Proso millet is native to Eastern Asia and has since been introduced over centuries across various continents. Its range has expanded to include temperate and tropical regions in both hemispheres, encompassing parts of Africa, the Middle East, Europe, North and South America, as well as additional areas in Asia. Notably, proso millet is found as an introduced species in regions of the Mediterranean, the Americas, and Eastern Europe.

Proso millet originates from East Asia, specifically China and Eastern Siberia. It's considered a weed due to its aggressive growth, quick maturation, and habit of spreading quickly. These characteristics can choke out desirable plants in a garden, potentially causing damage. Also, proso millet can reproduce rapidly, for it produces a large number of seeds that have a considerable survival rate. This means they can easily and quickly infest a garden, making it difficult for other plants to compete for resources. The primary way it spreads is through its seeds. Because proso millet has a long seed viability, they can be transported by natural elements such as wind and water, or indirectly through animals. Thus, once proso millet finds a conducive environment, it sprouts and spreads its influence, becoming a stubborn weed that is hard to control.

The ideal season for the removal of proso millet is early spring, specifically during the initial stages of its growth. Removal is best carried out before the plant reaches its pre-flowering state, denying it the chance to produce and disperse seeds. Below are some methods of removal and control: