Powdery Mildew Best treatment for JM

Have any of you had to treat your JMs for Powdery Mildew? What do or did you use?

this happens on a couple trees I have - interested to here comments

Take a look at the hydrogen peroxide section. My brother tried it on maples and he was very pleased with it.

http://urbangardenmagazine.com/2009/08/how-to-beat-powdery-mildew-in-hydroponics/

Thanks Dave, valuable info from that link...much appreciated.

thanks dave.

Thank you very much Dave.

I did the H2O2 treatment with drug store strength last weekend. Hoping it worked but I can't tell because all of the leaaves still look the same as in photo, still powdery. Is this what I should have expected or should the treatment/strength have 'removed' the mildew?

I have not seen p mildew on these trees before and this only began to appear several weeks ago when as I recall days were warm, nights cool and dry with no rain to speak of and me bottom watering once or twice.

So, my remaining questions for now are 1) Did treatment work? 2) How susceptible are JMs ?
And, is there a powdery mildew that specifically attacks JMs ? Are some types of JMs more sensitive to poor air circulation/powdery mildew than others?

It all depends on your climate but I have seen it attack all Japanese Maples. My brother said it worked to his satisfaction, whether how quick I do not know. From my experience the mildew comes when there is a lot of moisture. So an airflow could help to subdue the problem. I know this is not what you want to hear but in the end of the year the leaves will fall off from the frost which you should have gotten a nice freeze last night. I know I did. So by the end of this week the leaves will no longer be a problem.

I have used for my production Cleary 3336 which I find to be very effective. Now this is the chemical solution of which many people don't like to use. That is why I submitted the environmentally friendly solution.

http://zapthemcritters.com/cleary-3336f-fungicide-quart-nufarm.html

Dave I really appreciate your replies on this.

Not concerned about the leaves this Fall but do want to do what I can to lessen any mildew problems for new leaves next Spring.

If I 'knew' that I had killed' as much as possible before spores got every where I wouldn't bother. I do read that clean up of infected leaves is important to control but am quite daunted by the prospect of that task as my yard is nothing but leaves of various sorts and I mulch and winter protect with leaves. If diseased leaf disposal is not necessary, I'd really like to spend my gardening energy elsewhere!

Perhaps you or others could suggest a preventative treatment that could be administered in spring to protect next years leaves as they emerge? Or?

And since you are a 'neighbor' does the powdery mildew infecting our native Dogwood also attack JMs?

I really do not know about different varieties of powdery mildew, if there is a difference they all look the same to me. I really never bothered about collecting any leaves that might have been affected. When I was dealing with 100's of thousands the thought of collecting and disposing of the leaves would be a task I just don't think I would have been up to. Just make sure that you don't over water the maples and have a good air flow.

This may help you out some. Good luck and happy growing.

http://county.wsu.edu/asotin/gardening/general/Documents/RoseCare/PowderyMildew.pdf

Again, thanks Dave.

As to 'good air flow' The last few years I have wished for something like a "whole yard fan" that would quickly exhaust that sticky humid air from the premises! Oh yeah, one that could be zoned to dry off wet foliage before sun fall or night fall!

This seems to effect only some trees for me and it almost never shows in spring. Usually in hot humid summer weather but humidity is the key. Most fungicides will work well but usually those effected leaves will drop but new ones be ok although usually sparce . If you spray seven for Japanese beetles just add some fungicide to your mixture and that should get rid of it or greatly help. Spray a few weeks before the beetles come out and use spreader sticker to insure that it is not washed off by watering or rain or dew. repeat every two weeks during beetle season. if you are doing green house growing ventilation is the key. But using fungicide is always useful in or outside the greenhouse . Don't know about Hyd. Per. use it on a plant you don't care about if no damage then use and see. I don't think you can use with spreader sticker with HP since it evaporates easily...so that is a BIG drawback as far as rain dew and watering is concerned unless you want to constantly be re-treating it over the hot humid days of summer.

This message was edited Dec 24, 2013 3:01 PM

I have a Japanese Maple, Waterfall, which had a big branch from another tree fall on one of it's trunks about 4' from the ground. it has left an ugly scar where the branch was ripped out of the trunk. This happened about a year ago and I haven't done anything to the scar yet. The tree seems healthy now but I am worried about a Fungus or bacterium getting into the recessed scar.
Should I cover the area with some sort of tar product, or just let it alone? please advise.

I would say let it heal on its own - have had several here get hit with ice storms and all have bounced back after I trimmed off the damaged branch's.