Southeastern U.S. Sites
SOUTHEASTERN U.S. SITES include regions within the Carolinas, Southern Virginia, Georgia, and Florida. Sites in the southeast typically have sandy or clay-rich soils subject to drought. These characteristics necessitate a slightly different approach to native plant establishment.
Examples of SOUTHEASTERN SITES:
- Coastal plain soils
- Piedmont and sandy soils
- Mountain areas (refer to the Upland & Meadow Sites guide)
Eradicate existing vegetation by having a licensed spray technician apply an approved herbicide; i.e., glyphosate (Roundup®), or tilling the weeds into the soil. Good pre-seeding weed control may require spraying two applications of glyphosate (at least two weeks apart). Close mowing two weeks prior to spraying is recommended to stimulate weed growth. Glyphosate must be applied to vegetative growth in order to kill undesirable plants and their roots. The second application is needed only if the first application is insufficient. If excess dead plant material remains on the surface, burning or tilling may be necessary to achieve good seed-to-soil contact and sunlight penetration.
Sandy soils behave differently under cultivation than those containing clays. It is essential to plant into a firm seedbed, with a seed drill if possible, at a depth of 1/2” (Eastern Gamagrass should be planted at a depth of 1”). Truax drills can accommodate a variety of seeds and have been proven to be effective in the Southeast. Broadcasting seed is less effective due to the lack of seed-to-soil contact resulting from the sand content of the soil. Seedbeds should be firmed to the point where one does not sink past the sole of their shoe when traversing the prepared site. Soil amendments can be added, as necessary, to maintain proper levels of organic matter and to achieve a pH of at least 6.0.
Soils containing high clay levels can be as hard as concrete, often without topsoil, and pose a formidable challenge to successful cultivation. These soils are extremely low in organic matter, which allows the small clay particles to settle and become compacted after a rain event. This soil is often iron rich, leading to a distinctive red coloration. Organic matter must be added to this soil in order to prevent the clay from hardening after rain events, to the point where emergent seedlings will be unable to push through the soil surface. Organic matter, such as straw, compost, mulch, leaf litter, etc., must be added in order to increase soil organics to at least 1%. The organics must be worked into the top-most soil prior to planting using a tiller, harrow, disk, or similar implement. Cultivating the top 6”-8” of soil will aid in root development of emergent seedlings, and will allow some percolation of rain water that would otherwise run off the surface with little to no infiltration, likely carrying the seed away with it. These initial preparations are critical to the successful establishment of native plants in this challenging soil. Drilling seed at a depth of 1/4”-1/2” is the preferred method of planting, as soil compaction is minimized. Even with the addition of organic matter, this clay-rich soil will compact easily; therefore, operation of heavy equipment over the planted site should be avoided.
Habitat: Southeastern sites have a longer growing season; therefore, plants native or adapted to the region should be chosen. Planting from January through March is ideal whenever possible, as temperature is adequate and rain events are frequent. If irrigation is available, planting can continue into the later months of spring and early summer.
Fertility: With the exception of organic matter, natural fertility on these sites is generally adequate. Check your soil pH and add lime, if necessary, to achieve a pH of at least 6.0.
Seeding Method: Drilling seed is recommended; however, broadcasting is an alternative preceded with rolling or tracking.
After establishment, weed control and site maintenance practices in the Southeast are similar to those listed for northeastern sites. Use caution when applying herbicides over low-organic soils (clay or sand rich). The chemical breakdown of many herbicides is achieved via soil microbes, which generally feed off of organic material. With less organic material available in the soil, there will be a smaller population of microbes, which may result in longer periods of exposure to active ingredients within herbicides. Begin with lower than recommended concentrations of herbicides for weed control to avoid burning a valued crop when working in soils with low organic levels and high sand levels.