Gardening Articles: Flowers :: Perennials
Grasses in Containers (page 2 of 4)
by Rick Darke
Using Container Grasses
The dwarfing effect of containers on grass plants makes pots the ideal way to enjoy grasses that would be too big for some garden spaces if grown in the ground.
Though many grasses look best when grown individually in pots, you can create exciting combinations by planting grasses with other flowering or foliage plants in the same pot. Because many grasses have a fairly upright, fountainlike form, plant a tumbling, spreading, or cascading plant, such as moss verbena (Verbena tenuisecta), bronze-leafed sweet potato vine (Ipomoea batatas 'Blackie'), or one of the spreading silver-leafed sages such as Artemesia schmidtiana at the base of the container to create an elegant scene.
Large grasses are useful for organizing garden spaces, creating outdoor "rooms," or serving as focal points in the same way that specimen shrubs or hedges typically do. Miscanthus, for example, is particularly well suited to cultivation in containers ranging from clay pots to half whiskey barrels to antiques such as copper boilers and tin milk cans. A tubbed specimen of miscanthus may be only half the size of an in-ground plant, yet it can serve a similar purpose. The Delaware Center for Horticulture uses a matched pair of containers planted with 'Morning Light' miscanthus to flank the front courtyard entrance doors. The fine texture of the grasses softens the bold surfaces of the building. Container-grown miscanthus can be used in similar ways to organize space in rooftop gardens and on suburban patios.
Containers are also an excellent way to enjoy spreading grasses that might otherwise be weedy nuisances in a flower border. While visiting legendary garden designer Penelope Hobhouse's garden three years ago, I was stunned by her dramatic use of blue grass (Leymus arenarius) in a large copper urn. This notorious spreader was perfectly controlled in the urn -- its colorful, straplike foliage beautifully complemented the natural patina of the copper urn and the surrounding perennials. The ribbon grasses (Phalaris arundinacea 'Picta', 'Feesey', and 'Tricolor') are all strong runners and superb candidates for containers.
Giant reed (Arundo donax) can grow nearly 14 feet tall if planted in the ground, and its stout rhizomes can cover a few feet in a single summer. In a container the size of a half whiskey barrel, however, it can be maintained at a very manageable 5 foot height. The white-striped 'Variegata' makes a particularly beautiful, modest-sized plant when grown in a container.
Growing grasses in containers sometimes reduces flowering, but in many cases that may be desirable. Blue lyme grass is less likely to bloom when confined in a pot, but the colorful foliage is this grass's main feature anyway; the flower stalks are relatively coarse and unattractive. Miscanthus is also less likely to flower when confined by a container. Although the plumy flowers are beautiful, the form, color, and texture of miscanthus foliage is quite striking by itself.
Another advantage of container gardening is the ability to shuffle plants, making new combinations over the course of a season, as plants go on and off peak. A strategically placed clump of blue oat grass (Helichtrichon sempervivens) can add a cool touch to the mid-summer garden. Since the textural beauty of grasses often remains constant throughout the year, they are especially useful for providing a reliable backdrop to various flowers and broad-leafed plants. In addition, the autumn flowering and foliage colors of many grasses can be the highlight of the late-season garden. I particularly value ornamental grasses for the way the way they are illuminated by the sun's rays, especially in fall, yet it takes careful design when laying out garden beds to ensure that grasses will be naturally backlit or sidelit. Container grasses can easily be repositioned to make the most of autumn sunstreams.