Here is some important pointers for pruning antique roses. When
All once- blooming roses, should only be pruned after they have finished blooming in summer.
These old roses only bloom on last years growth, so if you prune in the spring or late fall, you will not have any flowers for the new season.
This is the best way to prune old roses: Remove about one third to one half of the years growth.
Then cut back flowering shoots to four or six bud eyes, and remove any dead and diseased wood.
Damask roses can suffer from dieback when their foundation canes are pruned. Avoid cutting into such major canes of these roses.
Time for pruning antique roses differ from region to region, with the best time being after the last frost, and just before, or at the time, when new growth appears.
In warmer climates, such as Southern California, where I garden, early January is the best time to prune roses here.
I believe you shouldn't cut back an old antique rose plant more than one half of last years growth.
Because, a rose that grows to 8 feet in height, and is cut back to 2 feet at pruning time, will spend most of it's energy growing back to 8 feet, and thus will produce a lot less rose blooms, which is not what you would want, right?
Pruning Repeat-flowering Antique Roses: Prune these old roses in late winter or early spring. Or follow the advice of Cynthia Dreiback written in 1922: When the forsythias are dressed in golden posies, Get out those secaturs and prune your roses.
Pruning Once Flowering Antique Roses:: Prune all once-flowering roses only AFTER flowering in summer. As soonn as possible after they have finished flowering.
Pruning Species and Wild Roses: These roses tends to be once-flowering,although they have a variety of growth habits. So pay attention to when and how they flower before pruning.Cut out the old non-producing wood and trimm back the remaining canes by a 1/3rd to 1/2 after they flower.
You can remove spindly and untidy canes in late winter, and lightly tri long canes at that time also.
Pruning Gallica Roses:
I recommend using sharp scissor action pruners for pruning your garden roses.
And a pair of long handled loppers will give you more leverage for pruning larger canes.
I also like to have a folding pruning saw that allows me to prune in very tight places.
You should also be equipped with a pair of good rose gardening gloves to protect your hands and forearms for the rose thorns.
Once you have finished pruning your old roses, remove any remaining leaves on the bush. It will cause the plant to go fully dormant, which is beneficial.
If you are growing roses in a region where stem borers are active, you should seal all cuts larger than a diameter of a pencil.
Sealing the canes with either white glue, or a non toxic compound formulated for roses, will prevent a stem borers infestation.
I find that Elmers Glue does the trick. This water based white glue works great, and it even dries clear.