I would like to know when is the best time of year to prune back (heavily) the roses in my garden. I have read that winter is best, when they are dormant, but I have also read spring is the right time.
Also, with roses that are possibly 20 years old or more, and have very woody stems, is it all right to prune them back to the woody (brown parts)? Or should I not cut back past the green parts?
In the Pacific Northwest, most sources recommend pruning in late fall or early spring. Where to cut depends on the type of roses you have (modern, climbers, shrub, etc.).
The Seattle Rose Society also provides excellent pruning information.
You don’t mention what type(s) of roses you are hoping to prune, but the June/July 2011 Organic Gardening article by E.J. Hook, former gardener at the Woodland Park Rose Garden, covers basic pruning techniques for the 5 main types of rose.