Trees, shrubs and flowers aren't the only landscaping options. Ornamental grasses can also add interest.
Ornamental grasses are those that have decorative characteristics. They will grow without pruning or mowing. Grasses are ever-changing -- offering a few green shoots in spring, maturing into a plant that can arch over a wall, grow tall, flower or completely dominate a sunny meadow by the end of the season. Many grasses are perennial and return stronger each year. Divide every few years if needed.
Among the assets ornamental grasses can offer are evergreen foliage, shade tolerance, showy flowers, screening, massive size, dainty habit, winter interest, graceful arching form, strict upright growth, drifts to cover a wide area and simple accents to your perennial border. Here are some grasses or sedges to consider:
* Evergreen: Pendulous sedge (Carex pendula) is a clump-forming, shade-tolerant, moisture-loving plant. The leaf blades are long and pendulous. The flowers are distinctly weeping and grow on vertical stalks that can reach six feet in height. When in flower, its form can make quite a focal point. The leaves can burn if not protected from full sun. We have it planted in woods that were taken over by deer and rabbits, and this evergreen member of the sedge family has never been eaten by these herbivores (so far). It is slow growing: Over three years, it has formed a low evergreen clump about three feet across.
* Shade tolerance: Kan suge sedge (Carex morrowii var. morrowii Kan suge) is a favorite of mine for its shade and moisture tolerance and interesting foliage. This sedge sports a white stripe down the center of the tough leaf. There are forms that have a fine weeping texture and others with a wider straplike blade that have a more visible variegation. Many of the hundreds of moisture-loving sedges are tough plants and an asset to the shade garden. This one-foot-tall by two-feet-wide evergreen sedge brightens a dark spot with its yellow or cream colored variegation.
* Showy flowers: Compact pampas grass (Cortaderia selloana "Pumila") displays an outstanding inflorescence, or cluster of flowers. Most ornamental grasses are used in design as much for the architectural effect of their foliage as for their flowers. Compact pampas is by far one of the showiest, with large, fluffy white plumes that are six to 12 inches long, three to four inches wide, appear in late summer and hold into winter. Planted in full sun, its hardiness is superior to that of most other pampas grasses.
* Screening: Giant miscanthus (M. "giganteus") will grow into a graceful screen, 10 to 12 feet tall. It has the same form and flower of the other Japanese silver grasses, except its inflorescence towers over the others. It needs to be planted in full sun, and you must be aware of its mature size in advance, because in April it's a low plant, but by August it could be growing through the canopy of a low-branching tree overhead. It is a clump-forming grass and doesn't self-sow. You will want to locate several around the property where you want summer and fall screening. The roots are tough to chop through once established.
* Massive Size: Giant reed (Arundo donax), when mature, can reach 15 feet in a season and will get impressively massive. It's the largest-growing cool-season ornamental grass and can have a dramatic effect in the landscape. This European native is an excellent plant to have at the back of a border, peeking over a fence or along the pool or water garden where it naturally occurs. Grow it in a container or in the ground. Giant reed will seldom flower and seed. It spreads by rhizomes, but they are easy to keep inbounds.
* Dainty: Hamlin Japanese fountain grass (Pennisetum alopecuroides "Hamlin") has taken the dense growing fountain grass to a manageable point, while maintaining the ornamental characteristics. The species is such a vigorous grower and self-seeds so profusely that it is too invasive to control. This diminutive hybrid is easily controlled. The flowers are showy but smaller, and it grows only two to three feet tall, with a lighter texture than the species. They are flowering now and are popularly used as a ground cover in large beds.
* Winter interest: Elliot's broom-sedge (Andropogon gyrans) takes on a vivid orange color in fall and holds its color throughout most of the winter. It will grow in wet or dry conditions and is a native plant that has interesting inflorescence and fall and winter interest. The stems are used in dry arrangements. It is a clump-forming grass that looks good in groupings with other meadow grasses or in masses among perennials that freeze back and lose interest in winter. Broom-sedge is a true grass, not a sedge.
* Graceful, arching habit: Golden hakone grass (Hakonechloa macra "Aureola") will give you some interesting design effects in fairly heavy shade with its golden variegated foliage. It can be so brilliant, yet graceful, that in a dark corner of your shady garden, on a cloudy day, it can look like the sun is shining and the wind is blowing on its 15- to 18-inch mounded cascading foliage. Hakone makes a beautiful edging plant for the border of a shade garden.
* Strict, upright habit: Karl Foerster feather reed (Calamagrostis X acutiflora "Karl Foerster") is an easily grown and managed clump-forming grass with a dependable vertical growth habit and inflorescence starting in June and lasting into fall. The strict upright form can create a wall effect when used in strong repetition. Planted on a berm or hillside, it will wave in the slightest of breezes and offer privacy in winter. When designed in groupings with shrubs or perennials, it offers a contrasting texture and form. It grows five to six feet tall, including the dense flowering stems.
* Drifts: Broom-sedge (Andropogon virginicus) is not for the small garden. It will spread over a large area, which is part of the ornamental appeal in winter. It presents a drift of grassy meadow that is most ornamental throughout the growing season and in fall, turns reddish-orange and will peek out through the snow cover in winter. It is best planted as a mono-culture (alone) or in conjunction with a grass that can compete, like Elliotts broom-sedge.
* Accent to your perennial border: Switchgrass (Panicum virgatum) is a good plant to work into the perennial border, because it holds architectural interest well into winter and fits in with other perennials, such as day lilies, black-eyed Susans, bleeding hearts, Shasta daisies, hostas and astilbes. It is difficult to choose a favorite hybrid. Switchgrasses are all so different, each one with its own unique habit, but they are all sturdy plants that make excellent focal points in the perennial garden.
Grasses thrive in organic, well-drained soil and don't need regular fertilizing. The only maintenance is annual renewal when leaves are dead. Cut them to about four to six inches. Some can be tough. If you can, use a lawn mower on its maximum height setting or try a scythe or a machete. Cut the dead stems standing in winter before they start to grow. Note: Do not mow down evergreen grass such as pendulous sedge; it will be slow to renew.
A thorough, scholarly handbook that's valuable for identification and information is the "Timber Press Pocket Guide to Ornamental Grasses" by Rick Darke (2004, $19.95).
Joel M. Lerner is president of Environmental Design in Capitol View Park, Md. E-mail or contact him through his Web site, www.gardenlerner.com.