Native Long Grasses Offer Variety for Summer Gardens
For most people, the words “grass” and “lawn” go together like mac and cheese. Yet in the month of August, it’s easy to see that some grasses are anything but lawn-like. Next to some of our highways, for instance, a short grass produces drifts of soft purple that rival any flowering plant. At woodland edges, tall airy seed heads and red-tinged leaves wave in the wind. At the beach, strong stalks rise above the pure sand.
These are not your grandfather’s lawn grasses.
In fact, lawn grasses are just a few members of an enormous family of beautiful plants that, according to some experts, cover as much as 40 percent of the earth’s land surface. Many lawn owners are surprised to learn that local lawn grasses, including perennial rye, fescue, bluegrass, and bentgrass, are not native.
But other grasses evolved here over thousands of years and are native. Low-growing purple love grass (Eragrostis spectabilis) is blossoming along Route 395. The airy tops of switchgrass (Panicum virgatum) decorate wet fields and woodland edges. American beach grass (Ammophila brevigulata) reduces beach erosion. In the fields at Harkness State Park, little blue stem (Schizachyrium scoparium) and Indiangrass (Sorghastrum nutans) offer food and habitat for birds.
New Englanders can be forgiven if we are not very grass aware. Our climate and soil favor trees and shrubs, not grasslands. Even before our area became so intensely developed, most native grasses were opportunistic invaders. They sprung up in spaces opened by fires, lightning, or beaver activity. As time passed, woody plants took over from the grasses. Grass seeds lay dormant until new openings occurred.
How can plants in the same family look and act so differently? There are three major reasons.
Warm-season vs. cool-season grasses: Lawn grasses are of the cool-season variety. They look best in spring and fall, but naturally go brown in midsummer. One reason we plant lawns in September and October is that cool-season grasses have a fall growth spurt.
Purple love grass, Indiangrass, and little blue stem, on the other hand, are warm-season plants. They peak during July, August, and September and make great ornamentals in summer gardens.
Just to make matters a bit confusing, though, there are some beautiful cool-season ornamental grasses. The popular Elijah blue fescue (Festuca glauca), is a cool-season ornamental commonly sold at garden centers. Among the tall grasses, bluejoint grass (Calamagrostis canadensis) is a handsome native of the cool-season variety.
Bunching grasses vs. spreaders: Grasses have two basic types of roots. The roots of Kentucky bluegrass and bentgrass, two common kinds of lawn grass, spread horizontally underground and form mats. Fescue and perennial ryegrass are bunching grasses that tend to stay in place. When bunching grasses and spreaders are planted together in a lawn, and conditions are optimal, they can form a dense carpet. (That’s one reason lawn seed is usually sold as a mix of plants, not a single variety.)
Almost all ornamental and pasture grasses are bunching types, though there are exceptions such as American beach grass.
Furthermore, warm season grasses are phenomenal sources of food and habitat for birds, pollinators, and other critters. In fact, the meadow grasses at Harkness and other parks are managed by the Wildlife Division of the Department of Energy & Environmental Protection. Do you feed birds? You can skip the feeders if you allow native grasses to stand through the winter. Cut them once per year in March.
Shallow-roots vs. deep: It may come as no surprise that spreading grasses tend to have shallow roots, while bunching grass goes deep. Where Kentucky blue grass might have six-inch roots, Indiangrass might penetrate six feet or more. Deep-rooted bunching grasses are excellent additions to slopes or other areas prone to erosion.
All grasses—bunchers and spreaders, warm-season and cool-season—have some important features in common, too. They all grow from the base, not from stems. That’s why we can mow grass without killing it. That’s why grasses rarely get as tall as even the smallest trees. In addition, grass leaves are full of water and nutrients. That’s why grasses are the main food source for many animals—and also why we should never bag mowed grass. Leave it on the lawn or compost it to take advantage of its nutrients.
As you drive our region over the next few weeks, keep your eyes open for our beautiful native grasses. They are at their very best right now.
Kathy Connolly is a landscape designer, writer, and speaker from Old Saybrook. See her speaking schedule or contact her through her website: www.SpeakingofLandscapes.com.