It's a little late to do anything now. You can remove all the leaves and destroy them to avoid any winter carryover. This winter, a spray of lime sulfur oil will act to destroy any overwintering blackspot spores.
Except to shorten overly long canes, I question why you're pruning now?
All the wet weather we've had in many areas has caused a big black spot outbreak on unprotected leaves.

Ok that was my plan, good. Although... winter? Did you mean Spring or to do it before the snow starts falling?

Because it's what my grandmother always does. Additionally, the roses that I've just figured out are climbers have gotten far too overgrown for what I want and I'll be reshaping them next year.

Are you not supposed to prune before winter? *dangit*

Nice to know it's not just me then :)

The instructions say to apply in late winter /early spring before or just as the buds begin to swell. It should not be applied when the leaves are opening as it can injure them.
I've heard of some applying it after their roses go dormant in late fall or early winter.

Here's the directions from the Bonide product:

DIRECTIONS FOR USE
It is a violation of Federal law to use this product in a manner inconsistent with its labeling.
Oil & Lime Sulfur Spray is a combination of insecticidal oil and fungicidal sulfur for use in controlling
rose scale, San Jose scale, black and brown scales, Italian pear scale, spider mite eggs,
mealybugs, overwintering fungus spores or plant diseases such as black spot, rust blights and leaf
spots on dormant deciduous roses, ornamentals, shade trees, almond, apple, cherry, nectarine,
peach, plum, walnut trees and raspberry bushes.
Apply in fall, winter or spring only when plants are completely dormant. Prune and destroy all old
leaves and branches of roses, ornamentals and shade trees. If applied in spring after buds show new
growth, injury may result. Do not apply when freezing temperatures are expected and do not apply
to evergreens. Protect painted surfaces from spray, as staining or bleaching will result if sprayed.
Shake thoroughly before using as separation may occur in bottle. Remixing reconstitutes the product
effectively. May be used in hose-end, tank or hand sprayers. Add small amount of water to
sprayer, add correct amount of Oil & Sulfur Spray, mix and add balance of water to the sprayer. Keep
mixture agitated while spraying. Wet pests and all parts of plant thoroughly with penetrating spray.
TO CONTROL OVERWINTERING PLANT DISEASES such as black spot, rust blights, leaf spots on
dormant deciduous roses, ornamentals, shade trees, apples, plums, prunes, and quinces mix and
apply at 4 1/2 times following table rates. For currants, gooseberries, grapes and pears at 7 1/2
times following table rates.
MIXING TABLE FOR CONTROL OF SCALE INSECTS AND MITE EGGS
AMOUNT OF OIL & LIME SULFUR ADDED TO AMOUNT OF WATER
5 tablespoons (2 1/2 oz.) ONE GALLON
8 ounces (1/2 pint) THREE GALLONS
16 ounces (1 pint) SIX GALLONS

BTW,
Pruning should be done in the spring. In our zone Mom Nature determines what pruning we need to do. Canes die from the tip down, a little more each time we get a bitter cold spell. Cutting back in fall leaves little for this to occur before you get into the heart of the plant. Unless you have the bud unions planted below the soil surface and the canes protected well, you take the chance of losing your bush.
A number of folks in really cold areas cut their bushes down to the ground each fall and rely on nature to protect the crown under the ground. I've seen it work but the bushes must have been planted properly in the beginning to do it this way.
I still feel safer just cutting back any extra long canes in the fall and doing my major pruning in spring. Most rosarians advise doing it this way.
Where in zone 5a do you live?

Ottawa, Canada. We get rather cold winters in our little valley.

I do, however, have lots of leaves and burlap that I'm ready to use. I was originally planning to leave the climbers mostly alone, but since they are COVERED in black spot I decided that it all needed to go >.It's just what my grandmother always does, cuts them down to about 6 inches long and then covers with soil or leaves.

Where do they sell lime and sulphur. I've been looking for years. Is it possible to mix up some from powdered lime, sulphur and insecticidal oil?

Garden centers, Lowes, Home Depot, Google "Oil & Lime Sulfur Spray" and get a list of on-line sites, and many hardware stores. My local Ace Hardware sells it.
I don't recommend attempting to mix it yourself. Too much of any ingredient could cause severe problems to yourself and your roses. This is not a benign product.

Is that stuff green? I'm trying to run as green a garden as I possibly can >.Not a deal breaker if there's no such thing but would definitely be helpful

Thanks, Karl. I'll go look tomorrow

It's insecticidal oil and fungicidal sulfur, both considered organic. It kills by smothering the insects and the sulfer wasone of the first fungicides. I suspect it's as green as Safer's insecticidal soap.
Greener is nothing at all.

Heh, sure but nothing at all leaves me screwed over :D

Sounds good enough for me.

Karl--I was planning on using Lime Sulfur this Winter after everything goes dormant because of the high amount of Blackspot and Powdery Mildew I ahve had this year. I have neverhad fungal problems like this before and didn't need to do the dormant spray routine, but this year has been totally different and I don't want to start next spring already behind the 8-Ball fighting Blackspot again.
I read the instructions on the bottle to use the product at 4 1/2 times the normal amount when spraying to kill overwintering fungus and insects, but found it really hard to believe it would be okay to spray it that strong and not kill the bushes themselves as well.
Karl have you tried the Lime Sulfur at that strength with success in the past?? It says not to apply when freezing, but that is pretty much what I would be doing, so that doesn't make alot of sense to me somehow.
Do the bushes have to be completely dormant to spray?? That would mean freezing temperatures, right??
Anyway, thanks for your information and I hope you see this posting and can answer my questions as well.
Thanks,
John

John
All the rain, overcast skys, and cool temps have caused moisture to stay on the leaves longer than normal. This is why blackspot has been a problem that many normally don't experience.
I posted Bonide's label as a service. I've only used it once and that was a really long time ago. I used it at the 4 1/2 times regular dose as directed with no adverse affects. Just make sure it's mixed well.
4 1/2 times the regular dose would be a little less than 1 1/2 cup per gallon of water or 11 1/4 ounces mixed with 128 ounces of water. Considering most will run off onto the ground, what's left on any leaves still on the bush will probably cause those leaves to drop. If sprayed on green leaves in spring or during the growing season it will cause leaf drop. The purpose of the spray is to coat any over wintering insects to smother them and to kill disease spores. I don't think the mixture is too strong for the purpose intended.
I think you'd be applying it after a freeze, not necessarilly when it's actually freezing. After a rose bush goes dormant, temps over 32 degrees won't cause it to stop being dormant. There's more to dormancy than freezing temps. Shorter days with less sunlight hitting the bush also is a big factor. It isn't until late winter and spring reverses this process that the plants will come out of dormancy
You can spray in December, January, or mid February on a day in the upper 30s and still meet the requirements. Just don't spray in freezing temps.

Here is more information in a thread from earlier, ? about dormant spray. I've never used it, but with other discussions, I always thought that late February would be a good time, although I would rather wait until after pruning. But by then, I have plants that have leafed out, and would have to weigh whether I would want ot lose the new growth or not.

Some folks have also used Daconil (now Ortho Rose Pride fungicide) or mancozeb as their dormant treatment. Others, like me, don't do anything as a dormant treatment, but I make sure to start my treatment program a week or two after pruning in late winter.

Syrinth,

I have the same problem you do. I am also a teacher and the past few months have been very busy. I went out into my back yard yesterday for the first time in 2 weeks and almost everything but the china roses were infected with blackspot. A few are almost completely defoliated. I sprayed with Bayer Disease Control for Roses and guess I am going to have to use it till the temperatures really cool off. I am a little confused about using dormant oil spray as none of my roses ever go dormant in our so called "winter". Should I just use bayer every week and then cut back to every 2 weeks till the BS gets under control?

Thanks!