In these columns, we initiated an exploration of ornamental grass, and looked specifically at Grey Sedge (Carex divulsa), a member of the sedge family.
Next month, after dividing and moving several specimens of this plant in my garden, I will replace them with grasses that are more appropriate for a bed of California native plants. That activity should be done in the early fall, as the plants enter dormancy.
Meanwhile, the project involves learning about California native grasses. Today’s column presents brief descriptions of examples of true grasses that would grow well in the Monterey Bay area. We focus here on ornamental grasses, not turf grasses. The smaller ornamental grasses can be used to create a natural meadow as an alternative to the typical lawn that gardeners use to emulate a carpet.
Nearly all grasses, despite their origins, would grow well in this area’s moderate climate. An informal survey of ornamental grasses has identified a few that grow best with a winter chill, but with those exceptions, local gardeners could select any of the many available ornamental grasses for their landscape. An emphasis on California native grasses reflects adherence to a thematic approach to the landscape and recognition of the native fauna’s compatibility with native plants.
Grasses may be described in terms of size, preference for sun or shade, and whether they grow in fall or summer.
In this area, cool-season grasses are generally favored in coastal California. These are grasses that begin annual growth with the onset of fall rains, flower in the spring or summer, and then enter dormancy.
In comparison, warm-season grasses grow in early summer, flower in mid- to late- summer, and are dormant throughout the winter.
For both types, the growing season continues for about half of the year, and the dormant period extends through the other half. Dormancy means that the grasses turn golden (or brown if you prefer), and could be either sheared or left natural.
Grasses present their best appearance when divided after three or four years of growth.
Nora Harlow and Kristin Jakob, editors of Wild Lilies, Irises, and Grasses: Gardening with California Monocots (University of California Press, 2003) provided a useful overview of California native grasses. Here are selected examples in various size categories.
Blue Grama/Eyelash Grass (Bouteloua gracilis) grows 1.5-2 ft. high, 1 ft. wide. This is a versatile and fascinating small grass that flowers in odd inflorescences that spring from the stems at angles that remind some observers of hovering mosquitos. This grass can be massed for a meadow effect or grown in small clusters in a border or rock garden.
Leafy Reed-grass (Calamagrostis foliosa). 1 ft. high, 1-1.5 wide. Harlow and Jakob wrote this is “arguably California’s most beautiful native grass…it makes the transition [from nature] to gardens with great styles and beauty.” A cool-season grower, this grass grows in full sun or light shade, tolerates seashore wind and salt spray, and resists attacks by herbivores. Looks best when combed during the dormant season, rather than sheared.
Nodding Needlegrass (Nassella cernua) 1 ft. high with flowering spikes up to 3 ft. high; 2 ft. wide. This is a cool-season clump former, with gray-green leaves and long purple-toned awns (bristles) that create a feathery look to the inflorescence. It has been called “…perhaps the most elegant of California’s native needle grasses. ” Needs full sun or part sun.
California Fescue (Festuca californica) 2-3 ft. high, 1-2 ft. wide. A handsome bunchgrass with foliage that ranges from green to blue-green to gray-blue. The flower stalks emerge from the center of the clump and “arch elegantly outward.”
Deer Grass (Muhlenbergia rigens) 4-5 ft. high, 6 ft. wide. “Long silver-gray flower panicles arch gracefully three feet over the gray-green foliage.” This grass will grow well without irrigation (once established) but with regular irrigation will be nearly evergreen. Works in mass plantings or as a dramatic specimen.
Grasses can bring an attractive appearance in the garden, interesting movement with breezes, and contrast with the form of typical garden dicots. The gardener should visualize the mature size of an ornamental grass selection in order to place it most effectively as a groundcover, filler or accent.