Ornamental grasses play an important role in the garden, adding structure and calming, neutral color. Many gardeners are afraid to use ornamental grasses because of stories they’ve heard about some grasses overtaking the garden and overflowing its borders. There certainly are rogue grasses, but there are many which are well-behaved and worthy of inclusion in the garden.
The use of non-invasive ornamental grasses is important because many grasses have escaped gardens and become nuisance plants in the wild. Some grasses have invaded natural meadow environments, choking out native grasses. Others choke natural wetlands and waterways.
A great benefit of using non-invasive grass species is knowing that your grass selection will not take over your garden. For example, pampas grass, an invasive variety in warm climates, quickly outgrows its space, chokes out other plants and can obscure large parts of a house. Ornamental grasses are light feeders and usually pest-free, so they use less fertilizer and chemicals, thereby reducing chemical saturation into groundwater.
Use non-invasive grasses to add structure to the garden. Their flowing sprays of blades and wispy flowers provide a backdrop for colorful annuals and perennials. Turning tan in fall, many grasses add shape and interest to the winter garden.
Non-invasive ornamental grasses are often native, clumping species. Among these are switch grass (Panicum sp.), offering long panicles of feathery flowers, and pink Muhlygrass (Muhlenbergia capillaries) with its global shape. Sweet flag (Acorus gramineus) is a native to North American wetlands. Other non-invasive favorites include blue fescue (Festuca glauca), with its tidy dense mounds of fine blue blades, and dwarf zebra grass (Miscanthus sinensis Little Zebra), which is well-behaved, despite the reputation of its larger cousins.
Most grasses require moist, well-drained soil. When planting, dig deeply, adding organic material. Add sand to heavy clay soil to loosen it. A few exceptions are sweet flag, which does best in standing water, and feather reed grass (Calamagrostis acutiflora), which tolerates heavy clay and sandy soils. Most ornamental grasses require full sun.