I am in the low-Hudson area. We have one heavy snow at the end of October. I have a lot of tall shoots that I would like to prune them down to prevent the further winter damage. I am curious if it is the right time to do fall pruning?
I believe it is if your roses have gone dormant (are no longer growing).
Here we prune anytime from now until February, but we have roses that NEVER go dormant because it never gets cold enough.
I would not take off any more cane than you have to to prevent breakage at this time, better yet if you can just secure them to prevent them from flapping around rather than pruning. I always try to wait on the pruning until spring. Here, the forsythias bloom sometime in late Feb or early March and that is when we do a main pruning.
If you prune a lot now it will encourage tender growth to form that will be winter killed. You'll also have increased die-back of the cane, relative to if you'd left that length on.
I agree with stlgal's posting. I just never prune in the Fall. If you're worried about wind damage to long canes, I suppose pruning could help - but I've never seen wind damage in my zone 5 garden. If you're worried about cold damage, I agree with stlgal that pruning is likely to produce greater dieback of the canes.
I have a couple of roses that I do a "snow tip pruning" on every year because they have stiff canes and if we have a heavy snow are liable to breakage from the weight of the snow. The goal is to remove as little plant material as possible, but also to open up the canopy so that it doesn't catch a lot of snow and cause breakage. In a way, you could call it "lacing" the top of the rose.
We had an early snow this year and I hadn't done my snow tip pruning and one plant was bent over to where the top of the plant was almost touching the ground. I went out and shook the snow off at 10 pm and hoped we would not have more snow that night. The next day I did the very light snow tip pruning and I doubt if I will have any problems with breakage.
I never take the rose down to where I would prune it in spring. I'd just rather decide how far down to prune it than to allow nature decide for me.
Watching for when the forsythias bloom is a great rule of thumb. Growing roses in my area is complicated by microclimates and I've found that the forsythias bloom across town at least two weeks before my forsythia blooms. So, I wait for mine to show color before I do my real pruning.
We likewise have microclimates and an urban heat island effect here, so I always generally note what's blooming in the city proper but wait to actually prune my roses until the forsythia in my suburban garden are in full bloom!
Another option you might try is something I adopted especially for my newer, small roses, but now that I've figured it out, will be doing it for my larger roses as it applies. My z8 mountain home is not nearly as cold as you are, but (knock wood) we usually get 2 dumps of 3'-4' each winter which eventually becomes one giant ice pack in the garden. As the block melts, canes can get stripped off or broken.
So last year, for the little ones, I put a 4' stake next to them, stapled a piece of green tie tape at the bottom and spiral wrapped it around the stake and put another staple in the top. For the babies, the stake also helps them not get stepped on, especially by the dogs, all year round. Wasn't that hard to take the tape off last spring. I'm running late this year and plan to do it over Thanksgiving as well as the bigger ones along the chain link using the fence instead of the stake and simply tying up in a zig-zag to the fence.
A lot of the damage that was done by that early snow fall was because the roses were not dormant and still had their leaves. It was the weight of the snow collecting on the leaves that caused them to break. Once they're dormant and the leaves are off the canes will shed snow and not break. Wait until spring to do any major pruning. In the spring the rose will tell you where it needs to be cut too by where it sends out new growth. If there is something very long and likely to whip around in the wind cut that to about 4 feet. Then put a stake next to the taller roses and tie them as bundle to the stake so the canes don't blow around and/or bend under snow. If the plants are upright growing you won't have much problem with the snow as it will just slide off. Spreading ones may bend down under the snow but will bounce back in the spring on their own for the most part. I've never experienced any severe damage from snow. Actually I like a good snow cover because it's the best insulator for them.
I live in Central Illinois. Right now we've had 1 freeze. I will go out in December and shorten the tall canes to 4' just to stop them whipping in the wind. That is the only pruning I do in the fall.. I have not started to put on my winter protection yet.
In our climate, heavy wet snow can be expected to snap a few canes during the winter--but we are talking about over 200 rose bushes in our yard. Wrapping the bottom foot or two with burlap is an effective way of protecting roses from rabbits and winter. I used to stuff the burlap with wood mulch, until it froze too early one winter--the protection was just as good--perhaps better, since fungal diseases are less of an issue without mulch. It has been years since we lost a rose.