Carolina geranium is native to North America and invasive in China. It is sold commercially and is beneficial to pollinators, but is otherwise considered a weed throughout North America. It colonizes disturbed areas, including fields, lawns, and roadsides, where it can compete with native or desired species, although environmental impacts are typically considered low. In areas where it is invasive or becomes weedy, there are several options for control. Hand-pulling is a viable option due to its shallow taproot. A mulch later of at least 8 cm can prevent germination. Herbicides containing dithiopyr or isoxaben can be used to prevent germination, while herbicides containing glyphosate can be used to kill the weeds after establishment.

Once the weeds start to flower and fructify, it will be difficult to control them effectively. In fact, the best time to remove weeds is before flowering and fructification because the seeds will spread rapidly after that. So, it is necessary to remove weeds more often and to take precautions in advance next year. Mulching: During the seed stage, covering with sawdust, straws or black mulches to effectively inhibit seed germination and the growth of the seedling. Generally, this method is used in winter or spring to inhibit the germination of weed in the soil. If the weeds have already flowered and fructified, this method can be used to isolate the seeds and the soil to prevent the seeds from falling into the soil. Pulling out: Before the weeds fructify, wear gloves or use tools to pull them out. If it is difficult to pull out weed due to dry soil, adding water to the soil helps to make it easy to remove the roots thoroughly. After pulling out the weed, deep tillage can be adopted to remove the residual roots. This method is especially effective for weeds that are in the seedling stage or low growing size. Pruning: Pruning weeds before they fructify can effectively control the propagation of weeds, especially for annual weeds. Frequent pruning can inhibit the growth and fructification of weeds and effectively them in the same year. Plowing: Before cultivation, plow the soil, collect and discard the roots of perennial weeds, then expose them to the sun or bury them deeply. It can also be used for retting organic fertilizer and composting. Chemical control: Using appropriate herbicides can effectively remove the weed from the area. Note: When removing weeds, it is necessary to wear gloves to avoid direct contact with the weeds, especially for the ones that are poisonous, thorny and allergenic. When removing weeds at the flowering stage, special masks should be worn to prevent allergic reactions caused by the inhalation of pollen.