I am hardly an expert, but I always spray my roses this time of year - whether new bareroots or established plants - with Volck oil after stripping off the leaves. I do worry that I may be losing beneficials this way (I keep an eye out for mantis egg cases) but by December my roses have so much blackspot that I want to get a fresh start. I do it on the bareroots, because who knows what is hitchhiking on them?

is this for real.. hope i could get this!

What is Volck oil?

http://www.scotts.com/smg/catalog/productTemplate.jsp?proId=prod180016&itemId=cat50080

It is 97% petroleum oil

[[by December my roses have so much blackspot

*** Blackspot isn't that common a problem in Southern California.
I've seen only 1-2 roses in my life that actually blackspotted all over here.
I removed them instantly.

We might see periodic rust or mildew -- but BLACKSPOT? No.
Maybe you have downy mildew?
Can you photograph affected foliage?

Jeri
Coastal Ventura Co., SoCal

I sometimes get rust, but that's rather uncommon. Mildew (powdery, mostly) does happen early on in the season. I know what those look like. I also know what blackspot looks like and I get blackspot, and sometimes quite a lot of it, by December.

I live near the San Gabriel mountains and we get a lot more rain than a lot of SoCal. Occasionally I see blackspot in early spring, almost never in summer, but almost always it returns in late fall. By December, there's quite a lot of it. I also get anthracnose during the same periods. It's not a bother during most of the season.

Jeri,

I actually get a fair amount of true blackspot by this time of year on some of my roses in coastal Santa Barbara. I do know what it looks like, and it's not cercospora or anthracnose. I also know what downy mildew looks like. Blackspot in our area does not cause the devastation that it does in other areas of the country, but it definitely is here. Yes, rust and mildew are much more common, but it's a myth that true blackspot does not exist in Southern California.

Susan