Corn is a type of grass, so use a broadleaf herbicide to control weeds around sweet corn without affecting it. For grass weeds, consult with your local extension office for suggestions. Weed killers are divided into three general types according to the plants it affects: grasses, broadleaf and broad spectrum. Broad spectrum kills all types of plants, so should not be used around corn plants.
About the Author
Hepzibah Flurge has been writing professionally since 2008. She is a horticulturist and her work appears on various websites and assorted gardening blogs. She holds a Bachelor of Science in horticulture.