Ornamental grasses are becoming as much a hallmark of the autumn landscape as the changing colours of the leaves on trees and shrubs. I love how grasses have become so dominant in the fall garden. For instance, the row of Feather Reed Grass (Calamagrostis acutiflora “Karl Foerster”) along the south side of the Events Centre in Penticton never fails to impress me on my daily commute from Summerland. Another grass that I’ve come to admire is Panicum virgatum, or Switch Grass. The cultivars of this North American prairie native offer changing foliage colour as temperatures drop, delicate panicles of blooms that quiver in the slightest of breezes and easy care. If ever a plant was made for fall gardens this is it!
NUTS AND BOLTS
Switch Grass is a warm-season grass, so it begins to grow later in the spring. Once the heat arrives it rapidly increases in size, producing pink or red-tinged flower heads beginning in late July. Varieties will range in size from 1.2 to 2.4 metres tall, though most of cultivars you see available don’t grow much more than 1.5 metres tall. Panicum was at one time a dominant grass of the American prairies, so a sunny, open location suits them best. It will spread slowly by rhizomes but will never pose a problem in a garden. Plants will tolerate drier soils after they become established but regular moisture is appreciated.
A mass of three to five plants gives the best effect, as the airy panicles of flowers are much more effective when there are numbers; a single specimen gets easily lost. Plant Switch Grass where you can see the late summer and autumn sun shining through the flowers. The effect is magical. Watching the plants move in the very slightest of breezes is also an enjoyable pastime, so situate accordingly. There are a host of cultivars available, some have blue foliage which turns yellow in fall; others start out with green foliage which then becomes red as the weather begins to cool.