Although it's winter, some roses are still flowering so it may seem wrong to prune them. Winter pruning is done to encourage new growth and good flowering through spring and summer. The winter prune rule holds true for most roses but not for those that only bloom once in spring including many species roses. These and the winter bloomers such as banksia roses or ‘Lorraine Lee’ are pruned after flowering. With the exception of these roses, just cut off any late flowers and get to work.
Winter pruning is a hard prune, which means reducing roses by a half to two thirds while they are dormant. Use clean, sharp secateurs for this job. To protect yourself from rose thorns wear long sleeves, tough pants and stout gloves.
The best way to start is to roughly cut each plant all over. If a branch is hard to cut, try bending it towards you. If it is too thick for secateurs or hard to reach, use loppers instead.
Next use a pruning saw to remove old woody stems or stems that are badly affected by scale, cutting these off at the base. Also remove spindly growth and any branches that are crossing over.
Grab the secateurs again to finish the top of the rose. Aim to leave a framework of three to five main stems that have been shortened by cutting them to just above an outward facing bud.
If the rose bush has lots of suckers sprouting from the rootstock they must be removed. If there are one or two, just cut them off flush at the roots. If it is an ongoing problem there’s a drastic remedy. To remove problem suckers, dig up the bush after pruning then dunk it in a wheelbarrow filled with water to remove soil. Remove the sucker and the piece of root the sucker is growing from. Carefully replant the rose making sure the soil is firmed around the roots with no air pockets. Treat this rose like a new planting, watering it well through its first spring and summer.
A word of caution: don’t remove water shoots. These lush red shoots are not suckers but new stems that are part of the rose’s regrowth and arise from above the graft.
Other pruning tips
Clean up when you’ve finished by removing all the prunings (put them in the wheelie bin, not the compost). Spray the pruned rose and the ground around it with lime sulphur to control pests such as scale and diseases including black spot.
If cutting blades are dirty from old pruning work, clean with eucalyptus oil and a light-grade sandpaper. A spray of WD40 before use prevents sap from sticking. If the blades are blunt, sharpen them with a sharpening stone or fit replacement blades if available before you start pruning.
Always sterilise secateurs blades before starting work on the next rose bush. Use a solution of bleach or tea tree oil to wipe the blades.