Miller, James H.; Manning, Steven T.; Enloe, Stephen F. 2010. A management guide for invasive plants in southern forests. Gen. Tech. Rep. SRS–131. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 120 p.
Matt Nespeca, Executive Director of the Conservation Land Company in Charleston, SC, notes that, in the restoration of native grasses, herbicides can increase survival and growth of desirable native grasses and forbs, while reducing cover of invasive plants. It is important to know what plants a herbicide can control on a site, but it is even more important to understand what plants a herbicide will not control. On a restoration site, the idea of herbicide application selectivity (or the susceptibility or tolerance of a plant to a herbicide application) can be attained through herbicide spectrum, herbicide placement, or herbicide timing. Over the past several years, these methods have been used on native grass restoration projects throughout South Carolina, including Mepkin Abbey, McAlhaney Preserve, and Rock Hill Black Jack Heritage Preserve.
In some native grass restoration projects, a manager can rely on herbicide spectrum to provide selectivity. When bahiagrass is outcompeting an established stand of native big bluestem (Andropogon gerardii Vitman) and little bluestem [Schizachyrium scoparium (Michx.) Nash], a manager can use a broadcast herbicide treatment of Escort XP Herbicide (metsulfuron) to reduce the bahiagrass competition and release the native grasses. If the same established stand of big bluestem and little bluestem is infested by Johnsongrass, Plateau Herbicide (imazapic) provides selective control of Johnsongrass but is safe for the native grasses. A more obvious method of utilizing a herbicide spectrum in native grass restoration is with broadleaf-specific products, such as Garlon 4 Ultra (triclopyr), which control broadleaf species while releasing grasses.
Herbicide placement, as it relates to native grass restoration, can be accomplished through directed foliar applications to undesirable plants while avoiding contact with desirable plants. For example, Roundup Pro (glyphosate) will control many grasses during the growing season, but a skilled applicator can still treat patches of Bermudagrass in a restoration area while avoiding contact with desirable nearby grasses.
Herbicide timing can be effective in controlling cool-season grasses with nonselective herbicides, such as Roundup Pro when warm-season grasses are in dormancy. Herbicide timing is also effective for midwinter applications when nonnative evergreen shrubs such as Chinese privet are invading highly diverse grassland habitats where safety for existing forbs and grasses is essential.
