HARDINESS: Zones 3 to 10
PREFERRED SOIL pH: Near neutral
PREFERRED SOIL TYPE: Average
PREFERRED LIGHT: Sun to partial shade
ATTRIBUTES: Dramatic foliage and flower plumes; for beds, specimen plants, or pots
SEASON OF INTEREST: Year-round
FAVORITES: Maiden grasses, fountain grasses in sun; golden hakone grass in shade
QUIRKS: Most require shearing in early spring
GOOD NEIGHBORS: Black-eyed Susan, blanket flower, garden phlox, rudbeckia, sedum, yarrow
WHERE IT GROWS BEST: Varies by type; most grow best in full sun and well-drained soil
POTENTIAL PROBLEMS: Rust, a disfiguring fungal leaf disease, can occur during humid summers
RENEWING PLANTS: Lives many years; divide as needed to control the size of clumps
CRITTER RESISTANCE: Excellent
SOURCE: Bedding plants, division
DIMENSIONS: 1-6 ft (0.3-1.8 m) tall, 1-4 ft (0.3-1.2 m) wide
Perennial Grasses in the Landscape
Essential components of contemporary landscape design, perennial grasses have become very popular, and for good reason.They are the ultimate care-free plants, enriching the landscape year-round and usually requiring only to be cut back each spring to allow for lush new growth. There are numerous species of ornamental grasses, with a variety of sizes, colors, and textures appropriate for many garden situations. These plants are as comfortable in a garden that is devoted to grasses as they are standing alone as specimens or rubbing shoulders with shrubs or other perennials.
When choosing companions for grasses, select plants of similar stature and compatible needs. Tall, summer-flowering perennials, such as Joe Pye weed and black-eyed Susan, make good partners for grasses that grow to 4 ft (1.2 m) or more in height. Midsized grasses can be paired with garden phlox, daylilies, stonecrop, or purple coneflower, while smaller grasses can be grown with flowering annuals, blanket flower, and yarrow. There are also shade-tolerant grasses that look great flanked by hostas, astilbes, hellebores, and asarum.
Tall and Midsized Grasses for Sun
Maiden grass (Miscanthus sinensis) is the most widely grown ornamental grass. With graceful leaves and showy flowers that often feature curling tendrils, it is the definition of elegance. It is well adapted in Zones 5 to 9, and a few varieties, such as Purpurascens', are hardy to Zone 4. All flourish in average garden soil and grow to about 6 feet (1.8 m) tall. Foliage and flower colors vary. The green leaves of 'Purpurascens' turn rosy red with the onset of fall. 'Silver Feather' has green leaves topped by shimmering, nearly white, fan-shaped flower plumes.
Feather reed grass (Calamagrostis x acutiflora 'Karl Foerster') produces soldier-straight flowers above clean green foliage in late spring Best grown in moist, heavy soils, this grass makes a fine 5-6 ft (1.5-1.8 m) background screen for annuals and perennials in Zones 5 to 9.
Another tall and upright grass is switch grass (Paniaim virgatum), a North American native.The cultivar 'Heavy Metal' is popular for its striking blue leaf coloration, while the blades of 'Haense Herms' have a reddish cast. Easily grown in Zones 5 to 9, switch grass tolerates lean soil and salt spray and reaches a height of 4 ft (1.2 m).
Of the midsized grasses, fountain grass (Pennisetum aiopecuroide) is especially popular. It forms a neat mound, 3 ft (1 m) tall and wide, and produces dense, tawny, bottlebrush-shaped flowers. Fountain gnss takes on an attractive blond color for fall and winter. Some selections, such as the compact 'Hameln', are hardy from Zones 4 to 8. But the purple-leaved Rubrum' is often treated as an annual or grown in pots and wintered indoors because it is hardy only in Zones 9 and 10. little Blues and Japanese Red
More diminutive and prized for its unusual colored foliage, blue oat grass (Hdictotrichon sempervirens) forms a 1-2 ft (0.3-0.6 m) tall tuft of spiky, metallic blue leaves. This drought-tolerant grass is a favorite for low-maintenance plantings. Blue fescue (Festuca gfauca) looks like a miniature blue oat grass and flourishes under the same conditions. The most common cultivar is 'Elijah Blue', which stands a mere 6-8 in (15.2-20.3 cm) tall and is a good choice for edgings or rock gardens, particularly in cold climates. Blue oat grass is hardy to Zone S, but blue fescue will survive in Zone 3.
Japanese blood grass (Imperata cylindricu 'Red Baron') gets its name from the brilliant red that tips the young chartreuse leaves and then expands to flush the whole stem ruby by fall. Never more than 12 in (30.S cm) tall, Japanese blood grass produces no flowers and spreads moderately, which can be controlled by division. It grows best in Zones 5 to 8.
There is also a plentiful variety of grasses and grasslike plants that grow in shade. The sedges (Carex spp.) are the most shade tolerant, needing only indirect light. C. siderosticha 'Variegata' produces thick, arching mounds of white-rimmed, lance-shaped leaves. Its 12 in (30.5 cm) height and slowly spreading habit make it a natural choice for edging or groundcover use.
Sedge selections are numerous, are generally hardy to Zone 4 or 5, and include many shades of green.
Golden hakone grass (Hakonechioa macro 'Aureola') has golden bamboo-like leaves that form a lax, 12 in (30.5 cm) tall mop-head shape. It is particular about growing conditions, disliking dry or poorly drained soil. This grass looks best when it receives a couple of hours of morning sun and enough room for its leaves to drape naturally. It is hardy to Zone 5, but gardeners in colder climates can grow it in pots and keep it through winter in an unhealed garage.
Northern sea oats (Chasmanthium iatifolium) is a North American native that makes a soft screen or backdrop for flowers. Growing to 5 ft (1.5 m), it has slender stalks with fresh green bladelike leaves and flattened flower heads that dangle gracefully from the stems. Hardy to Zone 5, it turns yellowish tan in autumn.
Growing Perennial Grasses
Because grasses are among the most numerous and widespread plants on earth, they have a wide range of needs. However, the majority of ornamental perennial grasses require 6 hours or more of sun per day and fertile, moist, but well-drained soil.
Early spring is the best time to plant new grasses. Get them situated early in the season so that they can develop reliable roots before their vigorous growth begins in summer. Most grasses appreciate a loose, crumbly soil, so amend the site with organic matter before planting and then mulch. Fertilization is rarely necessary. When established, most grasses are quite drought tolerant.
Both the leaves and flowers dry in winter to soft shades of russet, tan, or tawny blond. To enjoy the plants'
winter glory, let the foliage remain in place until early in spring. Shear off the tattered tops before new green growth appears, leaving only 4-8 in (10.2-20.3 cm) stubs visible.This is easily done with hedge clippers or a gas- or electric-powered weed trimmer. If you accidentally wait too long, no problem; cut the grass back to a point just above the top of the new growth, and the old foliage will be shed or overgrown quickly.
Rarely visited by insect pests, grasses are usually trouble free. However, they can occasionally be plagued with rust, a fungal disease that causes raised reddish spots to appear on the leaves in damp weather. To discourage fungal infections, allow room for air to circulate between plants when you set them out, and treat rust with a commercial sulfur fungicide according to package directions.
Most ornamental grasses will live for many years, with the clumps gradually increasing in size. To contain their size, or to propagate, simply dig the clumps up in the spring and divide them into smaller, manageable clumps and replant them where you want them, setting them at the same depth as the parent plant.