Tiger lily, The cornmeal does work. Several years ago the Expermintial Station at Texas A & M University had a field of peanuts with some kind of fungus that they was not able to control with many of the fungicides used. They finally dusted with cornmeal. It stopped it within 24 hours.

Three years ago, my wife came in the house and said the okra which was coming up had dampening off disease. I got the cornmeal and dusted them. Next morning it had stopped, and had no more trouble. I have been using it ever since.

Now the theory is that it feeds beneficial bacteria which multiplies rapidly and destroys the fungus.

Molases will also work. Mix about one-half cup in hot water in order to get it to mix good, then add enough cold water to make a gallon. Spray with this. It makes an excellent foliar spray as well.

Another one I use is cornmeal, wheat bran and dried molasses. Use this as you use the corn meal. If it is a soil fungus, then sprinkling it on top of the soil will do the trick. As this breaks down it provides nutrients which is better than any chemical fertilizers.

I used it last year on my roses and it really worked

Since someone mentioned "dusting" it on, could you please clarify if you mean CORNMEAL (for making cornbread), or CORNSTARCH (for making sauces)?

Thanks, I had never heard of this.

Cornmeal.

Although I think there was a discussion in Nandina's thread that cornstarch would work as well.

I've been following the cornmeal threads and still am not clear.

By dusting, do you mean taking a handful of cornmeal and sprinkling it on your plants's foliage?

I am planning on "mulching" with cornmeal this year. Does the cornmeal have to be on top of the surface of the soil to work? Or can it be underneath the bark mulch?

When mulching, how much do I use?

To answer the above questions:

1. Yes, plain old cooking cornmeal from the grocery store is what you should use. I have not experimented with using corn starch as a fungicide so cannot comment on that. Cornmeal is easier to apply.

2. Cornmeal should be sprinkled around each plant on top of the mulch and then hose it down lightly. No need to drown it. If some of the cornmeal sticks to the plants, as it will on tomatoes which have 'hairy' stems, don't worry about it. The plant will not be harmed.

3. Heavy applications or mulching with cornmeal really is not necessary. Just sprinkle handfuls around the plants. Fast and easy job.

4. Just a reminder. Any plant you grow such as tomatoes, roses, etc. that exhibits fungus/mildew problems every year can be treated with cornmeal. BUT, you must start the cornmeal treatment as the weather warms up in early spring when the first growth appears. Or, when you plant an annual plant such as tomatoes. Repeat the cornmeal applications once a month.

5. We do not have all the answers on using cornmeal as a fungicide. That is why I am hoping that people will report their successes and failures as the growing season progresses.

Thanks, Nandina. Now I get it.

Can't wait to try it.

So far not much problems with blackspot, but we've had dry summers lately and I buy resistant (as much as can be expected) varieties. Am going to use the cornmeal anyways.

Definitely will try on tomatoes. They always succumb to some kind of blight sooner or later, usually later but would love to end the year with blight-free plants.