If it were that easy to prevent black spot, everyone would do that.

But it isn't.

I think milk might have some benefits! I still use it in my fish emulsion foliar feeding because I like the results. I know it doesn't clear up bad cases of blackspot, at least, but that's not to say that it does no good. My roses like it as a food, anyway ;) I never have stopped using it.

I'm single, too, and it's hard to drink the milk in time :D

A well known garden magazine - can't remember which one- big and nice heavy glossy pages- was suggesting buttermilk for mildew supression a while back. I know buttermilk and water can make a good climate for mosses if you are trying to grow those. A mail order moss farm has you put moss in a blender with buttermilk and water and then paint it all over with a paintbrush if you want to get moss going on rocks, bricks, etc.

I forgot to add that the milk spray also included a small piece of garlic in the spray bottle. I sprayed the milk/garlic spray on my Old Garden Roses that I have in pots and the roses started putting on new growth.

It's well established that milk solution (10-20% any kind of milk) is an effective powdery mildew control. It might help a little with blackspot, but I wouldn't expect control.

Powdery mildew lives on the surface of leaves and canes where it is vulnerable to many kinds of control. You can even drop pruned PM-infected plant material on the ground beneath the rose bush to return nutrients to the soil because PM dies when it is not on living plant tissue.

Blackspot is much harder to deal with, unfortunately, in part because none of the things I said about powdery mildew are true about blackspot.

I wish it were otherwise.

Rosefolly

Haha -- had to laugh. Milk spray does not work on powdery mildew here in powdery mildew heaven -- coastal marine zone Southern California.

BUT, I have been having some good results with a dilute spray of hydrogen peroxide. I'll have to wait until we get our June gloom weather back this winter to give further results, but so far, all systems go on that one.

(I have been using about a 10% strength of the grocery store (el-cheapo) version of Hydrogen Peroxide -- between 1 cup and 1 pint in a 4 gal sprayer, depending on my mood that day.)

Milk spray does work for BS The horticulture proffessor at U Minn likes to test out common garden remedies. He found that 1 part milk (any type) to 2 part water sprayed once a week really did have an effect comparable to the heavy chemical sprays. Powdery Mildew is supposed to be easier to deal with because spraying with just water is supposed to wash away the spores. I do not remember how often it should be done.

Interesting Kathy, I will look forward to hearing about your results next fog season.

One thing to remember, spraying something one day and having giant sprays of roses the next is more likely a function of not noticing them the first day than what we spray.

" He found that 1 part milk (any type) to 2 part water sprayed once a week really did have an effect comparable to the heavy chemical sprays."

You will have to show me the results of a control study before I would even start to believe that.

Here is the link to the study on th effectiveness of milk spray for black spot: http://jeffgillman.net/5.html

Here is the organic gardening author on the a video with Martha Stewart
http://www.marthastewart.com/251406/garden-remedies-1

Here is the organic gardening author on the a video with Martha Stewart
http://www.marthastewart.com/251406/garden-remedies-1

I do not consider Martha Stewart a scientific source; nor is the other source cited above (Jeff Gillman), at least not at the webpage linked to. In fact, all Gillman says is this very general statement:

When we tested milk against other home remedies it beat everything else easily. In fact, it was just about as good as the synthetic fungicide Chlorotalonil and the organic fungicide Bordeaux mix.

So what is that generality claiming? That milk works better than "other home remedies"--and if we read down the page, the specific home remedy mentioned is the Cornell baking soda mix which many of our forumers have tried out and found inadequate.

The Gillman source also generally observes that milk is as good as the synthetic fungicide Chlorotalonil. (Notice that no documentation is given for that claim, so we have no way of knowing how valid--or not--it is.) For those of you who don't keep up on Latinate names, that is basically the brand product called Daconil -- which most forumers here do NOT use because the Bayer Disease Control product works so much better.

Gillman does NOT compare milk to the truly effective BS control put out by Bayer--probably because his milk treatment cannot even begin to compete with the popular and widely used Bayer Disease Control, wouldn't you imagine?

For those who wish to see a truly more scientific study of Chlorotalonil, here is a source put out by the EPA. Note that it does not even refer to using it to control BS on roses--because its main and widespread use is agricultural crops like potatoes, and also on turf grass. And in paint.

So what it all adds up to is that milk has some good effects if you spray it weekly and after it rains or the rose got wet somehow.

However, in my opinion, if you want truly effective control of BS on your roses, you would be much better off with a product like Bayer Garden Disease Control for Roses, Flowers, and Shrubs--with which milk cannot even begin to compete.

Kate

Here is a link that might be useful: EPA on Chlorotalonil

This post was edited by dublinbay on Mon, Sep 16, 13 at 13:13

It should also be pointed put that the Gillman study linked to does not include any control data, so if the study doesn't compare milk application to a control group, it's meaningless. This is the kind of nonsense "research" that generates misinformation that gets propagated to become the "miracle cure" baloney-of-the-year that we can do without.

Case in point: you all remember the Miracid Blackspot Cure from twelve or so years ago?

Thanks for your opinions and information. This means more reading for me.

Thanks for your opinions and information. This means more reading for me.

Don't be disheartened, Thomas, just all part and parcel of gardening in general. We all rely on a mish-mash of this and that.....but more importantly, there will be things which work brilliantly for one person while being useless for you. Don't worry - you will probably end up with a few sterling performers, a few iffy types and a couple of needy wimps which need life-support. You will also learn the useful trick of selective viewing.

I DO actually remember the "Miracid Black spot Cure" that was being promoted on the internet -even on these forums - a while back.

One thing about these claims in general is that the "cures" are rarely promoted by a packager of the product. Packagers have to be very careful about what they say about the pesticide uses of their products. Besides requiring proof, such claims may also put their products into a completely different regulatory category. So you can bet that if a packager or a representative makes a specific pesticide claim, it is backed up with at least some reputable evidence.

On the other hand, private individuals can make whatever claims they want about using just about anything as a pesticide. And they pretty much do.

Thomas, thank you for providing more information.

Jeff Gillman was a PhD professor of horticulture at UMN, and even though he lost that job (or quit for some reason), he knows what he is doing, and I don't think he is a charlatan like the Dirt Doctor.

So I take his word that he ran a controlled study. I don't know why he hasn't published it, because the finding seems very important. Maybe the study was too small and informal to meet professional standards--in which case he doesn't really have a finding. But chlorothalonil (misspelled above) is in fact an effective blackspot fungicide, so if milk were equally effective, that would be wonderful.

One thing, he used a lot of milk, about a quart a week per 20 roses, and a richer mixture than I have seen used before. If I were still an organic gardener, I would try spraying this on half the roses for a few months, leave the others unsprayed, and see if there is a difference. Of course, the roses would smell like cheese.

So Thomas, if you try this, do try to provide some degree of control.

PS: the Miracid craze started here on the GWeb Roses Forum.

This post was edited by michaelg on Tue, Sep 17, 13 at 13:31

Question for those in the know:

Do you think when an idea like the Miracid (before my rose time) was around that people had an expectation of what the results where and then "found" them to be true (ignoring what did not fit in what they expected)? And with more and more people "finding" similar results and relying on previously reported anecdotal evidence that it made the results be reported as truth by people deeper in the rose industry?

Hope I asked that so it makes sense.

Sorry to be hijacking Thomas's thread.

The Miracid thing started in the summer. In the Midwest, Texas, and the inland South, it can get too hot, as well as too dry, for blackspot to spread. That's is probably why the "discoverer," who was in St. Louis, noticed an improvement. Then, as you say, people tend to see what they hope to see, or see things that confirm beliefs they already have. And yes, I suppose most people who tried Miracid for blackspot wanted it to work.That can be an issue in the observations made by scientists as well as laypeople. So when an experiment or study is replicated, sometimes the original findings don't show up, and then the original study is discredited. That's why formal science makes progress--it is able to correct errors.

I sent these questions to Jeff Gillman, now at Central Piedmont Community College:

Why did you choose a 1:2 solution of milk?

How many plants received the milk treatment? Were all plants in the study the same variety with the same sun/rain exposure?

Do you consider this to be a publishable result? How confident are you that you had a significant finding?

May I post your response on a gardening forum?

And he answered:

Hi Michael,

You may post my responses --

We used a 2:1 water to milk solution because we were trying garden myths and that's the recipe that we found -- Unfortunately I can't remember where. We tested 9 plants with the milk treatment. All roses were the same -- they were black spot susceptible -- I'm sorry, but I can't remember the cultivar. David Zlesak at UW River Falls would probably remember -- he ran the experiment with me. I'm rather confident that we had a significant finding, and though we did not publish these results, we did publish a similar experiment in Fungicide and Nematicide Tests. I can't remember whether David published these results in a rose book....he may have....you'd need to ask him.

Best Regards,

Jeff Gillman

Thanks everyone. This thread went far above my expectations. I appreciate all comments. Thanks for contacting the author.

I have noticed that milk solution works well on powdery mildew on my zinnias. Last year about this time I had to dig up and throw away my zinnias. This year I do not see any powdery mildew on my zinnias. (That is another thread. I was growing the zinnias fro seed in pots and they would not grow more that 2 or 3 inches tall until I put a teaspoon of undiluted regular Miracle-Grow on the top of the soil and let it sit there for a week. The next week I watered the zinnias with diluted Miracle-Grow with molasses water. Now I just water the zinnias with water, or molasses water. I don't like using Miracle-Grow but I felt I had to for the zinnias).

I have been testing (at separate times) milk and garlic solution spray; peroxide spray; and sodium bicarbonate spray for blackspot on roses. I must say I like the milk and garlic mixture best (When I use sodium bicarbonate, I am probably using too much). The peroxide spray seems to dry the rose leaves. I will try peroxide again but will spray earlier in the morning.

It is not just my imagination, the roses did bloom and grow more when I sprayed them with milk and garlic water. I used a weak milk solution to water my potted roses and the roses are growing well (I am doing this because I have not yet found an organic rose fertilizer that I like). The milk is suppose to improve the soil. I also water my roses with molasses water sometimes. Molasses is also suppose to improve the soil. The roses are doing well and are healthy. When I see a few diseased leaves I pull them off.

"Drying" the leaves is AKA burning them. Sounds like you should reduce the concentration of peroxide and be sure the rose are well watered before spraying. Early morning is best with most of the phytotoxic materials, and most of the organic sprays are phytotoxic in hot weather.

The same advice applies to baking soda. The concentration that is usually recommended is ~1 TB/gal. It is effective against powdery mildew. However, potassium bicarbonate is better.

Thanks Michaelg.

Tonytony2, Please give us the recipes for your hydrogen peroxide spray and molasses water and also tell us what kind of molasses you use...for example: blackstrap, sulphured or unsulphured?