|How much should I prune roses for winter and how much should I protect them from frost.|
|The answer to your question depends on what kinds of roses you are growing. The best winter protection is to plant roses that are grown on their own roots rather than grafted and to plant only roses that are considered reliably winter hardy in your zone. With roses like that, all you need to do is mulch over the root area in late fall once the ground is frozen. If a severe winter damages the top growth, these roses can regrow successfully.
If you have grafted hybrid tea roses, they should be planted so that the graft union is several inches underground. This is done to protect the graft from extreme cold as well as from oscillating temperatures. You can cut back the longest canes partway so they are less likely to whip about in the wind. (Additional pruning is typically done in the spring.) Then pile a cone of garden soil over the base of each plant, make it about a foot tall. Also mulch over the surrounding root zone with about six inches of organic mulch. Do this in late fall -- November or December when the plants have stopped growing and the ground is frozen.
In the early spring, begin gradually removing the soil from the base of each plant. This will allow it to wake up naturally with the season. You would also trim off any winter damaged canes, cutting back to live wood, and then pruning for shape or to thin out the oldest canes. You might want to contact your local consulting rosarian or local chapter of the American Rose Society for more detailed assistance. There is ample rose care information as well as contact information at the following web page. http://www.ars.org/ Your local county extension may also be able to assist you. It would be helpful if you can tell them which particular roses you planted.
Good luck with your roses!