Benefits of native grasses in urban landscaping

By Susan Harkins and Jonathan Kubesch

Prairie dropseed ((Sporobolus heterolepis). Photo: Lady Bird Johnson Wildflower Center

Years ago, when I started planting native species for wildlife, I planted trees and flowers. My commitment to natives is strong, and I’ve restored nearly half of my property with native species of trees, shrubs, and flowering plants. Only one thing is missing, and that’s native grasses. Native grasslands and savannah are part of Kentucky’s rich natural heritage.

Native grasses provide a showy, functional addition to the backyard, the field corner, or the fencerow. At the time, I didn’t know the many benefits for our native wildlife that native grasses offer.

Improve ecosystem function

At the heart of every successful garden is the right soil. Regardless of your soil type, keeping topsoil and runoff in your urban yard can be a challenge. Traditional lawns can prevent erosion and runoff under ideal conditions, but native landscaping protects soil and water from more extreme weather events with fewer inputs. Some people plant rain gardens to prevent run-off but native grasses are also good at holding soil in place thanks to their long, fibrous, strong roots. Grasses help build organic matter and increase water infiltration. It doesn’t hurt that they require little maintenance and that they’re beautiful.

Native grasses also have reduced soil fertility requirements in comparison to many introduced species. Work from Kentucky and Tennessee suggests that most soils can support these grasses with modest additions of P and K (Potassium and Phosphorus) both of which can come from compost or the regular breakdown of organic matter in the yard. Native grasses can make a yard more of a closed loop for cycling nutrients.

Improve habitat

Until I started following the Kentucky Department of Fish & Wildlife Resources program on how native grasses benefit songbirds, I had no idea how important native grasses are to wildlife. I was aware of how game birds, such as quail, benefit from native grasses, but almost everything benefits from native grasses. Songbirds benefit from the insects, grass seed, and habitat available in native grasses. The open space at the ground level allows baby birds to move freely and the cover of native grasses provides protection from predators.

Eastern bottlebrush (Elymus hystrix L.). Photo Lady Bird Johnson Wildflower Center

Native grasses are host to a number of butterfly and moth species in their larval stage. Rebuilding these populations will help rebuild the bird populations as many feed caterpillars to the young. While not every yard might produce a full ecosystem, there’s research underway at Virginia Tech about how to use native grasses and wildflowers to produce bee-friendly beef.

Establishing native grasses

Converting current lawns or garden space to native grasses requires some planning and preparation. The easiest areas to convert towards native grasses are formerly wooded areas or cropland. In subdivisions, this might be a new home. Old pastures and lawns can be difficult to convert to native grasses because of the existing weed issues present. That said, attention to detail can make areas work for native grasses.

Start with a soil test from the University of Kentucky to get a baseline for any fertility adjustments. Killing existing vegetation needs to be as effective as possible. Research across the mid-South currently leans towards a “spray-smother-spray” approach where the current vegetation is killed, a competitive smother crop is grown to outcompete any surviving weeds, and then that crop is killed prior to planting native grasses. In your urban yard, an organic alternative might be to use solarization, tillage, or intensive mowing to kill existing vegetation.

Depending on the area to cover, one might consider buying seed or plugs. For plugs, assume that a native grass plant can be anywhere from one to three feet in diameter, so be sure to plan accordingly. Seeding can be a challenge given the seed is fluffy; try mixing the seed with play sand, cracked corn, or pelletized lime to make it easier to broadcast. Native grass seeding rates can vary, but plan to eventually get at least 1 seedling per square foot of allotted space.

Limiting weed competition is crucial in the establishment period, as has been seen in recent work from Virginia Tech. Introduced annual grasses, such as foxtails and crabgrass, can be hard to control in native stands. If using plugs, consider mulching around plants with straw.

When considering where to add native grasses to your landscaping, keep in mind that they’re difficult to move once established. The only non-chemical way to remove them is to mow them to the ground several times over the next few growing seasons.

Bring native grasses home

Grasses can withstand droughts and the occasional flood, so they’ll fit in almost anywhere. They’re just right for those tough areas in your area yard that don’t seem to yield anything. They’re not a nutrient hog nor do they require a lot of human attention. Most historic grasslands worked on long-term nutrient cycles, so traditional soil fertility is not as pressing a management concern.

If you have a full-sun area, perhaps next to a road, consider sideoats grama (Bouteloua curtipendula). They will thrive in your rain garden and help prevent water runoff. For shady areas, grass cousins such as sedges would be a wise choice. Consider Pennsylvania sedge (Carex pensylvanica Lam.) and Eastern star sedge (Carex radiata).

Aesthetic considerations

A huge benefit of native grasses is their aesthetic beauty, and there are many species to consider. They come in various shapes, forms, colors, and produce seedpods that turn golden brown in the fall. Grasses can enhance almost any section of your landscaping.

Practically speaking, they make a lovely hedge or windbreak, whether you plant a long strip of the same species or create an interesting line of different heights and colors by using different species. Little bluestem is short and turns bright orange in the fall. Switchgrass grows tall and round and turns maroon in the fall. River oats provide winter interest with their silvery seedpods bending over a new-fallen snow.

Little bluestem (Schizachyrium) Photo Lady Bird Johnson Wildflower Center

Consider native grasses for your urban landscape

My yard isn’t completely devoid of native grasses. I remember spotting a Cooper’s Hawk in a stand of switch grass, watching a feeder for songbirds. Another spring I found an active bird nest in the same stand. With that kind of encouragement, I want more.

I have a slope full of wildflowers that floods several times a year but drains quickly. It’s perfect for rabbits but it’s rather wild and ugly. After struggling with this area for too many years, I believe native grasses will be the cure. I plan to clear and mulch large areas and then plant plugs of prairie dropseed (Sporobolus heterolepis), little bluestem (Schizachyrium), switchgrass (Panicum virgatum L.), and Eastern bottlebrush (Elymus hystrix L.). I look forward to hearing the wind blow through them and seeing them bent under snow.

Native grasses will improve the soil, create habitat for insects and in general, contribute to the health of your local ecosystem. When you consider that 70 percent of wildlife habitat in the United States is in private ownership, it’s clear that property owners have a responsibility to work toward restoration and native grasses should be a part of any plan.