PLANT DISEASE CONTROL - For black spots on your roses, purple spots and yellow leaves on your photinia and Indian hawthorn, brown patch in your St. Augustine grass, damping off in newly planted seedlings or algae in your pond or water feature, you don’t have to use toxic chemicals like the synthetic fungicides such as Daconil or Bayleton or heavy metal products like copper sulfate. Whole ground cornmeal works better. Use it for root and soil borne fungal diseases at 10 - 20 lbs. per 1,000 square feet. Cornmeal works as a disease fighter in the soil by stimulating beneficial microorganisms that feed on pathogens such as brown patch (rhizoctonia) in St. Augustine, damping off disease (pythium, rhizoctonia, fusarium, and/or phytophthora) in seedlings and other fungal diseases in a wide range of plants. Use cornmeal at about 2 lbs. per 100 square feet around plants to help control any soil borne fungal diseases on both food and ornamental crops. One application may be all that is needed, but multiple applications are okay if necessary because cornmeal serves as a mild organic fertilizer and soil builder. Cornmeal needs moisture to activate. Rain won't hurt cornmeal's efficacy because, like all organic products, it is not water-soluble. Cornmeal tea can also be used for disease control. Soak 1 cup of cornmeal in 5 gallons of water for an hour, strain out the solids and spray the foliage of plants. It can also be used to drench the soil.
 

Cornmeal only works in an organic program. When toxic chemical products are used, the effect of the cornmeal will be lost. Additional information can be obtained from the following publications: Cornmeal – It’s Not Just Hog Feed Anymore, The Peanut Farmer, May 1996. Aquaculture Engineering 9 (1990) 175-186.