Avoid pruning roses in the fall. Because pruning spurs more growth, stop deadheading or cutting blooms for bouquets a few weeks before your area's first frost date. As the weather gets colder, your roses will begin to go dormant, moving their energy reserves into their roots to help them survive the winter.
Deadheading should not be done after Labor Day to avoid encouraging new growth that may be damaged by early cold temperatures and to allow the plant to produce hips (fruits of roses that contain seeds). Many roses—especially old garden roses—produce large hips, which provide good winter interest.
Some are called self-cleaning and will not need any pruning. David Austin Roses should not be pruned the same as Hybrid Tea, Grandiflora or Floribunda roses. To allow your roses to harden for winter, stop deadheading and fertilizing around October 1.
In fall roses instinctively send their sap down into the roots so there is no danger of that. Deadheading interferes with that process and you run the risk of damaging the roses.
Stop deadheading hybrid tea, grandiflora, and floribunda roses in September. The spent flowers eventually develop into hips (fruits). The development of rose hips slows plant growth and helps prepare the roses for winter.
If you want to do any cutting of your roses in autumn, wait until after the first hard frost (temperature below 25 degrees Fahrenheit overnight). If you cut back before the first hard frost, it may send a signal to the roses to grow when they should be going dormant.
Fall: After the first killing frost, trim longer stems to keep them from snapping in winter storms. Keep rose bushes from being top heavy to protect them from being uprooted in strong winds.
For roses like the 'Knock Out', the Grumpy Gardener says, "About the only time not to prune is late summer and early fall, as this might encourage late growth that wouldn't harden off in time for winter." Regardless of which kind of rose you have in your garden, dead and diseased canes can be removed at any time.
Trim longer stems right after the first frost in the fall.
Again, it depends on the specific rose variety you are growing and your climate. For the most part, you can prune away dead, damaged, and diseased stems any time of the year.
To Prune or Not to Prune
There are several options: In early November, prune the top third out of plants to reduce and eliminate snow damage if we receive an early, wet snow. Do the finish pruning in the spring while the roses are still dormant but the chances of a hard frost are behind us (about late February).
This process, known as deadheading, is essential to cold winter care. So your rose plants emerge from the winter months ready to sprout new growth, you should deadhead any dying elements long before cold temperatures set in. If you don't see any flowers in need of removal, pruning rose plants is still a good move.
Winter is a good time to trim Knock Out Roses. While the plant is dormant, there is less chance of damage by disease and insects when pruning heavily. It is an opportune time to remove any large old wood branches and improve the overall shape of the rose.
Pinch or cut off the finished flower, just below where the base of the flower joins the stem. Leave any remaining buds or blooms to continue flowering.
Deadheading also helps your plants to produce new flowers since removing the old blooms stops the plant from putting energy into developing seeds and encourages it to make more flowers.
If your roses are growing in a fairly protected area out of harsh winds and extreme temperatures, wrapping with burlap or evergreen boughs will give sufficient winter protection. After the first hard frost of the fall, secure canes to their support and prune off long ends.
Cutting a rose bush down to the ground in the middle of Spring is a bit extreme. However, roses are amazingly hardy, so they may recuperate. I would just make sure they have enough water, and WAIT. Do not feed them, spray them, or anything, until they start showing new growth.
Watering your roses is still important during the winter months. Even if your area does not normally get snow or ice, cold wind and air can pull moisture out of the rose's canes – meaning the soil moisture can also be depleted. Check your soil on a warmer day and give it a light watering if it's needed – do not soak.
The first pruning, done in late January or early February, prepares rose bushes for the late-spring to early summer blooming. The second pruning is done in late August to early September and ensures shapely bushes with lots of flowers in the fall blooming season.
Begin feeding with rotations of fish emulsion, Epsom salts, iron, and a balanced rose fertilizer such as Grow More 10-30-20, Dr. Earth, or Kelloggs, or a granular product. A shot of SUPERthrive does wonders! October will be the last time to fertilize your roses for the fall growing season.