I got Grandmother's Hat in Aug '07, so 3 years. And I do have 4th of July, actually 4 of them, and it does not mildew, but it does rust once in awhile in the season. I don't have the others on your list. That said, I exaggerated a little when I said everything mildews here. I recently made a list for publication on the rose society site of roses that don't mildew here, and those were the following roses. Hybrid Tea/Grandifloras: Cherry Parfait (red/white) Frivolous Pink (pink/yellow) Lasting Love (red) Honey Dijon (gold) Stephen Rulo (lavender/brown) . . . Floribundas: Julia Child (yellow) Shockwave (brightest yellow) White Licorice (light yellow) Lovestruck (pink speckled) Playboy (orange/yellow) Gebruder Grimm (brightest orange) Kimberlina (pink) Perfume Tiger (yellow/pink stripe) Hot Cocoa (russet) . . . Shrubs: Darlow's Enigma (white fragrant hybrid musk) Dragon's Blood (dark red big shrub) Red Ribbons (red groundcover) My Stars (thornless dark pink) Rural England (reblooming pink rambler) Route 66 (purple) Mme. Plantier (white once blooming alba) . . . Climbers: Berries n Cream (pink/white stripe) Candy Land (pink/yellow stripe) Fourth of July (red/white stripe) Rhapsody in Blue (it's a climber for me -- purple) Blaze of Glory (brightest orange/red) . . . Mini's: Irene Marie (yellow with red picotee) Swedish Doll (orange/red) Sequoia Twist (orange/yellow stripe) Gourmet Popcorn (white polyantha-like shrub) Gingerbread Man (dark yellow) Gizmo (orange single) Hurdy Gurdy (red/white striped mini climber) . . . Everything else gets sprayed fairly consistently all year. Kathy

steve, lack of rain is the cause. The rain actually washed the mildew spores off the leaves. Are you overhead watering or using soaker hoses? You can try washing off the leaves of some of the plants. Earlier this year I had a lot of PM on my roses and other plants, despite the roses being sprayed with fungicide. Sometimes you can't beat it. It has subsided substantially since it has been raining regularly here. There is a product called Wilt Pruf that you can spray on plants that is supposed to help keep the PM off. Luckily PM usually doesn't do a lot of damage, it just looks bad.

Thanks, misswissa, that is very helpful! I'm not sure what watering from overhead is (I am always careful to not to water the leaves but rather the base of the plant) but it has been exceptionally humid and hot the last few weeks here. We've had a lot of rain. I bought some fungicide and treated yesterday, hopefully that will help. Yes, they are in (very large) containers...I wish wish wish I had a ground garden to put them in but sadly I do not. I figured it would be an experiment to do containers, even for mini-pumpkins...an experiment that may have failed already thanks to the powdery mildew, but I guess we'll see! One of my healthier plants has a flower that opened up just this morning...crossing my fingers!

I have used milk diluted 1 part -2 parts water as an organic method for mildew control on my squash and cucumbers. Sometimes it works but usually it just slows it down. That is why some of these vegetables do not grow through the summer/ But in weather like this it is hard to fight once it has gotten started. I do not water in evening but the rain has been coming down anytime it wishes. I doubt the mildew will kill the rockrose but it might not look to good until the weather changes.