Researchers said the potential herbicide -- dried distillers grains with solubles, or DDGS -- is a byproduct of converting corn to fuel ethanol.

DDGS is typically used as livestock feed but U.S. Department of Agriculture researchers Rick Boydston, Harold Collins and Steve Vaughn undertook a study to evaluate the use of DDGS as a weed deterrent on potted ornamentals.

They applied DDGS two ways: to the soil surface and mixed into the potting media of transplanted ornamentals.

Applied to the soil surface after transplanting, the researchers found DDGS caused no injury to plants and reduced the amount of common chickweed and annual bluegrass. Weed control was not perfect, Boydston said, but could reduce hand-weeding.

When mixed into the potting media, however, DDDS was toxic to transplanted rose, coreopsis and phlox plants.

The scientists noted additional research is needed to identify and confirm the safety of using DDGS on other ornamentals and its effectiveness of controlling other types of weeds.

The study results appeared in the February issue of HortScience.