Powdery mildew on roses in WA

I'm up here near Puget Sound and the climate is damp. I never water on the leaves of the roses and do mulch a fair amount. Now the first bloom is getting going and several of the roses have powdery mildew, or at least I think that's what it is - the leaves are a yucky gray. What to do?

Hi,
you could remove the affected leaves before it spreads, then spray the roses with a cup of milk diluted in a gallon of water. (and keep spraying every week and after rain).

whew, I was up late, last night. Here's some info I could have included, if I'd been awake :)

I use the milk spray on lilies, monarda (bee balm), apple trees, elderberries, squash/melons/cukes and anything mildew-prone around here, and that if your rose is already severly infected, Safer brand makes a sulphur soap that can get the plant back to a condition where the milk will be enough. I always use clean scissors to remove as much infected material as I can, and then clean the scissors right away. If the plant just insists on remaining infected, I replace it with something that wants to be healthy in our climate. It's hard to feel so ruthless, especially when it's a plant you thought would be really beautiful your garden, but it's actually less grief in the long run. With roses in particular, there are so many choices, I won't put up with one I can't keep healthy without extreme measures.


I like the milk solution because:
1) its ph is inhospitible to the funghi that infect plants, like the baking soda spray recipes out there
2) it hosts its own funghi and bacteria that are harmless to the plants but competetive with garden funghi
3) it's thought to nourish and strengthen the plants' immune system
....but it works best if you start spraying it *before* the plants are infected, i.e. back in Spring when it was raining almost every day around here, and spraying would have been pointless...that's where we go back to growing at least moderately fungus-resistant varieties.

The other reason I spray it on so many things, is so I'm never putting leftovers into the sewer system. I doubt that the small amounts I work with are really a problem, but I've heard that milk upsets the bacterial and oxygen balance in the sewer system. Dairies, who handle hundreds and thousands of gallons of the stuff, have to deal with that. So once I've sprayed everything I need to spray, I spray any leftovers on anything else it might help.

Ok ya, I pretty much always go off like this, when I'm awake :|
Lucky for you I have to go to church now.
Sorry. HTH,
Larisa





This message was edited Jun 25, 2006 10:33 AM