Clockwise from left: Cogongrass patch in Stanly County, off-center mid-vein of cogongrass blades, sharp rhizomes.
When invasive plants are introduced into an environment, they can cause major problems for native plants and wildlife. Some are worse than others, such as kudzu. But another non-native plant threatens the state and is thought to be much worse than kudzu and its car-engulfing capabilities. Cogongrass – considered by many experts to be one of the world’s worst weeds – has spread across the southeastern landscape and is at North Carolina’s doorstep.
Recently, a patch of cogongrass was found in Stanly County by Tom White and Jeremy Callicutt of the N.C. Forest Service. The infestation is being eliminated and surveys are being conducted nearby to determine if other patches are growing nearby. Last year, the first patch of cogongrass in the state was found and treated in Pender County.
Cogongrass can easily invade new areas if seeds or rhizomes (roots) are transported to another location. This can occur if equipment or commodities, such as hay, are contaminated. This sneaky grass is also difficult to spot with an untrained eye. In the case of cogongrass, the metaphorical snake in the grass is the grass!
There are several characteristics of cogongrass which put it on the “worst weeds” list. It can easily invade diverse areas and quickly displace native vegetation. Subsequently, ecosystem functions also change dramatically. For example, in a stand of longleaf pine, cogongrass causes more frequent and hotter wildfires compared to wildfires occurring in native longleaf pine habitats. Even though longleaf pine is adapted to fire, longleaf pine seedlings are unable to tolerate the frequent and hotter fires created by an established cogongrass stand.
Cogongrass can cause higher-intensity and more frequent fires than is suitable for native longleaf pine stands (Pender County).
The N.C. Forest Service and NCDA&CS Plant Industry Division are working together to prevent the establishment of cogongrass in the state. Personnel from both divisions are trained to identify the weed. When new spots are located, measures to eradicate are swiftly implemented.
It is helpful to have as many eyes in the field as possible. Cogongrass patches are typically circular. The grass blades have an off-center mid-vein and the rhizomes have sharp points and are scaly. A patch is easiest to spot when the grass is flowering, which occurs in early summer.
They say the grass is greener, but that is certainly not the case with cogongrass. The state hopes to remain cogongrass-free from this persistent and invasive weed. If you think you have spotted a cogongrass patch, call 1-800-206-9333 or send an email to newpest@ncagr.gov.