Using Ornamental Grasses in Your Garden Design

I can’t imagine designing a garden without tucking at least a few kinds of ornamental grasses among the traditional flowers, shrubs and trees. For one thing, they’re generally not very thirsty plants, nor are they fussy about soil conditions. What's more, ornamental grasses are tolerant of most diseases and pests, deer and rabbits included. What’s not to love about a plant as rugged as that?!

Sized to Suit Any Space

Grasses also come in just about every size and color, making them ideal candidates to use throughout a garden no matter its dimensions. Check out these varied options:

Black mondo grass grows just six inches high.

Make a dramatic statement at the front of the border with shiny black mondo grass (Ophiopogon planiscapus ‘Nigrescens’; USDA Zones 6–9. It slowly grows to only six inches high.

Blue oat grass makes a tidy two-foot dome.

For the middle of the border, consider the steely color of blue oat grass (Helictotrichon sempervirens; Zones 4–8), which grows to a manageable two- to three-foot dome.

Purple fountain grass can be five feet tall or higher.

For the back of the border, consider the deep burgundy foliage of purple fountain grass (Pennisetum setaceum ‘Rubrum’; Zones 9–10), often towering over five feet tall.

In addition to the colors provided by the foliage itself, most grasses “flower” (taking the form of graceful inflorescence). These often last 8 to 10 weeks and add additional color and height to the grass.

Ruby grass blooms in pink.

For example, in the late spring delicate wands of pomegranate-pink inflorescences double the height of the normally 12-inch ruby grass (Melinis nerviglumis ‘Pink Crystals’; Zones 8–10), which has blue-green foliage.

The familiar golden wands of 'Karl Foerster' reed grass.

The midsize feather reed grass (Calamagrostis xacutiflora ‘Karl Foerster’; Zones 4–9) puts on a late-summer show when its tidy two-foot green foliage is transformed with towering four-foot-high stalks of golden, feather-like “flowers.”

Late-Season Saviors

Grasses are one of my favorite plants to use in the garden for late-season interest. Their fine foliage catches fall’s slanted light better than any plant I can think of. They glow in the late afternoon as if lit from within. And should there be a soft breeze, they’ll gently sway, providing another much-needed design element—movement.

Sea oats provide fodder for birds in winter.

When winter hits, the grasses’ inflorescences turn tawny shades of tan and copper, I leave them on the plant for as long as possible. The seed heads not only provide much-needed winter interest, but many grasses, such as prairie dropseed (Sporobolus heterolepis; Zones 3–9) and northern sea oats (Chasmanthium latifolium; Zones 3–8), help sustain birds hunting for seeds.

Design Tip: Pot It Up

One of my favorite ways to elevate the status of an ornamental grass is to place it in an elegant container and nestle that within the garden bed. Instead of filling the container with a complex mix of perennials, consider the “one-plant-per-pot” method, focusing the attention on a spectacular grass. This unexpected twist not only adds unique personality to your garden, but the grass’s textured foliage gets the spotlight that it deserves.