Corn meal for black spot and powdery mildew

Des Moines, south of, WA(Zone 8b)

I was reading a health column in the Seattle Times about a man who used cornmeal to help his toenail fungus and the doctor replied that he had heard from gardeners who used cornmeal on their roses to control black spot and powdery mildew because apparently cornmeal has some fungicidal properties.

Has anyone heard of this or tried it? On their roses, I mean.

Dublin, CA(Zone 9a)

I've heard of people using baking soda to control black spot, etc, and I've heard of corn gluten (not the same thing as cornmeal) as a preemergent herbicide, but never heard of cornmeal as an anitfungal.

Raleigh, NC

I've used it, and it seems to work, though not all the times. I rotate through a number of organic control methods, and sometimes there is no rhyme or reason why one works one season, but not the next. Check out the website (I hope I remembered it correctly...)

Marietta, GA(Zone 7b)

Happy birthday Mesmerel! :)


Fort Worth, TX(Zone 8a)

I sprinkle cornmeal on the ground under my rose and crepe myrtle to help with powdery mildew. I also steep about 1 cup of cornmeal in a gal. of water, then use the "cornmeal tea" to spray on my crepe myrtle to get rid of powdery mildew. Haven't tried it on my rose bush, tho.

The cornmeal works on the toe fungus, but it's a slow acting cure.


Adrian, MO(Zone 6a)

then why do farmers use a fungicide on corn?
perhaps the fungus has a preference for the corn over toenails or rose leaves. ???

Raleigh, NC

Funny question Len123!!!! I suspect its because the fungus on corn is on the PLANT, not the ear of CORN. Just a guess.....but you made me laugh, which is great!

Adrian, MO(Zone 6a)

I think your right yotedog.

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