Folks, I had interesting results.

I brought in a potted chile pepper.

The leaves developed what looks like fly spec fungus.
I lost maybe 5% of the old leaves.

I place a 1/4 cup of cornmeal on the soil surface.

The spread of this fungus has stopped. The plant is developing new growth and new blossoms.

Thanks Nandina
Byron

EarthAngel, how do you mix this? What proportions do you use. I've been using alfalfa pellets for a couple of years with outstanding results and just started using the cornmeal this year for blackspot on my roses, so far it's working very well. It would be much easier to mix everything together and apply once. How often do you use this?

mrskjun,
I haven't been very scientific with the measurements but it doesn't seem to matter. I have 4 x 8 foot raised beds in a large garden and I put a 1 lb. coffee can of each of those four ingredients in each row and mix it in. My original plan was to use the formula when I felt the garden needed it, but after growing fall and spring gardens year around, I decided to use it every year, applying in the fall. I'm applying the formula in a different way this year (experimenting!) On vacation in NM, I found an organic formula which has all of these natural products plus a lot more and the price is comparable. Apparently, it's a Northern product because I can't get it any closer to Texas than NM. If you're interested, go to www.espoma.com and check it out. Good luck!

Around here the organic gardeners use corn meal every 3 months under roses.

Ask around at your feed store. Ask them what products they have containing corn meal. If you have a feed mill, shop there. I just found a product at my mill that I really like. It's called calf mix and has corn, cottonseed, milo, and oats all ground/mixed together. Another product called cattle mix has the same ingredients with salt added. I opted for the calf mix.

Would it be beneficial to make a mild cornmeal tea to water seedlings with? Would this help with dampening off?

If you are rooting in compost, it might help. If you are using a soiless mixture, you should just leave it alone.

What a great thread! I've been having fungal problems on my lantana - they're very xeric and the winter rains seem to be hard on them.

I'll be cutting them back soon, and shall try the cornmeal treatment to see if it works. Will report back.

This is very interesting, I will try the cornmeal on my 100 or so tomatoes and my wifes roses this year, as far as ants whole cloves spread around where you want to keep the ants out of works great, it seems to totaly disrupt their
scent(?) trails and they abandon their missions.

The following thread is discussing why cornmeal works:

http://forums.gardenweb.com/forums/load/organic/msg0315483014278.html?23

Here is a link that might be useful: why cornmeal works

Thanks for all the usefull information. Would it matter if the corn meal has lots of weavils? LOL Actually, I think they are dead, but maybe not. Also, I'm going to give the corn meal the supreme test....I have a New Dawn Rose that is coming out with first leaves with blackspot and a Climbing Peace that gets it so badly every year.I spray & spray with no results. I will let you know if this does the trick. I was about to dig up that darn Peace rose.

I was doing a search on cornmeal when I found the posting...after reading them all, I'm more convinced than ever....so count me in. I live in Southeast florida...black spot is a major problem...for roses and everything else. I'm off to the feed store..I'll let you know the results.

Hi all,

I found this thread last fall after fighting off black spot on several of my rose bushes. March of year I sprinkled about a handful of plain cornmeal under each of my rose bushes. One already had some black spot started. As of today, April 19, 2003, I am proud to say that none of my rose bushes have any sign of black spot. YEAH! ! !
I also used the dishwater trick on my ant piles. Yep! It works too. Had an ant pile I have been working on getting rid of for 3 years. GONE!!!
I am a believer.

This has been a very helpful thread. Just this morning I had to cut away allot of my two climbing roses due to black spot mold.

We have tried everything over the market that is suppose to work and nothing seems to do the trick. I am off to the store to get some cornmeal right now.

Thanks so much ya'll,
laura/Louisiana flower bug

Hi Louisianaflowerbug,

I live in zone 8 of Louisiana and am so happy to find out about the cornmeal too. I sprinkle once a month about two handsfull around each rose bush and don't care if it drops on the leaves some. My bushes are big and beautiful. Just a tad here and there of some black spot. Make sure you remove all leaves that have dropped off the bush or take off with clippers. Sterilize your clippers with 10% bleach and water solution between each cut on an infected plant. I am sure you will love the eventual outcome. I also put down a bit of epson salt on my plants. It encourages them to grow a strong root system. Good luck and if I can help you with any questions, feel free to ask.

Mary

I skimmed thru most of these, but think I only saw that cornmeal was suggested for fungus on plants and feet. It also works great for other skin problems. I heard about it on the radio. I put some in pantyhose and tie off the end and soak in the tub with it. If you squeeze it the "milk" comes out without the cornmeal itself. It has worked on my family for several skin irritations. I've also made a liquid and sprayed it directly on plant leaves. What a great, cheap discovery!

To Hippiechick,
Thanks for idea of making cornmeal tea by enclosing the cornmeal in panty hose. We are finding that one cup of cornmeal to one gallon of water and left to ferment slightly for 48 hours seems to be the most effective proportions. Perhaps it would be best for those planning to apply (spray) the cornmeal tea to also drip it through a coffee filter to prevent possible clogging of the sprayer nozzle...which is a pain in the neck to clean. To date I am finding that cornmeal spread on top of mulch (or soil) once a month and spraying cornmeal tea every two weeks on very fungus prone plants such as roses and tomatoes is very effective.

Glub..glub.. from my ARK on rain swollen creeks in the NC Piedmont..
Just found this forum. WOW! Am willing to buy the stock of an entire mill if necessary.

Boy am I glad I found this site. Corn Meal! I will go out and try it now. I never had blackspot before moving here. My neighbor in Virginia always had it. But I agree, Grits are made to be eaten, as long as the whites are done. Thanks guys! I will let you know what happens.
Mrst53

not for nothing but...i have a holly bush that had black spots on its leaves for 4 yrs in a row.

sprinkled , well poured corn meal under it twice in a months time. now a while has past and no blackspot.amazing!
dawn

Wish me luck! I just found this thread and am thrilled at the idea of something so simple and organic to treat blackspot. I recently put in several new rose bushes. The first batch has been fine until I brought the 2nd set home. I picked off all the effected leaves of the first one with black spot and sprayed all of the bushes. Now well into our wonderfully hot and humid summer all the bushes have blackspot. I hate the spray fungicide, which apparently doesn't seem to work to well on already established blackspot. Time to break out the cornmeal! Do you think if I dust the leaves it will help even more?

not happy with the rotting smell of cornmeal on my roses, when will that be gone? I dumped all my pots and am removing the clumps of garbage.

labrador,
I am mystified by your report of a "rotting cornmeal smell".
You are the first to report such an occurance. How much cornmeal are you applying to each plant? It only takes a handful sprinkled on the ground around each. Are you certain that you purchased pure cornmeal/ground corn and not the packaged self-rising cornmeal? Many times both package types look alike and you have to read the labels carefully. Personally, I have buried my yard and those of others with cornmeal (here in my hot, humid climate) conducting many experiments and have never had any odor from the cornmeal. Sorry, can't help you with an answer except to say that the odor, perhaps, might be coming from compost or some other soil additive you have used.

Do you need to reapply more often if you get a lot of rain, or will once a month still be ok?

WOW! This is my first time to lurk on this fourm, usually hang out at veggie & harvest fourms. I am a first year gardener with a desire to go organic and am learning so much. I just pulled out my 5 ft. tomato plants because of a fungas problem that I was determined not to put a chemical spray on. Wish I had read this first! New tomato plants were put out yesterday for fall, and as soon as daylight gets here I will be out with the cornmeal. Does anyone know if the cornmeal gluten with work as a preemergent for poison ivy?
Carrie

Just this morning my daughter was grumping about blackspot on her roses - talk about prayers being answered! Thanks - looks like we need to try this. & I'd been thinking of using alfalfa & maybe kelp on my gardens, (just moved into a 1900 'farmhouse' last fall, nice gardens, but tilth to build) so the cornmeal, molasses, kepl & alfalfa mix sounds great, too. THANKS, all of you.

I saw someone say that cornmeal will attract the worms and keep the ground fertile and airated, and it reminded me of when I was a kid :)

As a teenager I used to keep a rod and reel in the trunk of my car to go fishing any chance I got, so I bought a couple of "Worm Farms" from K-mart (a styrofoam cooler with the words "worm farm" printed on it and a bag of soil-less mix LOL!). I Just had to buy a carton of red wrigglers from the bait shop and drop them in, they were definately fruitful and multiplied... EXPONENTIALLY!

I used to feed them plain old cornmeal (I forget now how much or how often) but I always had a lot of happy worms hee hee. They dearly love the stuff, and the castings are pure gold for the garden. :)

Best Wishes
Amino-X

I tried the cornmeal (a small handfull at the base of each rose) about 6 weeks ago. 3 of 6 roses DEVELOPED blackspot after the application and the cornmeal became a hard, MOLDY mess! I used Goya brand yellow cornMEAL, NOT cornFLOUR or cornbread mix. Is there more to it than just "tossing" the cornmeal at the base of the plants?

An interesting aside: I decided to sprinkle a tad on a couple of emerging blooms that were being attacked my thrips and found no evidence of thrips the next day. They actually stayed away long enough for the buds to open with minimal thrip damage.

The roses I used the cornmeal on were: Mr. Lincoln, marmalade skies, angel face, french lace, dr. huey, and goldilocks. These are all in large (20" +) containers. Is the problem I'm having because they're in containers? Maybe it's the worms that help. I'll track some down and add them to the containers. Or, should I? SHEESH! I'm new to all this and don't quite know what to do! HELP! LOL

Thanks
Dee

Dee,
In general, we have concluded that cornmeal is not an effective plant fungicide for roses and tomatoes. Yet, some have reported success using it on both types of plants. In those cases these are gardeners who garden organically and use heavy amounts of compost and compost teas in their plantings. There have been some reports of success using cornmeal tea sprayed on tomatoes and roses, but these have been sketchy.

However, I do want to stress that positive reports of success are pouring in re using cornmeal for all lawn fungus problems and many other types of plant fungus problems. Just remember that when you scatter cornmeal on lawns or under affected plants it must be watered to activate it. This is very important.

Dee, your thrip report was very interesting. Okay, all you rose growers....try putting a pinch of cornmeal in each rose blossom when the thrips begin to attack. Let's see if Dee has made an important observation.

Interesting thread and I've learned more about this by reading tips on dirtdoctor.com as well. There are several "recipes" on the site. I'm curious if anyone has had results trying the cornmeal on powdery mildew on verbena. It seems the raised beds with mulch are promoting mildew and the verbena look awful despite their blooms. I'm so disappointed in the leaves and stems that I'm thinking of removing them and trying something else in the beds that likes moist soil. The Gazania in the beds are doing great. Thanks.

Deanne

I have 4 lilac bushes which tend to develop powdery mildew every year. This year it's worse than usual, and it appears that I may lose one of the bushes. There is fungus growing on the bark and the leaves are turning brown. Is there anything I can do to reverse the damage and prevent the fungus from spreading to the other lilac bushes? Will cornmeal help?

Amyhlr

Very recent evidence that scientists are actively investigation this fungus. The following is a quote from the introduction of a paper published in the December 2004 issue of Soil Biology and Biochemistry, volumn 36, pages 1955-1965.

Title: A duplex-PCR bioassay to detect a Trichoderma virens biocontrol isolate in non-sterile soil

Authors: Sarah L. Dodds, Robert A. Hill, Alison Stewarta

Authors affiliation: 'The National Centre for Advanced Bio-Protection Technologies, Lincoln University, P.O. Box 84, Canterbury, New Zealand and the Horticulture and Food Research Institute of NZ Ltd, Private Bag 3123, Hamilton, New Zealand

"Introduction

The biological control capabilities of species belonging to the fungal genus Trichoderma have been well documented over the past few decades (Hjeljord and Tronsmo, 1998). In particular, isolates of Trichoderma virens (formally Gliocladium virens) have demonstrated good biocontrol activity against a wide range of ornamental and vegetable fungal pathogens (Mishra et al., 2000; Nemec et al., 1996; Howell, 1991; Lewis and Lumsden, 2001; Rabeendran et al., 1998; McLean and Stewart, 2000; Prasad et al., 1999; Krauss and Soberanis, 2002). In addition, T. virens has also been reported to be active against root-knot nematode (Meyer et al., 2001) and responsible for reduced emergence of weeds in the glasshouse (Hutchinson, 1999).
However, regardless of the numerous successes there are still relatively few commercial products available with T. virens as the active ingredient (e.g. SoilGard", Grace Biopesticides, Columbia, MD, USA). The main reason is the high variation in the level of disease control achieved with the agent. To address this issue researchers are now focussed on understanding the mode of action and the ecology of the biocontrol agents with a view to manipulating conditions to achieve more consistent disease control."

Also of interest relative to using cornmeal. In the abstract they state: "soil was amended with cornmeal, as a nutrient source, and a mix of antibiotics to favour Trichoderma growth."

Ok, so I've been thrilled to death reading ALLLLL the way through this post only to see that.....cornmeal DOESN'T work for blackspot??? Is that right, Nandina?

Everyone seemed so excited about it for the last two years and now kaplooey?

I'm reaaally bummed. :( My roses are a MESS and I absolutely won't use the chemicals because of wildlife, insects...not to mention that you can't even get near the roses to smell them with that junk on! Ick! :)

ademink, the following thread has a subthread that discusses blackspot and friendly fungi (including the one that cornmeal encourages):

http://forums2.gardenweb.com/forums/load/roses/msg1013193422635.html?37

Here is a link that might be useful: link for above

Thanks for your time, Henry! :)

I note that this thread is reaching its 100 message limit. As it ends I would like to add a few thoughts.
It has been a very interesting adventure of discovery as many of you have trialed cornmeal and cornmeal teas as a plant fungicide. Your e-mails to me have been very helpful as you report your successes and failures. Thank you, Henry, for your latest postings. I am delighted that cornmeal is now undergoing further research. Although I have contacted a number of institutions begging them to undertake more research on the subject, the answer has always been the same...not interested if it cannot be patented and turned into a money making project.

Here's what I know to date on the subject of cornmeal as a plant fungicide:

1. The average gardener reports that cornmeal does not control blackspot on roses or tomato fungus problems. My trials have yielded the same observation.

2. Cornmeal, when dampened allows Trichoderma fungus, which is the 'good one', to feed on the mycelium and sclerotia of the bad, unwanted fungi Sclerotina minor, Sclerotina rolfsii and Rhizoctina sp. and kills or controls them. So....if fighting a fungus or mildew problem, try cornmeal. If it doesn't work....it doesn't. Simply put, the fungus which is your problem is not in the family of fungi listed above.

3. The posters over on the Lawn Forum have really been giving cornmeal a workout. Many are now buying it in bulk from feed stores and even local bakeries will order it in for you if asked. They are spreading it on lawns because cornmeal contains 10% slow release, non burning nitrogen. Also, it does control lawn Brown Patch when spread on and around the infected spots and watered in once a week for three weeks. To date no reports of injury to lawn grasses using cornmeal. Others are working cormeal into garden beds and appear pleased with the results. Just a reminder, use food grade, cooking type cornmeal (as from a bakery or grocery store) on vegetable gardens, please. Those who have trialed using cornmeal to control lawn rust and red thread infections do not report that it is a successful cure to date. Several other organic ideas are being trialed on those two problems.

And so, we have found that cornmeal is an effective plant fungicide for a number of situations. We still do not have all the answers, but we have some. It is an inexpensive, organic method which every gardener should try when dealing with a fungus problem. Success using it depends upon the type of fungus infection causing the problem.
We are making progress!

4.

For those with a scientific background: a recent (2004) scientific review of Trichoderma beneficial behavior by a very impressive group of scientists is given at:

http://www.weizmann.ac.il/Biological_Chemistry/scientist/Chet/NR.pdf

You may be interested in looking at the list of who supported this research on page 56. It appears that a number of scientific groups are taking biocontrol by trichoderma seriously.

Of course you can probably spread all of the cornmeal in the world on a waste chemical dump (i.e. a garden that has been routinely sprayed with chemical fungicides) and short term you will only see a fertilizing effect as the cornmeal is only the food for the trichoderma fungi - which probably will not be present if residual chemical fungicides are present.

Here is a link that might be useful: link for abive

New research supports the trichoderma model.

Http://www.publish.csiro.au/nid/39/paper/AP03070.htm

Title: Monitoring the survival and spread of the biocontrol fungus Trichoderma atroviride (C65) on kiwifruit using a molecular marker

Authors: S. L. Dodd, R. A. Hill and A. Stewart

Published in: Australasian Plant Pathology, volumn 33, pages 189 - 196, (2004).

Abstract: "An isolate-specific restriction fragment length polymorphism (RFLP) marker previously found for the Trichoderma atroviride (formerly T. harzianum) isolate C65, an isolate with biological control activity against the kiwifruit stem-end rot pathogen Botrytis cinerea, was modified into a dot blot assay to facilitate the screening of large numbers of leaf and flower/fruit samples for the presence of C65. To increase sensitivity, the dot-blot assay was used in conjunction with a Trichoderma semi-selective medium. This modified diagnostic assay was used to track the survival and spread of C65 on kiwifruit leaves in the shadehouse and flowers/fruit in the orchard over two consecutive growing seasons in the Canterbury region of New Zealand. Results showed that isolate C65 could survive on both leaves and flowers/fruit over an entire growing season. The fungus, applied once in early summer (late November/early December) to coincide with bud burst, was detected on both leaves and fruit through to harvest in late summer (March). In addition to its ability to survive, isolate C65 was shown to spread to uninoculated leaves and fruit on the same plant and plants at least 3 m away. It is postulated that the high population of thrips present in the orchard at flowering was responsible for spread of the fungus within the orchard and that resident insects or wind currents could be responsible for spread in the shadehouse. The ability of C65 to survive and spread in the phylloplane and fructoplane of kiwifruit vines over an entire growing season makes it an ideal candidate biological control agent for reducing B. cinerea inoculum in the orchard at harvest and, consequently, post-harvest fruit rot."

Here is a link that might be useful: link for above

Well I have certainly enjoyed reading this thread all the way through and now I will put cornmeal on my calendar for March to scatter under all my azaleas and rhodos. Have had terrible problems the last 2 years with all the rain. We're getting various fungal infections and black spot type production on them. I just finished tonight putting down Hollytone under all the azalea, rhodo and pieris, which is an Espoma product somebody else mentioned. This is my first year doing this but I've heard fantastic results from other people.

I do have a question which may not get answered on this thread - lets see. Due to an illness, my DH couldn't blow all the leaves this fall from our 2 acres back here in the woods. I can't even start the darn blower so I finally started just mowed the lawn every few days with a composting mower and left the chopped leaves in place. I also put down an application of pelletized lime. Our soil is very very hard compacted clay over granite. We have a continual problem with acid pH, mushrooms, moss, etc. I was going to have the soil aerated again and then spread a dusting of mushroom compost. Would cornmeal do just as good a job at a fraction of the cost?

Title: Biological control of black spot of rose caused by Dipocarpon rosae .

Authors: Prasad, R. D.; Rangeshwaran, R.; Sunanda, C. R.; Vinita, J.

Authors affiliation: Project Directorate of Biological Control, Post Bag No. 2491, H.A. Farm Post, Bellary Road, Hebbal, Bangalore 560 024, India.

Published in: Annals of Plant Protection Sciences,volumn 10, pages 256-259, (2002).

Abstract: "Fungal biological control agents (Trichoderma harzianum , T. viride and Chaetomium globosum ) were used either alone or in combination with fungicides (chlorothalonil and mancozeb) to manage black spot of rose caused by D. rosae under greenhouse conditions. Black spot incidence in biological control agent and/or fungicide treatments was significantly low (disease ratings from 0.33 to 3.33) compared to the control at all observation dates. After 100 days of spraying, defoliation was lowest with chiorothalonil, Trichoderma harzianum +chlorothalonil, C. globosum +chlorothalonil and T. harzianum +mancozeb treatments. The highest mean vigour index was recorded in T. harzianum treatment. The highest flower production was recorded in C. globosum +chlorothalonil treatment (4.33) followed by T. harzianum alone and T. harzianum +chlorothalonil treatment (4.00)."

I had blackspot on my August Beauty gardenia, read the postings here and sprinkled uncooked instant grits under the bush. Ha ha, I didn't have any plain old cornmeal and was too lazy to go to the store. I pulled off the infected leaves also.
This was one month ago. Haven't seen a spot since.

I know this is an old thread. I have a 5 lb bag of masa harina, I was going to throw out. Would it be ok to use instead of reg. cornmeal. It says in the ingredient panel corn lye, and water. I know the lye is used to de-hul the corn and then rinsed off well. I'm scared , I might kill my plants.

I haven't seen any improvement after using the corn meal around my roses. I noticed on the corn meal box that it says "enriched and degerminated". Is there another kind of corn meal that I should be using?

Hi,
VERY interesting forum (I just joined). I live in Kenya (africa) and I would like to use the corn meal method for fungus. We, in Africa grow maize (and maize meal). Is this what you are calling corn meal?

Kenyacowgirl, welcome! Yes, maize meal is another name for corn meal. Although it does not solve all plant fungus problems it still is worth trying, on the off chance it might. There are a number of fungi families, some of which maize meal will control. Hope it works for you.

What kind of cornmeal do I use? Do you use the plain cornmeal at the grocery store or the self rising?

Hrrannie, use regular cornmeal from the grocery store. In some parts of the country feed stores carry cornmeal in 50# bags inexpensively. You might want to check and see if yours does.

Ye gads!
I wonder why some of this stuff stays around.
There is a difference between corn gluten (not gluton) meal and cornmeal; the corn gluten meal is the (somewhat effective) proteins plus other materials milled off whole cornmeal, and which actually contains no gluten. It does work as a pre-emergent herbicide in some situations. Do your research to find how, and rather than doing it the lazy way on most organic gardening forums, read abstracts from university research papers and university horticulture forums (I suggest the WSU Extension forum from Puyallup, WA). You can also find whole grain cornmeal at some better grocery stores. It has the corn gluten intact, if you want it.
Corn meal is good food for snails, some rodents and insects.
Cornmeal and corn gluten meal are both good substrates for growing some kinds of fungi for research purposes. Just get some moist, perhaps on a pot of wet soil, leave in the shade, keep it moist and/or covered, and see what grows.
As a pre-emergent herbicide, cornmeal is not so effective, and under just the right conditions (look up elsewhere how to do it right) corn gluten meal is a good pre-emergent herbicide, even if a bit $$.
There is not much guarantee that your corn gluten meal would be OMRI certifiable, for most of it is made from GMO field corn. After all, since most of it goes into animal feed, and the feed producers care mostly about the bottom line, why ask for non-GMO corn sources?
net-net: do better research in finding the papers and abstracts, and read critically. Then you won't be panicking about where to find cornmeal or corn gluten meal for your garden. As for tomato spot disease, just try to find supporting studies on cornmeal for preventing that...you'll likely only find anecdotal reports from some home gardeners who have been successful one season, and attribute that success to the cornmeal, but have no control against which to compare.

Hi y'all! I've been hunting all over the Internet for some hope to deal with blackspot on roses--and you guys have finally given me some! We tore out out our front yard completely (clay, broken glass, and weeds), and put in brick paths, a pergola, and rose beds. I have 45 roses, of which about two thirds are Knockouts & the rest are own-root heritage roses. All of them are SUPPOSED to be resistant to blackspot. Ha! They're planted 3-4 feet apart, they get a good amount of sun, but there are a number of oak trees that provide partial shade, and last year they were DECIMATED by blackspot. By June, I didn't have a single flower for the rest of the season. So sad!

This spring I started spraying weekly with a mixture of water, kefir (better than milk, I'd hoped?) & neem oil (but not the 100% stuff, apparently). No go. The blackspot is back. I'm going to try baking soda & 100% neem (any reason NOT to try them together?) and run out and get CORNMEAL ASAP!

3 years ago I put cornmeal around my crape myrtles to try to control the black mold on the leaves. This took care of it and I haven't had any more problems with it. Another thing I did after reading this hint on the forums was using flour to control leaf rollers on my cannas it too worked great. Used it 3 years ago and haven't had to use it again. Great, easy and cheap solutions.