October 2011 Plant of the Month —
Purple (or pink) muhly grass, Muhlenbergia capillaris
Purple muhly blooms in the fall, but rather than large flowers, the grassy mound is covered by a cloud of shimmering purple fog. The cultivar ‘Pink Flamingos’ (bottom photo) is said to be a hybrid of Muhlenbergia capillaris and M. lindheimeri. It grows taller and wider than traditional purple muhly grass and has spear-shaped plumes that are spectacular to behold in late fall. Photos of specimens in the UT Gardens - Jackson by Carol Reese.
Its name is ugly. Muhly grass is pronounced just like it would be if you were calling someone stubborn. There are several species, but the one most often found in the nursery trade is Muhlenbergia capillaris. You’ll hear it called pink muhly sometimes, but often in this region it goes by purple muhly. I think it sells better to manly men under that name.
All summer it sits there, looking healthy but ordinary - a mound shaped clump resembling a glaucous wiry fescue. It’s not until fall that the clump begins to bloom. Don’t get confused about the term bloom, because grass flowers are not anything like daisies or roses or impatiens. Grass flowers are tiny things, without showy petals, but there are lots and lots of them. The effect on purple muhly is filmy and cloudlike, made more so by the light stems lifting and floating on the breeze. It looks as though the grassy mound is covered by a cloud of shimmering purple fog.
Muhly grass is native to the southeast – west as far as Texas and even north to Kansas. It likes sun and can be found on a wide range of soil, from damp, to poor and rocky. Hardiness depends on the provenance. For example, plants from a Florida population will not be as hardy as those from more northerly climes, so ask the nursery about their source.
Plants will quickly grow to a symmetrical mound about three by three feet, and have never needed dividing in the several years they have grown in the UT Gardens, both in Jackson and Knoxville. No pests or diseases have troubled it, but do be sure to plant it in spring so that it will be well established by winter, as fall planted specimens have sometimes failed.
A hybrid form called ‘Pink Flamingos’ has shown up in the nursery trade the last couple of years. It is said to be a hybrid of Muhlenbergia capillaris and M. lindheimeri. It grows another foot or so wider and tall, and has distinctly spear-shaped plumes, again, spectacular in late fall. While thought to be hardy to zone 6b, remember that spring planting is advised.
Another commendable feature is these muhly grasses are apparently unappetizing to deer.
Carol Reese is the Western Region Ornamental Horticulture
Specialist for University of Tennessee Extension. Her office is located
in the West Tennessee AgResearch and Education Center in Jackson. The
UT Gardens located in Knoxville and Jackson are part of the UT
Institute of Agriculture. Their mission is to foster appreciation,
education and stewardship of plants through garden displays,
collections, educational programs and research trials. The gardens are
open during all seasons and free to the public. See http://utgardens.tennessee.edu/ and http://westtennessee.tennessee.edu/ornamentals/ for more information.
Carol Reese, UT Extension, 731-425-4767, firstname.lastname@example.org
Patricia McDaniels, UTIA Marketing and Communications Services, 615-835-4570, email@example.com