Designing with Ornamental Grasses

By Indigo Deany

For a moment, let’s turn our gardener gazes towards cinema. Suppose that in the garden, your flowers are Frodo, your trees are Gandalf, and your veggies are Aragorn, Gimli, and Legolas. Perhaps bindweed is Smeagol. For those of you unfamiliar with the universe of The Lord of the Rings, these comprise your central cast of characters: they are each undeniable stars in their own right. Amidst a small cadre of fans, however, you will find people who would go down swinging for the glory of a supporting character: Samwise Gamgee, arguably the true hero of the entire series. He is grounded, reliable, pure of heart, and brings beauty and consistency to an otherwise sprawling, complicated story. In the garden, ornamental grasses are our Samwise.

It is easy to forget just how instrumental ornamental grasses are in any garden or landscape design. Ecologically, they provide myriad benefits to the landscape, both above and below ground. The foliage and seed heads remain on the plants through the winter, providing essential habitats for birds, insects, and other creatures. Below the surface, the benefits of grasses are astounding. While the root systems of ornamental grasses can vary in size depending on the species, many of them reach deep down into the soil. This allows for smaller root systems of neighboring plants to access nutrients from the soil in a different “zone of depth.” Less competition for nutrients in the soil results in healthier plants all around! These extensive roots assist massively with erosion control, holding sediment in place. Erosion control has many positive effects, including water retention on your site as well as soil health rehabilitation. Additionally, grass root systems are very fibrous, which benefits water regulation in both dry and wet gardens. In a dry garden, their extensive, web-like roots hold onto and draw water down deep into the soil, giving nearby plants that have more shallow root systems a chance to drink before water evaporates from the topsoil or runs offsite. In gardens prone to flooding, rain gardens, or swales, grasses pull the water down from the surface and store it in the soil, which results in less flooding on the surface and less runoff water waste. 

Ornamental grasses are far from being mere machines, however. The grace that they bring to the garden is undeniable. When planted on the east side of your garden, the morning sun catches the silhouette of the blades or seed heads and gilds them in silver. Planted on the west of your garden, the sunset sets their silhouettes on fire. The interplay that ornamentals have with light is unlike any other element in your garden, and this is essential for bringing dimension to your space. Further, the sound of the wind through your grasses is calming, and is operative in creating a meditation or sensory garden. The sound can even act as an ambient cushion to soften the street noise outside your home. The movement that the wind provides through grasses is a foundational design element, as grasses will gently wave even while other plants remain still. Much like the shivering leaves on a quaking aspen, the movement of ornamental grasses is hypnotizing and beautiful.

Functionally, ornamentals can be used as screens, backdrops, ground covers, or for winter interest. Often, when a garden feels empty despite its flowers and trees, it is missing the cohesive element of ornamental grass. Grasses are calm enough on the eye that they can be used throughout your landscape to fill in gaps or create repetition throughout space. Short ornamental grasses can be used to soften the edges of walkways or other borders. Tall ones can be used as a screen or backdrop to create privacy and an organic anchor behind your flower beds. For a fantastic example of using ornamental grasses for erosion control, head to the northernmost tip of Horsetooth Dam: the entire slope of that project is planted with Little Bluestem, a shortgrass prairie native that turns a glowy, pale burgundy in the fall. 

For height, consider planting Switchgrass (Panicum) or Maiden Grass (Miscanthus). Panicum ‘Shenandoah’ reaches 5’ tall and turns a deep red in the autumn, appearing truly molten when backlit by the rising or setting sun. Miscanthus ‘Silberfeder’ produces silky, silvery seed heads in late summer, providing graceful ripples of silver that enhance a cool-toned or moon garden. Bouteloua ‘Blonde Ambition’ produces vivacious, celebratory flags of seed heads atop its 2-3’ cool blue-green foliage. Prairie Dropseed (Sporobolus heterolepis) is a silky soft, beautifully-textured native grass that is stunning when planted en masse. This is a great species for transitioning the edge of your lawn into a perennial bed or walkway.

Whatever style or function you want in your landscape, ornamental grasses are an essential component of garden design. We are lucky enough to live in or near the staggering, stunning landscape of the American shortgrass prairie, which means that we have the privilege of access to countless native grasses that are in cultivation. Additionally, our extremely talented team works hard to source a broad selection of ornamentals from around the world that can work in your space. These gentle, stalwart plants very well may become your favorite character in your garden.

Originally published on June 3rd, 2024.