Gardening: Swaying ornamental grasses add movement, sound to garden

It took a trip to the Chicago Botanic Garden and its world-renowned prairie gardens before I began to appreciate ornamental grasses in the landscape. I couldn’t figure out why gardeners liked them so much.

We were at the CBG on a late afternoon August day as the sun was getting low in the sky and a reasonably strong breeze was blowing. Then I saw it; backlit blades of grasses in colors of green, yellow and red all moving gently in the wind. The garden was alive.

Many gardeners look to bright flowers or colorful leaves to create interest in their gardens. This approach ignores two other elements of nature found in the garden; light and motion. Ornamental grasses capture these elements beautifully. As I saw in the CBG grass gardens, backlit grasses glow in early or late light, providing a visual third dimension to a garden. As the sun moves, the light in the grasses changes, creating an entirely different view.

When the wind blows, ornamental grasses add movement and sound to the garden as they sway back in forth and rustle in the wind. This adds a unique dimension to the garden that makes it a much more interesting place to be.

Ornamental grasses come in sizes that range from the diminutive, 6-inch-tall blue fescues to the gigantic, 8-foot Miscanthus sinensis (and its 21 cultivars) and everything in between so there is a grass for every garden situation. They need full sun to grow well and take advantage of the light. Many of them are reasonably drought tolerant after they become established. Most of them need a well-drained soil high in organic matter. Check catalog descriptions and plant tags carefully for hardiness to our region.

The taller grasses are best planted on the east or west side of a garden and at the back of the bed where they can catch the sunlight. Shorter grasses can be planted in the foreground of beds. In the fall, many grasses turn beautiful shades of yellow, orange, bronze and even red. Left standing into the winter, they turn a straw color and continue to add winter interest until the heavy snow takes them down.

Ornamental grasses are easy to care for. They aren’t prone to disease or insect damage, are long-lived and are not fussy about fertilizer. The only regular care they need is to be cut to the ground in late winter before the new growth starts in late April. Bunch grasses such as blue oat grass, blue fescue, sedges and rushes don’t need to be cut back and are easily cleaned up by combing out old foliage with a rake or your hands.

Beyond the garden, ornamental grasses can be used in indoor flower arrangements and as winter decoration in outdoor pots. The seed heads can be woven into wreathes at Christmas. If you choose to cut the grasses down in the fall, the stems can be used as winter mulch to protect other plants in the garden from the cold.