Q: Where can I buy bulk corn gluten meal? I want to do an organic care program on my 5000 square foot lawn.
A: Local nurseries sometimes carry small bags of the meal but you can also order it online. Expect to pay around $1.50 per pound for it, whether bought locally or online in bulk, due to shipping costs.
Tim Murphy, my weed control guru, says corn gluten meal, a by-product of the corn milling process, is thought to have pre-emergence activity on crabgrass and a few other annual weeds. Research in Iowa showed fifty percent control of crabgrass.
However, corn gluten meal has not performed as well in research conducted in several southern states. In both Arkansas and northern Florida, ten weeks after application, control was less than fifty percent or in some cases non-existent.
Most synthetic pre-emergence herbicides provide eighty to one hundred percent crabgrass control twenty weeks after application.