Ornamental grasses are one of those plant families that you either like a great deal or you don’t. (By ornamental, I mean the taller clumping varieties, not turf or groundcovers like carex and liriope.) One reason these grasses are under-utilized is a lack of imagination in using them effectively. The more you know how to play up their best features, the more there is to like.
I wasn’t always a grass fan. But after experimenting with several cultivars over the years I’ve come to truly appreciate their texture, drama and heft. Most are super-easy to grow and nearly disease-proof. They come in varying heights and habits too, so you’re sure to find one that works in your landscape.
Terrific as they are, grasses are not without character flaws. The bigger ones can be thuggish and hog up precious space if not sited properly. Over-wintering voles love to burrow in the crown thatch. If left standing, winter storms often collapse them into a sodden mess. By March, the clumps are breaking down regardless, and it’s a challenge to corral the loose stalks blowing all over the place.
The obvious solution is to cut them down in late fall and forego the winter show, and many people do. I like to leave mine standing for as long as possible. The bleached seedheads look gorgeous on frosty mornings, and again in the afternoon when backlit by low sun. Their feathery bulk welcomes you into the winter landscape like a giant fur coat. Either way, the only maintenance needed is an annual buzz-cut right to the ground. Not a lot to ask for eight months or more of hands-off interest. Getting rid of the canes is often more of a pain than cutting them down!
Why else would you want to plant ornamental grasses? Personally I love their curvy lines, textural contrast and wonderful movement. They catch the light like no other plant, and they are ever-changing. In fact, they contribute substantially to the mood of a garden or meadow. And if you’re interested in creating a more wild space, grasses will be indispensible in helping you do that.
The swish of rustling blades in a breeze is strangely calming, for me at least. I find that small fountains of grass can soften a driveway edge, accent a water feature or hide the HVAC unit — so versatile! Massed or grouped, grasses can provide a foil for companion plants or signal a transition from tended beds to wilder areas. They look wonderful next to boulders and walls. Finally, they thrive in hot, sunny areas with zero care from you. That’s impressive in my book.
Unfortunately not all these beautiful grasses thrive in Pennsylvania’s heavy clay, especially through our wet winters, and zone 6 is too cold for some of the best warm weather types. Those are better left to the arid Southwest or at least west of the Rockies. And the very largest specimens look best in open, expansive landscapes, not small yards.
Cultivars to Skip:
- Mexican Hair Grass – A low, wispy, fine-textured grass that is beautiful, but once established (in zone 6) is highly invasive. Paradoxically, it’s also unreliable here. I tried a dozen plugs or so and only a few survived, but four years on I’m still pulling the stragglers out. Not a good choice for this part of the country.
- Pink Muhly Grass – A gorgeous grass for some areas of zone 7 and warmer. Sadly, it’s also very unreliable in zone 6 (and parts of 7) unless you have a highly protected spot like next to a sunny wall. Nevertheless, increasingly I see it for sale here. But Muhly grass often dies out over our winters, as it dislikes wet conditions and freezing temps.
- Miscanthus Gracillimus – At 8 X 8 feet, this huge grass can grow out of scale in many suburban settings. It also reseeds readily; not a good combination. Use Morning Light or Adagio instead, which look similar but stay manageable.
- Others – Some native prairie species only thrive in xeric conditions. Whether or not they will do well for you in zone 6 (or now 7) is a gamble, and success will depend greatly on having superior drainage, good weather, and a site they like. Do your research before taking a gamble.
Fortunately there’s still plenty to choose from. A few I recommend:
Miscanthus sinensis (Maidengrass or Chinese Silvergrass)
A terrific family of grasses originating from Asia. These cultivars will thrive in most any soil except super-wet. Give them full sun for best flowering and to avoid flopping. Trouble-free. Here are three:
M. Morning Light
A large, fine-textured beauty that impresses for three seasons. At 5 x 4 feet, give it plenty of room; it will slowly expand from the base. (This year, mine topped 6 feet in bloom with a two-foot diameter base each.) As the name implies, this grass is especially lovely when backlit with dew. Thin pinstripes give its cool blades a silvery sheen. In October and November, a haze of copper inflorescenses emerge before the whole plant slowly bleaches wheat. A mature clump in full sun will hold up in all but the worst storms. Highly recommended. A down side is that clumps will continue to spread every year, and will eventually need dividing.
M. Adagio
Adagio grows a little shorter than Morning Light, about 5 feet high and wide. It features tawny-cream pennants held well above the deep green blades marked with a white midline. A lively grass with a well-defined spherical silhouette, it ages to soft beige. A good choice for part sun, as it will tolerate some shade without flopping. Excellent paired with conifers, daylilies, viburnum and similar substantial companions. A beautiful foundation grass too.
M. Variegatus
This variegated form is also slightly smaller than Morning Light. I don’t currently grow it, but I did at my previous residence as shown here. Its pistachio-and-white foliage simply glows in strong sunlight, and it will command attention wherever you put it. A lovely foil for lilies and hydrangea. Very similar habit to Morning Light with soft, copper-pink inflorescences. It is floppier in winter as it’s not quite as vigorous, but still worth growing for its fabulous summer presence.
Miscanthus purpurascens (Flame Grass)
This cultivar reminds me of scaled-down pampas grass, with prominent creamy flags fluttering high over mounded tall clumps. Use this cultivar for its sturdy stature and outstanding autumn shades of apricot and rose-gold. Conifers or euonymous make fine companions. I grew this grass at my previous property and never tired of its superb fall show that lasted for weeks. The blades can be very sharp-edged, so use caution around it and wear heavy gloves when cutting back.
Schizachyrium scoparium (Little Bluestem)
Little Bluestem starts out as a blue-green bunchgrass that creates narrow, 18″ tall vertical stands. The delicate seedheads are barely visible until they go to seed, when the entire clump appears studded with tiny stars. The main reason to grow it is for its persistent mahogany-red color from early fall into winter. When massed it can be stunning.
Even better, Little Bluestem is a North American “nativar” that stays well-behaved and doesn’t reseed readily. (Its larger cousin, Big Bluestem, is a different story and not recommended.) It can take several years for Little Bluestem to establish, so have patience. Some years the color is much prettier than others. Best for informal meadow plantings, but demure enough for casual borders too.
I don’t grow most of the grasses listed below because I simply don’t have the room. But all are choices worth considering.
Miscanthus Gold Bar; Little Zebra
These two variegated cultivars, one gold and green, the other white and green, have horizontal stripes that cross at right angles to the growth. Wine red panicles in fall give them an intriguing look. Pair them with plain, dark companions to offset the busy foliage.
Calamagrostis (Feather Reed Grass) Karl Foerster
A “designer” grass that adds excellent texture to any setting. Karl Foerster is used extensively in urban layouts like street medians and walkway edges (and the High Line in NYC). It is perfect for tight spaces due to its narrow upright habit. This grass should be placed thoughtfully as it can come off looking rather stiff, but it’s a great choice when a strong vertical element is needed. It also works well in meadows provided it has similarly tall companions.
Calamagrostis brachytricha (Korean reed grass)
A fine choice for part shade, Korean reed grass grows just about anywhere and is hardy to zone 4. It sports large fluffy, pinkish-green to plum-grey bottlebrush inflorescences. A more manageable size at 4 x 3 feet than the miscanthus cultivars. A pretty grass with moody, muted overtones in fall. A good mixer.
Panicum virgatum ‘Shenandoah’ (Prairie Switchgrass)
This fast-growing native selection has green blades tinged with red during the summer, turning deep burgundy-bronze in the fall. Mature size is about 4 feet tall x 1.5 – 2 feet wide. Gorgeous with deep pink roses and conifers. An elegant choice for a pool area or deck.
Pennisetum orientale (Fountain Grass) Karley Rose; Hameln
Fountain-like Karley Rose is popular for its medium to robust size and rosy “foxtail” seedheads which form in midsummer and last all season. However, I found this cultivar to be rather floppy and not the best choice for borders. Hameln on the other hand, sports white foxtails in a short, compact package. This well behaved variety is perfect by the mailbox, in mixed beds or anywhere you want short sassy plumes. Both need full sun; amend clay and improve poorly drained sites.
Sporobolus heterolepis (Prairie Dropseed)
Despite its name, this graceful two-foot tall bunchgrass does not readily reseed. It forms delicate V-shaped sprays of panicles dangling on thread-like foliage. This medium-sized clumper is tough enough to stand up to snow, yet airy enough to fit in anywhere. Great for pathway edgings and urban settings as well as natural gardens. Prairie dropseed is a clever “see-through” choice that will soften hard lines and add a veiled look wherever you put it.
Petite grasses worth mentioning…
Two diminuitive choices that are particularly useful in suburbia are Festuca glauca (blue fescue) and Hakonecloa (Japanese hakone grass). Grow fescue for its neat, spiky blue color in sun to part shade, and hakone for lively chartreuse to deep green hues in part sun to dappled shade. Hakone turns beige to coppery-orange in late fall. Both are slow growing and sport dainty inflorescences with tidy habits. Ensure they have good drainage and adequate moisture in periods of high heat.
Using Grasses in the Landscape
Large cultivars can stand alone as single specimens or grouped. They look great next to rocks and boulders, substantive shrubs, among trees with interesting bark or bold forms, with evergreens like holly or other architectural plant forms that can stand up to their bulk. Grasses are especially useful when transitioning to a less manicured look, as urban dividers, as seasonal hedges, and wherever you need a super-low-care plant that can look after itself. They do spread over time, but are easily divided every few years in early spring.
Bold, contrasting silhouettes are especially effective. A few examples of possible companions:
- River birch; white birch
- Conifers
- Staghorn sumac
- Big-leaved tropicals like cannas
- Sedum Autumn Joy
- Angelica gigas
- Joe Pyeweed
- Tall daylilies (Hemerocallus); Trumpet lilies
- Landscape roses
- Berry-bearers like winterberry, pyracantha, beauty berry
- Rhododendron
- Hydrangea
- Eunonymous
To avoid a spotty look, smaller grasses look best in irregular or odd-numbered groupings. They mix well with perennials and annuals of similar height but different shapes. They help hide leggy stalks of taller plants, suppress weeds, and make terrific “buffer zones” between otherwise clashing colors.
Use them too, to break up and punctuate monotonous expanses of solid foliage or textures. Grasses are unsurpassed at softening the edges of paths, steps and decks, and likewise useful in hot xeric landscapes.
What are you waiting for! Grasses are lovely, low-care, and one of the garden’s best problem solvers. Do consider a few if you haven’t yet tried them.
