Mildew
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What's the best treatment for mildew and just how toxic to animals (us) are commercial fungicides?
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(post #14715, reply #1 of 31)
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Best treatment I've found for Powdery Mildew is a 50/50 mix of fat free (formerly skim) Milk and water. On the lilacs and roses, with smooth leaf surfaces it seems to knock it down right away while on hairy leaf surfaces such as on monarda it takes more than one application but the first cuts it back by half and apparently stimulates new growth since mine are growing and blossoming again.
(post #14715, reply #2 of 31)
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Glad to hear a good report about using milk for mildew, I had only just recently gotten wind of that new "discovery". I'm not so sure the new growth is due to the milk (nourishment through the leaves?) or is it just the normal response of basically healthy a plant recovering from stress?
(post #14715, reply #3 of 31)
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Well I can test this out on my phlox--they look just awful! I might give up on the white variety, but I just love the look of 'Franz Schubert.'
I would suspect that the milk is supposed to have anti-mildew properties. I have heard good things about baking soda sprays to combat fungal diseases such as black spot. I'm trying that this year. I don't know how well it would work for mildew.
I have seen copper soap sprays advertised--and even tried them a couple of times--but they're just too expensive to use on a lot of plants.
(post #14715, reply #4 of 31)
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Bill, were you wondering about mildew on something other than plants?
(post #14715, reply #5 of 31)
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I recently was talking to some other folks about fungicides and said that I wasn't particularly worried about fungicides (vs insecticides). I was told that many commercial fungicides were toxic to humans since "fungi share many similarities to humans biochemically" (or something very much like that). I know that some fungi produce proteins found in animals but not green plants, which is why mushrooms are an important addition to a vegetarians diet, but I was not aware that fungicides would be of particular harm to animals. I was hoping for other opinions that could confirm or deny this.
(post #14715, reply #6 of 31)
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Well, if Elizabeth can prove that milk does control or eliminate mildew on her phlox then we have something that is both effective and not harmful to anything and useful for plants.Mildew on fabric or plastic is something else again. Anyone have a solution for that?
(post #14715, reply #7 of 31)
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Tilex. But as for commercial fungicides, except for the copper kinds, several of them have proved to be carcinogenic. I'm not too down on most commercial products, but I *won't* spray or recommend commercial fungal sprays for the garden. I'm going to give the milk thing a shot. I was all set to yank out my 'Franz Shcubert' due to its wicked mildew, but it put on such a spectacular show this year that I can't bring myself to get rid of it. Otherwise I usually get rid of and recommend getting rid of anything that gets mildew since that's the easiest (and till now, safest) way to deal with it. I hope the milk thing works, but even if it doesn't, I doubt I'll get rid of my 'F.S.'
(post #14715, reply #8 of 31)
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I'd guess that the milk spraying is like most other organic controls and needs to be started before the problem appears. My mildew is pretty intense by now, but I'll try spraying now and then try keeping it under control next year.
'F. S.'is really mildewy, but that color is so wonderful!
(post #14715, reply #9 of 31)
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Franz Schubert is the only phlox that survived my first real gardening year, i.e. planted in bricks. That is one tough plant. Mine is mildewing some but it is far enough back from the path that I can enjoy the blooms without having to look at the foliage too closely. One of my bee balms up by the house got mildew but it was pretty much done blooming, so I cut it back and the new foliage is fine, even threw a few more blooms. I would like more phlox though. Would powdered milk (reconstituted) work just as well? It would be a lot cheaper.
(post #14715, reply #10 of 31)
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I did some phlox spraying last night. We had bought two gallons of milk that tasted yucky (early spoiled), so I had milk to spare. Otherwise I would hate to buy gallons of milk just to spray on the phlox! (Really, I guess it's less expensive than commerical sprays.) One quarter of a gallon did a whole lot of phlox.
One lesson learned: keep the dogs inside while spraying milk!
(post #14715, reply #11 of 31)
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Powdered milk doesn't seem to have the same affect on PM. One of the studies I saw about controlling various pathogenic fungi on plants involved using raw milk to control tobacco mosaic virus, but since raw milk isn't easliy available to most of us, that treatment isn't to likely.
A cup of milk and a cup of water covers a lot of plant surface.
(post #14715, reply #12 of 31)
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Bill — I've been getting a heavy dose of mildew on my 2-year old lilac. By last September the leaves were absolutely covered with it. Then, this spring, I read somewhere that one cure is baking soda dissolved in water and sprayed on the plants. I tried it and — drum roll — it works!!
I suppose that it raises the pH to a point that mildew doesn't like. I didn't pay much attention to proportions, just about a half cup to about a gallon of water.
Try it. You've got nothing to lose.
(post #14715, reply #13 of 31)
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I have black powdery mildew on my herbs. What can I do to get rid of it. My hrebs are outside. I live in texas.
(post #14715, reply #14 of 31)
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That might be Downy mildew, a much worser fungal infection than powdery mildew. Remove and destroy all infected plant tissue. Since the milk spray has been shown to be effective on many fugal infections may help control it but most all sources I have say to use Bordeaux mixture.
(post #14715, reply #15 of 31)
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Worser! Someone else out there talks like me!!! I'm sorry, Kimm. I couldn't resist!
(post #14715, reply #16 of 31)
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I looked at my phlox this weekend, and I do think the milk spray helped. It looks like some (not all, but it was a Really bad case!) of the mildew has cleared up. I've been spraying my roses and tomatoes with baking soda (for black spot and septoria leaf spot, respectively), so perhaps I could use the same spray on them all. Baking soda is cheaper than milk...
I read somewhere that baking soda sprays don't work on hollyhocks (rust, I guess). Anyone know about that?
(post #14715, reply #17 of 31)
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I looked up some information on the milk's anti-mildew activity, and it may be related to the presence of lactoferrin, a protein with iron binding capacity. The binding of free iron suppresses the growth of bacteria and probably some fungi as well. The ability of lactoferrin to bind protein would be altered by dehydration and processing to powdered milk.
Kimm, do you know what it is about phlox, and other plants, that make them susceptible to mildew where other plants are not?
(post #14715, reply #18 of 31)
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Thanks Karen W. That explanation is better than anything I've been able to find other than some apparent relationship to pH.
I've also not been able to find any good explanation why some plants, Monarda, lilac, roses, phlox, etc. are susceptible to PM while others aren't. Just for the record, my phlox have not yet shown any inclination to support PM and this is the first year my Monarda have had it. Two climbing roses are fighting it this year for the first time also although that lilac has always had it, but a duaghter plant back in the woods never gets it, shadier location, less air movement (I'd suspect since its in amongst a lot of trees while Ma is fully exposed and gets sun all day). Difference in soil humus levels maybe?
(post #14715, reply #19 of 31)
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Hmmmmmm, seems that plants get PMS too (Powdery Mildew Syndrome) and not suprisingly, some worse than others. Is that why so many plants are named after women?
(post #14715, reply #20 of 31)
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'Cause we're purtier!
But you're right. Just about the only guy I can think of is 'David' and I ripped him up and threw him out this year because of all of his PMS problems. What I wonder is why a plant's PMS makes
i me
*******y.
(post #14715, reply #21 of 31)
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My Phlox "David" has never had any powdery mildew or the black spotty leaves that "Eva Cullem" seems to always have and a friend noticed this past week that "David" smells better than most of the others.
(post #14715, reply #22 of 31)
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I have always stuck with good old fashioned lavender phlox that has been passed down for generations in my family. I've yet (knock on wood) had any mildew on them. And this summer has been a good test with all the rain we've had.
(post #14715, reply #23 of 31)
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The thought occurs to me that one way plants are infected by mildew is by spores from another area of infection. This means that if the spores are carried by wind (I don't know, can't find any ref.) then that might be why infections of mildew seem so unpredictable.
(post #14715, reply #24 of 31)
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Mildew spores are indeed carried by the wind.
(post #14715, reply #25 of 31)
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I see that the posts on mildew treatment using milk are much stronger concentrate than that recommended in the Organic Gardening article, which was nine parts water to one part milk.
Also, as for Tilex on non-plant mildewed surfaces, I've used it, but some research into chlorine compounds is alarming. I want to move away from so much chemical use.
(post #14715, reply #26 of 31)
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Neem oil diluted in water is a great fungicide. Its available in Indian stores.
(post #14715, reply #27 of 31)
what is the Bordeaux mixture? I am fighting a losing battle with county park ground cover that I spent a fortune planting.
(post #14715, reply #28 of 31)
Bordeaux mix is a strong alkalia made from copper sulfate and hydrated lime. Ues is for Anthracnose, Bacterial Leaf Spot, Black Spot, Fire Blight, Peach Leaf Curl, Powdery Mildew, and the rusts, but because it is so strongly alkaline and there are many better things to use it is falling out of favor. Bordeaux mix would be a last resort product to use, if all else failed.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
(post #14715, reply #29 of 31)
do you have any recommendations that are "better" to fight downy mildew? Its indestructable!
(post #14715, reply #30 of 31)
Downy mildew is difficult to control, once established. Current theory is that it is soil borne so working at establishing a good, healthy soil with lots of organic matter may help since none of the organic gardeners I know, who have good, healthy soil, see this even thought it is often in a neighbors garden. Prevention is necessary since once the plant(s) are infected there is nothing to do but destroy them. if it is a real problem, and it is a disease of cool, moist weather, sprays of bordeaux mix or other copper based fungicides may be necessary.
There are several pathogens that cause this depending on the plant and apparently the pathogen that will cause downy mildew in grapes will not affect lettuce, for example, and that is probably why it is often difficult to get one single answer on control.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
Edited 12/16/2005 4:50 pm ET by KimmSr
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.