Gardens must be at once inspiring and conserving,
high-spirited and low maintenance. They must reflect and
sustain the rhythms of our lives,
our home, and our shared
places, and they must speak to us eloquently of the sun and
seasons. Delightfully, there are grasses suited to all of these ideals.
Rick Darke (2004), "Timber Press Pocket Guide To Ornamental Grasses"
Many barely known, but wonderful grasses are overlooked and never sold widely to the public because consumers are not asking for them at
their local garden centers. Commercial landscape companies have embraced the use of grasses. Unfortunately, they’ve over-used a few
selections when there are hundreds of beautiful selections they could be using. With recent studies proving some of the most common
ornamental grasses invasive, we must now look to uncommon and native selections for alternative solutions.
Maiden hair grass (Miscanthus sinensis, USDA Hardiness Zone 5) [see image at right] and fountain grass (Pennisetum alopecuroides, Zone 6),
for example, have made it to the top of some state’s invasive plant lists. Unfortunately, these selections have been used widely, and we are now starting to see problems
with invasiveness in many areas throughout the US. Luckily, there are many alternatives, and today’s ornamental grass choices are beautiful, less invasive, and quite drought
tolerant. Consumers shouldn’t feel limited to what’s offered at their local garden center or by landscape professionals. To combat overuse of a handful of grass types,
you should start requesting other selections for home or commercial use.
Some of the more interesting, unusual selections are slowly making their way into the consumer market. Though often thought of as a common roadside weed,
selections of our native switch grass (Panicum virgatum, Zone 4) are penetrating the market with steel blue and maroon foliage, long-lasting colorful
plume flowers, and truly upright habits. One of our new favorites at the Arboretum is the selection 'Northwind' (see image at left) discovered by
Roy Diblik at Northwind Perennial Farm in Lake Geneva, Wisconsin. 'Northwind' was selected for its columnar habit, steel blue foliage, and
bicolor mauve and sea foam green plumes that last well into winter. Given average water and planted in full sun, ‘Northwind’ really does stand straight,
tall, and true all summer. It’s a lovely addition to any garden providing multi-seasonal interest and winter music as the blades gently sway back and forth from the winter winds.
At the National Arboretum, we’ve fallen in love with pink muhly grass (Muhlenbergia capillaris, Zone 7) (see image at right) whose luminous cotton
candy pink plumes stop traffic in the fall. This little grass (24 – 36” high and wide) is so striking that visitors and staff alike stopped to admire it in
our new planting bed around the Administration Building this fall. Pink muhly is not a new plant, but is truly underused — there haven’t been any significant
selections made of this species to date, but some would say its beauty doesn’t need improving! It’s perfect for smaller urban gardens or massing in commercial
landscapes as just two or three plants can make a dramatic impact in any garden setting. Pink muhly prefers to be on the dry side during the winter months,
so make sure to plant it in a well-drained site.
New selections of grasses are being made often. Our horticulturists try to include these superb selections into every new garden at the National
Arboretum, as well as incorporate them into older gardens for enhanced seasonal interest. We have trialed and are displaying many unusual species
and selections in various locations throughout the Arboretum, so visit us this winter to see these grasses in full winter glory. Check back in the
future for an article on our favorite new selections of sedges (Carex sp.).
- Below is a list of some of our staff’s favorite new and underused grasses, by location.