Companion Plants for Ornamental Grasses
by Diane Linsley
With ornamental grasses becoming more popular every year, gardeners are trying to think of ways to integrate these lovely plants into their gardens. What are the best companion plants for ornamental grasses? Will maiden grass mix with petunias?
First, consider the concept of scale. Grasses come in many sizes, from small mounds of blue fescue to towering plumes of Indian grass. Companion plants should be scaled appropriately. But that doesn't mean you should only plant 6-foot-tall flowers with your 6-foot-tall miscanthus. On the contrary, different heights give the garden a pleasing, layered look.
Another concept to consider is balance: Several small plants may be needed to balance one large plant. Don't give in to the temptation to simply plant one of everything. If you are gardening on a tight budget, choose self-sowing annuals and first-year flowering perennials to fill in quickly. Also consider the season of bloom. Most ornamental grasses bloom in late summer to fall. Naturally, they look best paired with late-blooming flowers. But we want our gardens to look great all season. Try some early-blooming flowers and bulbs. Ornamental grasses can be used to hide dying bulb foliage.
Plan for a winter landscape. Most grasses look nice throughout winter, until they get buried by a heavy snowfall. Consider adding needled evergreens, weather-resistant garden ornaments, and flowers with attractive seed heads. Think of the winter garden as a gigantic, dried flower arrangement. Small trees and shrubs provide year-round structure (referred to as "the bones of the garden").
Finally, ornamental grasses look good with each other! Even a small garden has room for several well-placed grasses. You could combine one large Miscanthus with two or three medium-size grasses. Add some colorful flowers, and you'll have a garden that looks like it was designed by a famous landscaper. Aim for different heights, textures and colors.
Now for some flowering companion plants. I've separated these into groups of tall, medium and short flowers to go with different sizes of ornamental grasses, but feel free to mix them up. For example, you can use tall grasses as a backdrop for medium-height grasses and flowers. Then place the short ones at the front of the border.
Remember to give grasses and perennials room to grow. You can fill in the gaps with annuals to make the garden look lush until the perennials reach their mature sizes.
Companion Plants for Tall Grasses
These flowers look good with grasses that grow 5-7 feet tall like Miscanthus and Feather Reed Grass.
Aster azureus -- Fall-blooming perennial with a cloud of blue flowers. Cleome -- Tall stems of pink, purple or white flowers. Annual. Cosmos -- Popular annual in a variety of colors and sizes. Echinacea (Purple Coneflower) -- A classic companion plant. Native. Liatris (Blazing Star) -- A vertical accent with purple flowers. Native.
Companion Plants for Medium-Size Grasses
Try these with grasses that grow 2-4 feet tall like Big Bluestem, Little Bluestem, Pennisetum, Mexican Feather Grass, Northern Sea Oats and Switch Grass. Coreopsis -- Golden-yellow or brick red flowers. Annual wildflower. Dalea purpurea -- Interesting purple flowers. Native perennial wildflower. Geum chiloense -- Scarlet-red or yellow flowers. Long-blooming perennial. Penstemon -- Blooms in early summer. Foliage and seed pods are nice in fall. Rudbeckia hirta -- Annual or short-lived perennial with warm colored flowers. Salvia -- Perennials and annuals in various colors. Zinnia -- Late summer-blooming annual in a wide range of colors.
Companion Plants for Short Grasses
These flowers are useful for edging, or for planting in the rock garden, along with grasses that grow 1-2' tall like Blue Fescue, Prairie Dropseed and Sedge.
Viola cornuta -- Annual or short-lived perennial for filling in the gaps.
Gardening with Grasses by Michael King and Piet Oudolf
Designing with Plants by Piet Oudolf and Noel Kingsbury