As the use of native perennial flowers in gardens continues to grow in popularity, using native grasses for ornamental designs has also become a popular choice. While often easy to maintain and essentially pest free native grasses add texture, diversity, and color to flower beds long after flowers have gone dormant in winter. Organized by size, specific environmental conditions, and use – many varieties exist offering a gardener a long list of options for any situation.
When taking size into consideration native grasses are organized into three distinct sizes with some variation – small (below 1 foot), medium (around 1 to 3 feet), and large (much taller than 3 feet). Smaller varieties such as Bulbous Oat Grass (Arrhenatherum elatius) or Prairie Dropseed (Sporobolus heterolepis) are good choices for low growing ground covers. Little Blue Stem (Schizachyrium scoparium) and Bottle Brush (Elymus hystrix) work well in intermediate areas of a bed to fill in open space. While large varieties such as Switch Grass (Panicum virgatum), Big Blue Stem (Andropogon gerardii), and Indiangrass (Sorghastrum nutans) can stand alone on perennial borders and be used as wind breaks.
Selecting a grass for the right conditions is a key factor to how successful the plants will be. Environmental conditions to keep in mind include how wet or dry the soil will be and how much sun or shade the area will receive on an average basis. Common Rush (Juncus effuses) thrive in wet, bog-like conditions and can be found as an evergreen year-round along roadside ditches where water commonly exists. Tufted Hair Grass (Deschampsia caespitosa) is a resilient grass that is able to flourish even when drought occurs in the height of summer.
Little Blue Stem (Schizachyrium scoparium) – shown in bottom left – works well in intermediate areas of a bed to fill in open space. Pink Muhley Grass (Muhlenbergia capillaris) – shown on top right – features striking plumes of color and texture making it a distinct choice for bouquet fillers or accents in flower arrangements.
Many perennial grasses have attractive color, flowers, and interesting seed head designs making them great specimens for fresh and dried arrangements. Northern Sea Oats (Chasmanthium latifolium) and Pink Muhley Grass (Muhlenbergia capillaris) are characteristically ornamental with striking plumes of color and texture making them distinct choices for bouquet fillers or accents in flower arrangements.
After adding grasses to a garden the most common question is when to cut back the stalks before the next years new growth occurs. People generally choose to cut back grasses in either the fall after the first frost occurs or in the spring before the last frost occurs. The real answer to this question takes into account the home owner or businesses personal decision. Since it is more of an aesthetic choice than anything, as long as trimming does not occur within the height of the growing season—April through September—the grasses will survive without stress. Several arguments exist for either of the two situations.
If left uncut through winter, varieties with distinctive seed heads or winter color can add a bit of beauty to the garden in the deep winter months while larger varieties can provide food for birds and add shelter for wildlife to nest and hide from the cold. Leaving grasses through winter until temperatures are above single digits can also protect the plant’s center from freezing causing dramatic plant loss.
Cutting grasses back in the fall allows homeowners and landscape companies more freedom in the spring to have more time for other projects (if we are lucky enough to have an early spring). Some varieties hold their form well, while others flop over at the first heavy snow. Early maintenance can help to avoid this unkempt look adding an interesting appearance to gardens. With fresh mulch the cut back design can be just as beautiful as leaving the grasses up. As stated before, it’s all about personal choice.
Ornamental grasses divided and ready for spring planting.
Whenever grasses are cut back it is also the perfect time to divide and transplant. As grasses grow into large clumps they can be cut into smaller sections and then replanted creating an endless supply of plants. Dividing can also help older plants from dying out in the center and aids in the overall health of the plant. To divide, simply trim off the old stalks, dig up a desired clump after it has reached the size of a dinner plate or larger, and cut the clump into smaller sections leaving plenty of roots. Either plant the smaller sections immediately or pot them up until they reach a desired size – making sure to keep the roots from drying out with lots of water and shade.
For more information and a detailed description on types of grasses to choose visit the following websites:
Story and photo by Nathan Strange, Zone Gardener Nathan joined The Parklands staff in 2014 as a Gardener and currently oversees the areas around the Egg Lawn, the Pollination Garden at PNC Achievement Center/Gheens Foundation Lodge, and manages the collection and propagation of native plants within the park. While attending University of Kentucky for a degree in Natural Resource Conservation & Management, Nathan worked as a naturalist at Natural Bridge State Resort Park and as a field technician for Floracliff Nature Sanctuary – specializing in program development, native plant alternatives, and invasive species removal. In 2011, Nathan published “A Guide to the Knobstone Trail: Indiana’s Longest Footpath” with Indiana University Press – representing three years of independent research while highlighting his love for hiking and the outdoors.