The Dry Garden: Ornamental grasses, poetry in motion
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There is nothing lovelier than tall ornamental grasses, backlit and waving in a breeze. Even vacant lots can produce stands of car-crash-inducing beauty. So when gardeners hope to capture some of that lyrical action for their own homes, it’s logical to assume that all one need do is stop mowing the lawn. Alas, that would be wrong. Harnessing the tousled romance of ornamental grasses (and plants that look like these grasses) is so hard that even experienced horticulturists factor generous time and space for trial and error into their approaches before they have, in effect, allowed the right plant to do its stuff in the right place.
Among the challenges are discovering these meadow grasses’ growing seasons, understanding which ones are invasive, watering them enough but not too much, deducing where they are happiest, out-competing unwanted turf grasses and remnants of lawn and, hardest of all, mastering scale. If you haven’t put a tall grass where a short one would be better, or big one where a small one should have gone, you haven’t been bitten by the meadow bug.
Grasses and their doppelganger cousins -- rushes and sedges -- come in so many shapes, sizes and habits that they can serve as filler, accent or focal point in a garden. These ultimate functions are rarely clear when they are enigmatic little clumps sitting in flats or 1 gallon pots on nursery shelves. Repeating the mnemonic “sedges have edges, rushes are round, grasses are hollow right up from the ground” will help take the edge off as you admit helplessness and look for a knowledgeable store clerk.
Given that knowledgeable staff in garden centers are almost as rare as hens teeth, the best place to go for help is the Theodore Payne Foundation for Wildflowers and Native Plants in Sun Valley, above right. Signage around an impressive and growing selection of grasses alerts shoppers to what might be Lesson No. 1 in landscaping with grasses: These plants divide into two distinct classes of cool and warm season growers. So if you want growth and color in fall, winter and early spring, go for cool season. If you want it in summer, choose warm season. Payne also has helpfully divided the grasses and sedges into separate areas for plants favoring wetter or drier conditions.
An equally pressing consideration is size. If you are shopping for low-growing but more blowsy and natural looking substitutes for lawn, or transition plants from lawn to meadow, a safe place to start is with the fescue grasses, including Festuca rubra, or the small sedges such as Carex pansa or Carex praegracilis, pictured at the top of this post. The area near the Payne Foundation shop is planted with red fescue for those who want to see it in action, and the nursery stocks at least five other species and more than twice the number of carexes. At her home in South Pasadena, horticulturist Barbara Eisenstein has been slowly peeling back turf and replacing it with meadow and woodland complexes of plants including native grasses. She starts small, sees how it works, then, in true gardener fashion, expands on the successes and removes the failures. A charming success is the dotting of fescue clumps that soften a border between receding lawn and wildflowers.
For those looking for a lawn substitute, Eisenstein’s friend and fellow horticulturist Bart O’Brien praises the sedge Carex praegracilis for density of cover, drought tolerance and the rhizomatic ability to keep on running until a sidewalk or wall stops it. “Carex praegracilis is very forgiving about watering,” he said. “If you don’t water it, sure it will go brown, but if you start watering it will green up.’
In Eisenstein’s rear garden, faced with a displeasingly sharp transition between lawn and a mulched area under a tree, Eisenstein followed O’Brien’s suggestion of using a bunching deergrass called Muhlenbergia rigens as a bridge. Placed artfully by Eisenstein, a succession of clumped deer grass even defines an informal path, below.
To see the potential for deer grass when massed, a trip is in order to Rancho Santa Ana Botanic Garden in Claremont, where a 12-year old meadow planted by O’Brien may be the best planting of its sort in Southern California. The components of the dry meadow around Rancho’s teaching center could not be simpler: an informal hedge of low-growing coyote bush (a type of Baccharis pitularis named Pigeon Point), then a mix of Muhlenbergia rigens, white sage, native fuchsia and some seasonal milkweeds.
Using ornamental grasses effectively is a huge subject. Yet even this peek must come with a warning. One need only look at the hillsides around Los Angeles to see past ravages of our running passion for the radiant and supple beauty that grass can bring to a landscape. The streams are clogged with the once fashionable reed Arundo donax. Our local mountains and highway verges are infested with pampas grass. Fountain grass and the dangerously popular and still widely sold Mexican feather grass are jumping from yards into wild lands.
Invasive plants have dire effects on watersheds, fire ecology and animal life. Before planting any ornamental grass, check the California Invasive Plant Council guide.
It is not just wild lands at risk. The most beloved native plants can be bad actors in home gardens. Nassella pulchra, or purple needlegrass, right, or any grass with “needle” in the common name, should probably not be planted in a home garden if you have pets or small children. Their dried seeds, or awns, can get in a pet’s paws, eyes and nose and, when dried, even puncture human skin. The dreaded foxtail isn’t necessarily one species of grass; it’s anything with sharp awns capable of piercing skin.
-- Emily Green
The Dry Garden, Green’s column on low-water landscaping, appears here on Fridays. For an easy way to follow future installments, join our Facebook page for gardening in the West.
The deer grass meadow at Rancho Santa Ana Botanic Garden in Claremont.
Photo, top: Irfan Khan / Los Angeles Times
All other photos: Emily Green