Let’s Talk Ornamental Grasses

Let’s Talk Ornamental Grasses

Grass trial garden at North Creek Nurseries.  ©2020 North Creek Nurseries.

Don’t overlook ornamental grasses when you plant. There are many reasons to utilize them in the landscape. They’re easy to grow, durable, and long-lived. They’re also among the most deer-resistant plants (I promise I’m not making that up). They come in many sizes, growth habits, and colors, and bring form and character to the garden that other plants don’t provide.

Sapphire Blue Oat Grass (Helictotrichon sempervirens ‘Sapphire’)

If you don’t use ornamental grasses, I’d say you’re missing out on a key component of a well-balanced landscape.

Grasses have a different physiological structure and growing habit than most other garden plants. Their foliage brings vertical dimension to the garden due to their form and bring motion with how they move in the wind. The inflorescences (flower structures) of grasses provide a further array of exciting forms and texture in summer and fall. I love seeing grasses sway on a breezy day; perhaps the feeling is subconsciously reminiscent of a bygone era when our ancestors lived in the savannah, or our pioneer forefathers travelled the American prairie. They’re something soothing about it.

Cultural Conditions

Most grasses do best full sun, although some will grow in partial sun. There are also a few shade grasses. Most appreciate well-drained soil, with many being drought tolerant once established. Some grasses will also tolerate clay soil, road salt, and even brief periods of flooding.
One of my goals as a nurseryman is to help people go beyond the basic “bushes ‘n mulch” mindset which is outdated and incomplete. Utilizing ornamental grasses is a good way to start.

The Popular 3 Grasses

Calamagrostis ‘Karl Foerster’

Currently, the most widely planted grasses are Maiden grass, Karl Foerster grass, and Fountain grass.

M. sinensis ‘NCMS2B’ Bandwidth

The most popular Maiden grass (Miscanthus sinensis) might be ‘Zebra’, which has gold bands across the green foliage reminding one of Zebra stripes. It’s beautiful, but I recommend the new cultivar ‘Bandwidth’ which is smaller and, more importantly, sterile. Other sterile or nearly sterile forms are ‘Scout’, ‘Cabaret’, and Giant Maiden Grass (Miscanthus x giganteus).

‘Karl Foerster’ is one of several cultivars of Feather Reed grass (Calamagrostis ‘Karl Foerster’). It was the first ornamental grass to win the Perennial Plant of the Year award (2001) and is still widely planted today. This upright grass matures at 3-4 feet high, making it a great addition to foundation plantings. The attractive inflorescence (flowers) emerges earlier in summer than most ornamental grasses, a definite plus.

Fountain grass (Pennisetum alopecuriodes) is named after its arching habit which indeed resembles a fountain. This grass is favored because of its smaller size and dramatic “fuzzy” inflorescence. You might recognize Purple Fountain grass which is popular annual. The cultivars “Hameln”, “Piglet” and “Little Bunny”, all of which average at 1-2 feet high, are all perennial.

My Favorite 3 Grasses

P. virgatum Prairie Winds® ‘Apache Rose’

While the above three grasses are perhaps the most familiar, I usually suggest my favorites to customers. My favorites ornamental grasses are Switch grass, Little Bluestem, and Prairie Dropseed.

S. heterlopsis

Switch grass (Panicum virgatum) is a medium to large-sized ornamental grass, like Maiden grass, although its inflorescence is lighter and airier. This might be the most adaptable grass species in cultivation because it’s both drought tolerant and mildly wet-tolerant. This species is also native to the mid-Atlantic and provides habitat for Skipper butterflies, fireflies, and nesting material for songbirds.

There are many cultivated varieties of Switch grass. Many are blue in color, like ‘Dallas Blues’ and ‘Heavy Metal.’ Others have red-tinged foliage such as “Shenandoah” and “Apache Rose.” Some open and “fountain out” by the end of summer, and others, such as “Northwind” are very rigid and upright. I grow the cultivar ‘Northwind’ in my garden and I love it! This species offers a lot of choices.

S. scopularium Prairie Winds® ‘Blue Paradise’

Little Bluestem (Schizachrium scopularium) is a small, upright grass that has beautiful blue foliage in spring and summer, and stunning red-orange tones in fall. Like Switch grass, Little Bluestem is drought tolerant and salt tolerant.

Prairie Dropseed (Heterlopsis sporobulus) is a small grass with a graceful, arching habit and modest inflorescence. Long-lived and super tough, Prairie dropseed will need very little (if any) supplemental water once established. I planted several in my garden this year and I’m excited to see them establish and grow. This is a great native alternative to smaller forms of Fountain grass (P. alopecuriodes).

For more information on my favorite grasses, check these links.

https://www.gardenia.net/plants/plant-family/panicum_–_switch-grasses

https://www.gardenia.net/plant/schizachyrium-scoparium

https://www.gardenia.net/plant/sporobolus-heterolepis-prairie-dropseed

“Let’s Talk Maintenance”

Big Blustem cultivar ‘Blackhawks’ (Andropogon gerardii ‘Blackhawks’)

I’d argue ornamental grasses require less maintenance than most landscape plants. Other than watering the first season so they establish, the dry foliage simply needs trimmed down once a year. That’s it. Some have told me that’s a lot of work and my usual thought is, “How much time do you spend mowing your lawn every year?” Probably a lot more.

Leaving your grasses up in winter provides winter beauty. ©2020 North Creek Nurseries.

If you have a sharp set of shears, cutting down dried grass stems is easy. If they’re not sharp, go sharpen them. You can also use a weed whacker. I also don’t bother to collect the foliage and throw it away (more work). I cut the foliage up and leave it on my beds as a natural mulch and for nesting material for birds– remember, the landscape is outside and doesn’t need to mimic the tidiness of the indoors.

Many cut down their grasses in fall and I always wonder why. Part of what makes ornamental grasses special is the winter interest they provide. Many pollinators and fireflies also take refuge in them for the winter so resist the urge to scalp them in fall and only cut them down when new foliage begins to emerge from the base in spring.

Fellow employee Jess gives this recommendation on cutting your grasses back: If it’s a variety that’s taller than 3 feet, cut it back to 3-4 inches from the crown. They can get a flat top haircut.  If it’s a variety that’s shorter than 3 feet, cut it back to an inch from the crown – and give it a bowl cut. A flat top cut might damage the crown of short grasses so a proper trim should make it look like a little round “hedgehog.”

Division

The great thing about medium to larger grasses is that well-established plants can be divided into sections and replanted in other areas of the landscape. This also helps with size reduction if you think they are getting too large for where they are. If you decide to divide your grass, do so when temperatures are cool; early to mid-spring or early fall is best.

Grasses for Shade

Japanese Forest Grass (H. macra ‘Aureola’)

Japanese Forest Grass (Hakonechloa macra), usually available through the cultivars “All Gold” and “Aureola”, is a great plant to brighten up and enhance any shade garden.

Tufted Hair Grass (Deschampsia cespitosa) is a shorter grass, like Prairie Dropseed in appearance, that works great for a dappled sun or partly sunny area.

While not true grasses, sedges (Carex spp.) grow like low grasses in the landscape. There are many sedges and they come in an assortment of colors – green, blue, chartreuse, and variegated. Pennsylvania sedge (Carex pennsylvannica) is a great choice for dry, shady areas such as under a mature tree or near the eaves of a house.

Wet Spaces

Most ornamental grasses don’t appreciate wet areas. While Switch grass is wet tolerant to an extent, it may not be the best plant for permanently wet areas. For these areas, try a rush (Juncus spp.) instead. Rushes aren’t true grasses, but they function like grasses in form and habit in the landscape (plus some are evergreen). We sometimes carry Common Rush (Juncus effusus) which some might recognize through the cultivar “Corkscrew” (J. effusus ‘Spiralis’).

Plant Some Grasses!

Pink Muhly Grass (Muhlenbergia capillaris) ©2020 North Creek Nurseries.

Ornamental grasses are beautiful. They are inexpensive, hardy, and highly deer resistant. Their fibrous roots are excellent for stabilizing hillsides or holding soil by the street curb. They come in many different sizes, large and small so finding a spot for one should be easy. The list of advantages could go on.

Here are some other grasses we usually have in stock:

Leaving the dried foliage of grasses through winter, such as on native Northern Sea Oats (Chasmanthium latifolium) provides winter interest, food for birds, and shelter for pollinators. ©2020 North Creek Nurseries.

Northern Sea Oats https://www.gardenia.net/plant/chasmanthium-latifolium-northern-sea-oats

Pink Muhly Grass https://www.gardenia.net/plant/muhlenbergia-capillaris-pink-muhly-grass

Big Bluestem https://www.gardenia.net/plant/andropogon-gerardii-blackhawks

Blue Oat Grass https://www.gardenia.net/plant/helictotrichon-sempervirens-blue-oat-grass

Sweet Flag https://www.gardenia.net/plant/acorus-calamus-variegatus

Purple Moore Grass https://www.gardenia.net/plant/molinia-caerulea-subsp-arundinacea-moor-grass

If you were skeptical before, I hope I’ve convinced you. Late summer and early fall are when grasses are in peak season (i.e. flowering) so now is a great time to check out our selection. Hope to see you soon!

Photo credits to North Creek Nurseries, Perennial Farm, and Proven Winners.