If you live in a northern European climate, autumn is the time to start preparing you roses for winter - even though many rose varieties will continue to bloom until October or even later.
Preparation would normally start at the end of the summer by no longer dead-heading or applying fertiliser, and allowing the rose hips to form. This will help to discourage new growth, and allow existing growth plenty of time to harden-off before winter.
Although many roses, including most Shrub roses and Old Garden roses, will require little or no winter preparation or protection, this will not always be the case the further north you are. In fact in the very coldest regions where roses are grown you may need to give your roses an early winter prune to make it easier to apply you chosen winter protection.
The more tender varieties that are likely to require protection will include the Hybrid Tea and Grandiflora roses. In particularly cold regions they should at least have the graft union and roots protected from the changing winter temperatures. At the very least, a couple of layer of ‘frost-protection’ fleece will probably do, but of course more drastic measures may need to be taken depending on where you live. On established plants this can be achieved by mounding soil over the crown and lower stems to a height of 8-12 inches. However, don't scrape up soil from around the plant as not only will this will damage fibrous roots it will also expose them to the cold.
For added protection, consider piling straw or dry leaves around the base and the stems of roses. This ‘mulch’ can be kept in place with chicken wire - or something similar - and secured by small stakes. Come the following spring the mulch and soil mound can be gradually removed as the weather warms up.
If you would like to try and do without the palaver of protecting you roses from cold damage you could always try planting those varieties that display the best cold hardy tolerance. Below have been listed some of the best.
Rosa ‘Maria Stern’
Rosa ‘Arctic Flame’
Rosa ‘Dr. Brownell’
Rosa ‘Dr. Brownell’
Rosa ‘Senior Prom’