February 2007 © Janet Davis
Chosen well, ornamental grasses can
be delightful plants in all four seasons.
In early spring, the fresh green blades shoot vigorously upwards before
arching gracefully as plants mature. In
summer, whether small species like blue fescue (Festuca glauca) or big, lush ones like maiden grass (Miscanthus sinensis), their
architectural shapes and myriad hues add texture, color and a sense of
structure to the border. As a bonus, the
wind riffling and swishing through their leaves adds its own unique soundtrack
to their constant movement. From mid-summer into early autumn, ornamental
grasses begin to flower, and whether those inflorescences are feathery and
ephemeral or plume-like and tropical in appearance, they are magical and unlike
any other flowers in the garden.
But of all the seasons, winter is when the best ornamental grasses earn their aesthetic stripes. Notice I said “best”, for it’s not a given that every ornamental grass is able to withstand winter’s repeated onslaughts of snow, rain, sleet and wind; some collapse into sorry heaps with the first blizzard. But those that do winter well turn beautiful shades of beige, brown or golden bronze and look gorgeous paired with snow-dusted evergreens, trees with handsome bark such as river birch (Betula nigra) and perennials with interesting winter seedheads like purple coneflower (Echinacea purpurea).
At
Shown below are five grasses whose leaves retain enough structural integrity through March to act as accents in the winter garden. Though a few might sink a little under the weight of repeated snowfalls, they still add an attractive note.
All should be cut back in late March or early April to allow new growth to emerge which, since they are “warm-season grasses”, will not happen until the soil has reached optimal temperatures.
To add spring interest to the areas around ornamental grasses, interplant them with bulbs like chionodoxa or muscari.
Chasmanthium latifolium - Northern Sea Oats
This underused native North
American grass (shown left in September and right in January) has charming,
pendant flower panicles that likely inspired another common name, spangle
grass. Clump-forming, it’s happy in a
sunny border or lightly-shaded woodland as long as the soil is rich and moist.
It grows 3-4 feet (90-120 cm) tall in a neat, upright shape. A good companion to purple coneflower and
‘Goldsturm’ blackeyed susan. The
fluttering seedheads have an interesting, almost oat-like appearance and stay
on the plant throughout winter (and are reported to self-seed).
Miscanthus sinensis cultivars –
Maiden Grass, Chinese Silver Grass
The numerous cultivars of Miscanthus sinensis are excellent winter
landscape candidates. ‘Gracillimus’,
shown left in flower in October and right in January, has finer leaves than
most and is the picture of elegance in a garden. Later to flower than some, it needs a warm
autumn to show its blooms. ‘Malepartus’
is one of the most satisfying and readily obtainable cultivars.Its feathery,
purplish-pink flowers tend to emerge quite early in the season, making it a
good choice for colder regions where other maiden grass cultivars often do not
reach the flowering stage before frost.
The plant grows at least 5-6 feet (150-180 cm) in height with broad leaf
blades and the flower stems (shown with ice crystals in the title graphic at
the top of the page and in the first photo) add another few feet. In fall, the
foliage turns a beautiful reddish-brown and the flowers mature to
silvery-white; it stands strong throughout winter.
Panicum virgatum – Switch
Grass
All cultivars of the prairie native
switch grass (panic grass) found in the trade (e.g. ‘Heavy Metal’, ‘Warrior’,
‘Rehbraun’, ‘Prairie Sky’) are
satisfying to grow and last well through winter. Switch grass has a strong, fountain-shaped
mound of foliage and airy flowers in late summer and fall. It tolerates sandy soil and severe
drought. The fragile seedheads have
their own winter charm, especially when each graceful seed is encased in
ice. It is beautiful with any of the
blazing stars (Liatris spp.), tall
golden yarrows (Achillea) and Russian
sage (Perovskia atriplicifolia) – all
of which can also be left standing for their interesting winter seedheads.
Pennisetum alopecuroides ‘
Although feather reed grass (shown
left in July and right in January) tends to pancake a little under heavy snow, its
lovely pale beige color and narrow foliage – a little like angel hair pasta --
adds a grace note to the winter garden.
Grows about 2 feet (60 cm) tall and prefers fairly moist, rich soil. The flower spikes are like long, silvery
foxtails; they turn brown in fall and do not persist in winter. Consider fountain grass as a path edging for
its fine-textured, swirling leaves.
Grow it with purple coneflower, blackeyed susans and other prairie
natives.
Calamagrostis x acutiflora ‘Karl Foerster’ – Feather Reed Grass
‘Karl Foerster’ feather reed grass
is deservedly popular. In fact, it was named the
2001 Perennial Plant of the Year by the members of the
Perennial Plant Association. With its straight green leaves topped by feathery,
straw-colored flowers, it adds an excellent vertical accent to the garden and
is especially lovely planted en masse with
prairie natives like ‘Goldsturm’ blackeyed susan (Rudbeckia fulgida). At the
Another fine grass with winter presence is diminutive golden Hakone grass (Hakonechloa macra ‘Aureola’). Although it doesn’t achieve the heights of the grasses above, its stunning golden summer leaves turn a rich cinnamon-brown in winter.