Sonoma County Master Gardeners Helping Sonoma Gardeners

by Sonoma County Master Gardener Steven Hightower

To review some important statistics from a lawn alternatives article we ran last year--A Lawn or Not: typical turfgrass uses 5,600 gallons of water per month per 1000 square feet of lawn (that’s only 20 ft by 50 ft). That’s 20-plus thousand gallons, in the summer alone. According to the Sonoma County Water Agency, the average three-person family in a single-family home uses approximately 60-80,000 gallons per year for lawn. Given water restrictions imposed last year, and the increasing evidence of climate change, reduced water supplies and rising drought conditions, it makes less and less sense to support significant amounts of water-sucking lawn.

Our first lawn alternatives article suggested numerous options to lawn, including Mediterranean planting, Xeriscape, herbaceous borders, and natural or native plantings. But what if you still want ‘grassy’ What if you want what’s closest to lawn in look, but with a much more water-efficient profile? Or a combination of lawn-like areas and larger grasses? Then think water-wise bunch and mound grasses—sometimes known as ornamental grasses.

There are several families of grass-like plants: Poaceae, true grasses, Cyperaceae, the sedges, Restionaceae, the restios, Juncaceae, the rushes, and Typhaceae, the cattails. Bamboo are also actually grasses, being in the Bambusoideae sub-family of Poaceae, and several Nolinas are quite grass-like. Much confusion can exist in the naming of grasses, as things may have the words ‘grass’ or ‘rush’ or ‘sedge’ in their common name, and actually be in another family. But what really matters is the look you are trying to achieve, and the suitability of the particular grass plant for your location, exposure and climate. You needn’t be concerned with nomenclature, as most of these plants coexist quite happily.

Some grasses, such as many Miscanthus and Pennisetum sport beautiful, feathery plumes that wave in the breeze. Others like Muhlenbergia capillaris (Muhly grass) may show lovely purple or bronze colors, and some, such as Pennisetum setaceum Rubrum (purple fountain grass) combine both. There are several varieties that are interesting shades of blue, including Helictotrichon sempervirens (blue oatgrass), Schizachyrium scoparium (little bluestem), Leymus arenarius Blue Dune and the festuca glaucas (blue fescues). And there are many variegated grasses, such as Miscanthus sinensis ‘Morning Light’ or Carex oshimensis (variegated Japanese sedge) to add interest. Certain grass varieties will stay green year-round, and some will turn tan, brown, golden or reddish when dormant. Some, such as many natives, require no supplemental water once established, and others may require occasional watering, but will use nowhere near the amounts of water as turf.

While certain varieties will grow large, and stay very individually mounded, other varieties will merge together in an undulating swath, such as Carex pansa (California meadow sedge), Carex tumilicola (Berkeley sedge) and Carex subfusca (Monterey Sedge). You can mix and match both low and large. Ornamental grass replacements for lawns require less maintenance, as well as less water. Care varies by species, but might include trimming 2-3 times a season, or annual pruning, no edging, minimal fertilization and easier weeding, if mulched while it grows in. Watering ranges from no supplemental once established, to once or twice a week, at most, rather than virtually daily as for lawn.

A design challenge came recently when a friend with several areas of lawn had a mid-summer water bill (under current restrictions and tiered pricing) in excess of $1000! First up was a 15‘ deep x 40’ wide area of lawn, roughly rectangular in shape, that borders a driveway on one side, and an area of shrubs on the other, which is backed by some property-line screening trees. As replacement we looked at planting a 5’ wide strip of mixed larger grasses, including Pennisetum alopecuroides ‘Viridescens’ Black fountain grass), Nassella tenuissima (Mexican feather grass), and Nolina texana (Beargrass) towards the rear, and for the front two-thirds carex tumulicola (Berkeley sedge) - which creates a lush, meadow-like effect. The result will be an undulating rough lawn-like look in the bulk of the parcel, and a transition of taller mounding grasses between that and the tree-line.

At the rear of the house was a section of lawn in full sun behind a pool, backed by an arbor of wisteria and hedged on the sides by rosemary. Here we looked at a stone path from pool to arbor planted with a border of Miscanthus sinensis Arabesque (Japanese silver grass), Panicum virgatum (Blue switch grass) and Muhlenbergia capillaris (Muhly grass), with accents of spiky Yucca Whipplei and a bright Phormium (New Zealand flax)--all sun lovers and drought tolerant. The main areas combine a mixture of Festuca glaucas—silvery-blue Elijah’s Blue, Festuca amethystina Superba and green-blue Meerblau with camel-tinged seed heads. As these grow in, they will form a rumpled-blue carpet of merged mound grasses beside borders combining salmon-white plumes carried on handsome burgundy stems, stunning reddish purple flower plumes and delicate pink seed panicles punctuated by architectural blue and bronze-orange spikes.

In another situation one might create a “prairie” landscape to replace a water-sucking expanse of lawn that once was used by the children for play, but which hasn’t been needed that way for years. You can mix grasses of different shapes and heights, that take little water and don’t need mowing more than once or twice a year: Panicum virgatum (switchgrass), Schizachyrium scoparium (little bluestem), Sporobolus heterolepsis (prairie dropseed) and Helictotrichon sempervirens (blue oatgrass). A variety of perennials mix well, too, in a prairie type setting. Blend in Coreopsis, (tickseed), Echinacea (coneflower), Perovskia (Russian sage), Eschscholzia (poppies) or Gaura for color and contrast.

In a more urban setting it might be desirable to replace one of the dreaded boring grass strips between sidewalk and curb. Again, Carex pansa or Carex praegracilis would provide a lawn-like undulating swath, or a blue fescue would create that nubby blue-green carpet.

California natives can be a good choice, and can provide a quite natural look—again a sort of prairie-like look—to set against or transition to native landscape of oaks, madrones, bay, manzanita, toyon and the like. Combine them in a border strip between more formal garden plantings and the natural countryside. Interesting choices here could include Carex praegracilis (Clustered field sedge) Muhlenbergia rigens (Deergrass), Festuca californica (California fescue), Nassella pulchra (Purple needlegrass), Deschampsia cespitosa (Tufted hair grass), and Carex tumulicola (Berkeley sedge). Natural-looking transitioning between cultivated areas and the Sonoma County countryside calls for having the transition plantings mimic the natural surroundings by keeping them rougher and less pruned, and using masses of plants as well as intermixed planting.

The popularity of ornamental grasses has grown widely in the last dozen years, due to both their good looks, ease of maintenance, and water-wise nature. If you can identify an area of lawn that you don't really need any more, take the plunge and create an interesting palate of mounding grasses. Local nurseries including Emerisa Gardens and Cal Flora (natives) in Santa Rosa, Cottage Gardens in Petaluma and Sonoma Mission Gardens in Sonoma carry a good variety of grasses. Digging Dog nursery in Mendocino carries a large selection, as well, and has a lovely display garden for those of you willing to make the trip to Albion. If not, they have a website for mail-order and their handiwork can be viewed at Matanzas Creek Winery in Santa Rosa – one of the best displays of ornamental grasses and companion plantings in the County.

©Sonoma County Master Gardeners