Ornamental grasses add visual interest to your garden in many ways. Grasses can add height and strong vertical lines to a planting bed, enhance privacy or attract wildlife. In containers, grasses provide texture and color at times when other plants are not blooming. While generally low-maintenance, ornamental grasses in containers need the simple attention required by other container plants. Refresh your landscape with leafy, highly decorative, easy-care ornamental grasses.
Selecting Suitable Grasses
In choosing a grass for a container, think about height, spread, color and texture. Container-suitable grasses hardy in U..S. Department of Agriculture plant hardiness zones 7 through 10 include Japanese blood grass (Imperata cylindrica "Red Baron"), a vivid 12- to 15-inch tall red-bladed grass with an open, upright growth habit, seeking full to partial sun. Juncus effusus "Quartz Creek" is a bright green rush-grass with the same growth habit, reaching 18 to 24 inches tall. Melinus nerviglumis is a semi-tropical shorter grass hardy in USDA zones 9 and 10; the "Pink Champagne" variety combines pale green leaves with small dark pink plumes that fade to pale pink/creamy white. "Fiber Optic" (Scirpus cernuus) is another species hardy in USDA zones 8 to 10. Mounded green leaves hold small white plumes throughout the growing season for a distinctive look. For large containers, Muhly grass (Muhlenbergia capillaris) is a drought-tolerant clumping Florida native approximately 2 feet tall and wide, bearing frothy pink-purple plumes spring through fall. Local varieties will add to your store of colors, shapes and heights. Avoid grasses whose descriptions emphasize rapid growth or aggressive spread -- clumping grasses with a moderate growth rate do much better in containers.
Check the species that interests you for winter-hardiness. Ornamental grasses can be either deciduous or evergreen. Deciduous grasses do well in containers intended only for growing-season use, spring through fall, but will die back or die off in winter. Evergreen grasses maintain their vitality and appearance year-round, making them the choice for permanent planters. Nurseries and catalogs often have information about seasonal behavior; another way to check is to make a nursery visit during the coldest part of the winter to see how the grass you want is behaving. Ornamental and other grasses are also customarily divided into cool-season and warm-season varieties. Put a cool-season container grass in a location out of full hot sun. Expect it to look its best in spring and fall. A warm-season grass will welcome direct sun and often dies back in winter. Choose grasses of both varieties to maintain visual interest in your yard throughout the year.
Feeding and Watering
Provide rich, loamy soil for your container, to support the growth of delicate grass roots. Soil moisture will depend on the type of grass you choose, but a regular watering schedule is essential for all container plants because of their limited soil resources. Some people find ornamental grasses nutritionally self-sufficient. Others suggest an annual feeding of a slow-release nitrogen fertilizer or general-purpose garden fertilizer, noting that high-nitrogen fertilizers promote overly rapid growth, resulting in weak, rangy stems. Annual feeding should be timed to coincide with a period of the plant's rapid growth, spring being the most common recommendation.
Most grasses need only occasional combing or other removal of dead blades, stems and debris. Cut them back in winter only if their appearance is unattractive. As with all potted perennials, watch for signs that roots have become pot-bound. Age and poor growth are your best clues; center die-out is one indication that you need to divide and repot a grass clump. Remove grass and soil from the pot, cut or pull the clump apart and replant in fresh soil. Transplanting is best done in early spring before you see signs of new growth.
- University of Illinois Extension: Maintenance of Ornamental Grasses
- University of Florida IFAS Extension: Considerations for Selection and Use of Ornamental Grasses
- University of Missouri Extension Bulletin G6661
- Master Gardeners Journal, University of Florida IFAS Extension: Ornamental Grasses
- Frederick County Master Gardeners, University of Maryland: Ornamental Grasses in Container Gardens
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