Above: Nonnative, invasive Lespedeza species, bicolor lespedeza (Lespedeza bicolor), left, and sericea lespedeza (Lespedeza cuneata).
The genus Lespedeza contains many native plant species distributed throughout the Southeastern U.S.
These legumes all have trifoliate leaves (each leaf has three leaflets) and some are important for wildlife as they provide seeds, cover, and harbor insects that many birds consume.
However, there are also a few nonnative invasive Lespedeza species that are of concern to the quail manager. The most notable are sericea lespedeza (Lespedeza cuneata) and bicolor lespedeza (Lespedeza bicolor) which is also known as shrub lespedeza.
Sericea is one of the most problematic invasive plants in the Mid-South. This aggressive perennial can form dense monocultures that inhibit more desirable plants. It thrives with late winter/spring burning. While it produces abundant seed, the hard seed often passes through the gut of birds completely undigested providing no nutritional value. It occurs throughout the Coastal Plains as well, although it tends to not be as aggressive in the sandy acidic soils found in these regions.
Note: there is a native look-alike called slender lespedeza (Lespedeza virginica) which can most reliably be distinguished by the complex branching leaf venation as opposed to the linear leaf venation of sericea when held up to light.
There are several herbicides that can control sericea, but triclopyr and metsulfuron-methyl (MSM) are the preferred options. Triclopyr (e.g. Garlon or Remedy) should be sprayed at a rate of 2-3% when the plant is actively growing. As this herbicide will kill or injure many other broadleaved plants, spot spraying is recommended to minimize collateral damage. For large areas that are heavily invaded, consider MSM (e.g. Escort or Manor) at a rate of 1 gram per gallon.
MSM should only be sprayed once sericea is actively blooming which may occur as late as September in most areas as it is not very effective earlier in the season. While a more limited control window exists, MSM is tolerated by many other plants so collateral damage can be minimized.
However, oaks DO NOT tolerate this soil active herbicide so avoid spaying under the drip line of desirable oaks. Use a non-ionic surfactant with either herbicide (0.5-1%). Finally, a late summer fire (August or September) can help suppress sericea in areas where this season of burn fits other management goals.
Bicolor lespedeza is a shrubby perennial plant that also forms monocultures suppressing other desirable plants. In the past it was widely planted for bobwhite before managers realized how aggressive it could be.
Further problematic is that it can be so dense and tall that it is difficult to quail hunt and shoot through. While it is aggressive across much of the Southeast, it tends to not be as aggressive on sandy poor soils as compared to more productive sites. Herbicide is the primary control method with triclopyr generally being the preferred option at a rate of 2-3% with a 0.5-1% non-ionic surfactant. Due to the height of this plant, it is sometimes helpful to mow first and allow regrowth to at least thigh high before spraying.
Rarely can either of these invasive legumes be eradicated from a property once they are well established as the seeds persist for years in the soil. However, both can be managed to keep them at tolerable levels to meet wildlife objectives. If they are not already present on a site, be vigilant to their establishment and quickly act to control before they cast seed. AI assisted plant apps can be helpful to identify these plants until you create your own internal search image.
