ordinary garden soil, and feeding will only leave them over-lush and limp.
Remove old stalks and foliage in late winter or early spring to make room for new growth. Use hedge shears or loppers.

Large clumps of grasses in open areas can be left alone for decades. There is no need to divide established grasses except when they are old, overgrown, or crowded, or when you want to keep them within the bounds of your design. (grasses may also benefit from being divided and moved when a nearby shrub or tree begins to cast too much shade.) After lifting and dividing a clump—in early spring for most varieties—with a spade, ax, or saw, replant the healthiest pieces and discard the dead center. Be sure to place aggressive spreaders where you won’t need to worry about dividing them.