Controlling weeds with corn gluten

Listen to this radio story (MP3 download) or read below.

Radio interview source: Dr. Nick Christians, horticulture/turf specialist, Iowa State University

I've never used fertilizer on my yard, because I try to keep our chemical use to a minimum. I'm always looking for more natural alternatives, so I thought it was interesting when I heard that Iowa State University Turf Specialist Nick Christians, pictured here, discovered that spreading corn gluten meal on grass prevented weeds from growing.

"It works as a natural pre-emergence herbicide. There are some low-molecular-weight proteins in it that inhibit the formation of roots at the time of seed germination," Christians says. "And it's only the seedling root, it does not have the same effect on the roots of mature plants."

While this natural bi-product of corn won't kill off the dandelions already in bloom, it does prevent germination of a variety of major broadleaf and grassy weed seeds. Christians recommends applying 20 pounds of product per 1,000 square feet of space.

Timing is everything for this to work. Put it down two to three weeks before weed germination, and then again later in the season about mid-August. Moisture is necessary to activate the material, but extended wet periods might reduce its effectiveness.