By Debbie Hager
UCCE / El Dorado County Master Gardener
The beauty of ornamental grasses is very apparent in the fall when the inflorescences (seed heads) are large and their foliage glows in the autumn light. Grasses offer a sense of movement in the garden and display seasonal changes. Ornamental grasses add texture, form and sound to the garden. They look good all season long with minimal care.
Grasses are easy to grow in most types of soil. Most grasses require only average water once established and some are very drought tolerant and enjoy full sun. Another plus to ornamental grasses is that deer rarely bother them.
Grasses require at most, one annual pruning. Some types can get by with only occasional trimming, every few years. It’s a matter of choice whether you cut back your ornamental grasses in late fall or early spring. The perennial grasses that die back in winter can be rejuvenated by cutting the foliage of the grass back to within three to four inches above the crown of the plant. Don’t wait too long or you risk cutting off the tips of the new season’s growth. Many evergreen grasses and sedges do not need to be cut back yearly and many grow attractively for a number of years with minor grooming.
Grasses grow from a root crown that sits at or below the soil level. Over time the new growth may only appear at the outside edges of the plant and the center dies out. This condition indicates that too much woody, old growth has smothered the room for new growth.
Such plants can usually be renewed by division and transplanting. For small and medium sized grasses, it is best to lift clumps from the ground with a sharp trowel or spade and use a knife to divide the clumps. Discard dead material from the center and replant healthy live divisions from outside of the center clump. Divisions should be thoroughly watered immediately following planting.
A sharp, sturdy spade is necessary for dividing larger grasses. Mature grasses are often too big and heavy to be lifted in one piece. First, section the ground around the grass with a spade by cutting a circle around the clump, then, lift it out. Replant the division in same manner as the small and medium sized grasses. Gloves are important to protect your hands against cuts because some grasses have sharp leaf margins. Dividing grasses can be done in the late fall or early spring. Replant as soon as possible after dividing; don’t let the grass roots dry out. Keep the grass divisions well watered until you see signs of new growth.
Grasses are excellent container plants. Ornamental grasses planted as bold specimen plants should have enough open space around them to show off their arching or vertical habit and their bloom inflorescences. Most grasses prefer full sun, but Japanese forest grass (Hakonechloa) prefers shade and has a beautiful tumbling wave form. Foerster’s feather reed grass (Calamagrostis arundinacea ‘Karl Foerster’) has a striking vertical form that looks great in narrow spaces. It has upright dark green foliage and fluffy blooms in spring that turn into attractive buff spikes that last all summer and fall. Foerster is a UC Davis Arboretum All Star plant as is deer grass (Muhlenbergia rigens). Deer grass is a California native plant. It can grow five feet high and three feet wide and makes a bold statement in any garden. Mexican feather grass (Stipa tenuissima) has fine textured, soft green foliage and is beautiful as it moves in the breeze. It happily reseeds, however, so be forewarned as it can become invasive.
Grasses look beautiful combined with summer and fall blooming perennials like ornamental sages (Salvias), coneflowers (Echinacea) and bee balm (Monarda). Planted individually as specimens, in groups or in containers, few plants offer as much in the way of year round interest and beauty as grasses do. Once established, ornamental grasses need very little in terms of supplemental water, fertilizer or maintenance.
Learn about using a different type of grass in a new way in your garden. UCCE Master Gardeners will present a free class on “Straw Bale Gardening” on Saturday, Oct. 30. The class starts at 9 a.m. and will be held in the Veterans Memorial Building at 130 Placerville Dr. in Placerville.
Master Gardeners are available to answer home gardening questions Tuesday through Friday, 9 a.m. to noon, by calling 530-621-5512. Walk-ins are welcome. The office is located at 311 Fair Lane in Placerville. For more information about our public education classes and activities, go to the Master Gardener Website at ceeldorado.ucdavis.edu/Master_Gardener/.