Fall is the season when warm-season ornamental grasses get their turn in the spotlight. They spend the summer playing a supporting role in the landscape – screening views, adding texture to borders, and providing a backdrop for annuals and perennials. Grasses patiently wait for frost to give flowers the hook and cast them in the garden’s starring role.
One of my favorite ornamental grasses is Panicum virgatum, commonly called switchgrass. Panicum virgatum once grew in tallgrass prairies with other natives like bluestem, indiangrass, black-eyed Susan and coneflowers.
Switchgrass offers three seasons of interest to the landscape. Sweet and airy pink-tinted flowers bloom in summer becoming beige seed heads in fall. In winter, its rigid, upright form adds winter interest for gardeners while providing food and protective refuge for wildlife.
A warm-season grass, Panicum virgatum waits until temperatures warm in mid spring before actively beginning to grow. It grows best in average garden soil in full sun. Switchgrass is quite adaptable to a range of soils, but would select moist earth if given its choice. In these conditions it stands upright, but it may be lax if the soil is too rich or it is grown in too much shade.
Switchgrass requires very little maintenance. Cut it back in early spring before new growth begins. Remove unwanted seedlings before they develop deep root systems. Pretty easy, right?
There are many cultivars of switchgrass available at local garden centers. Dallas Blues boasts wide, baby blue leaves. It grows six to eight feet tall and three feet wide. Use Dallas Blues to block unwanted views or plant it with tall late-blooming perennials like Joe-Pye weed.
The metallic blue leaf blades of Heavy Metal reach a bit more than three feet tall. Its delicate, pink-tinted flowers waft a foot or more above the foliage. Heavy Metal is lovely planted with summer-blooming perennials.
Northwind was discovered by Roy Diblik of Northwind Perennial Farm in Lake Geneva, Wisconsin. It grows straight as a soldier five to six feet tall and two to three feet wide. Its deep green foliage turns golden yellow in fall. Northwind is an excellent choice for hedging or using as an exclamation point in a mixed shrub border.
The foliage of Ruby Ribbons begins blue green in spring before sporting ruby red hues with summer heat. This variety is smaller – just two to three feet tall and wide. It shows off its reddish-pink flower panicles in September. Ruby Ribbons is spectacular planted in containers with summer and fall-flowering annuals.
Thundercloud is a very large selection. Strong stems displaying blue green leaves grow up to eight feet tall and three feet wide. Pink-tinged flowers appear just above the foliage in late summer. Use Thundercloud as a specimen plant in the landscape.
Panicum virgatum offers much and asks little in return. Plan to add at least one type to your landscape next spring. Garden with me!