The Spring garden usually consists of smaller growing plants; those that wake up early, grow and bloom with the cool conditions of the start of the growing season. The fall is the time for the big plants to take center stage, having had the whole summer to reach flowering size. Many of the most dramatic plants in the late season garden would have to be the ornamental grasses. With their large size and interesting flowering spikes, these grasses have no equal when it comes to reflecting the glow of sunlight late in the day. And the grace of their swaying stems in the slightest breeze brings movement to the landscape.
The Warm and Cool of It
All of the ornamental grasses are good candidates for fall planting and you'll get a head start on next spring. Know that the warm season growers won't show a lot of top growth, as their energies will be spent growing roots. The cool season growers will show both above and below ground growth.
Grasses are loosely divided between cool season growers and warm season growers.
The cool season clan includes:
When considering the addition of warm season grasses to your landscape, it's nice to know that they are outstanding companion plants to a variety of herbaceous perennials and smaller flowering shrubs. Their presence with perennials immediately captures your attention.
The warm season growers include many of our native prairie grasses, such as:
When planted with smaller growing shrubs such as summer blooming Blue Mist Spirea (Caryopteris) and fall blooming Rabbit Brush (Chysothamnus), Maiden Hair Grass is especially showy. In fact, many of the large growing ornamental grasses are great shrub companions for creating an interesting but very low care landscape. They are a great choice for the casual gardener.
Care of Ornamental Grasses
Don't cut them back in the fall! The most common mistake I see with ornamental grasses happens when they're cut back in fall as part of fall garden clean-up. This robs you of their beauty over the fall and winter months which is a big part of their usefulness, especially in climates with long, dreary winters.
For warm season growers, wait until mid-spring and cut them back HARD (leaving only 2-4" inches above ground).
For cool season growers, trim off the faded seed heads and comb out the foliage to rid it of brown foliage. But whenever possible avoid cutting them back near ground level like their warm season cousins.
Fertilize in mid-fall with a top dressing of Yum Yum Mix Winterizer and compost around the base of the grass. Scratch it in, re-apply some mulch and water thoroughly.