Sorry for butting in, you might want to give organic Greencure a try first before the shovel...Since you like the rose and its the only rose bush getting PM...Just throwing the option out there for you...Hope it all works out for you whatever you decide!

http://greencure.net/

http://greencure.net/powdery_mildew_on_roses.asp

I've used it with success on powdery mildew but it does nothing here to help blackspot...

I am in zone 5 Chicago area, and I do not have a problem with mildew at all with my other 100-plus roses. My question is really not so much what to do about it as it is: is the antique variety Leda so prone to mildew that I might as well give up on it without spraying? This is the second season it has broken out on every leaf.

If Leda breaks out next year I'd say its prone in your area to PM and if you do not want to spray anything then replace...

I've never heard of Leda having mildew problems, though I've never grown it. The only roses I'm aware of having serious mildew problems in a humid climate are multiflora hybrids. Sometimes it shows up randomly if a rose is planted in a particularly hot, dry microclimate. To completely overgeneralize, while blackspot is a disease of too much moisture, powdery mildew is a disease of too little. So a small rose has the possibility of growing out of it as the root system matures and can move more water. Rinsing it off every day for a week has been known to help.

It is, of course, your decision what to do about it. If you got it as a band, or anything other than a 2 year old bareroot, I'd recommend giving it another year, possibly two, just to see if it grows out of the problem. Something else you could consider is moving it to an out of the way spot if you have one. Then you can visit it when it is blooming, and ignore it the rest of the year. That is what I should have done with Madam Hardy, but those place are overrun by various species roses....

I've never had mildew on Leda but my conditions are different than yours in the hot and humid south.

I live in a hot, dry climate, and The Fairy is the only rose I've ever had mildew trouble with. I agree that mildew is a problem of too little moisture, not too much. This became evident to me when certain perennials mildewed in my garden until the water system was improved (we irrigate regularly here). Though Chicago is not exactly a desert, make sure Leda is well watered. I had some improvement with The Fairy when I used the baking soda, antibacterial soap, water treatment on it regularly. My formula for this treatment was a tsp or so baking soda, added to a quart of water, plus a spritz or two of liquid antibacterial soap. Combine well, and spray on the plant. I just used a little household plastic sprayer. I wonder if The Fairy is in Leda's parentage, or vice versa). I wouldn't give up on Leda yet. Diane

Diane, if anything I think it would be the other way around. The Fairy was introduced in 1932 & Leda pre 1827. I tried growing The Fairy for 4 yrs, I loved its' shape and blooms but it would go through horrible cycles of blackspot, I do miss it.

Jane

It wasn't mildewy HERE. (It also didn't bloom, but that's another issue). But that doesn't mean it wouldn't, in your conditions.

All of this stuff is so LOCAL.
If it's the only rose that mildews for you, then it's mildewy in your conditions.