There are two main groups when it comes to climbing roses – those that only flower once in spring and those that repeat flower from spring till autumn.
Spring flowering roses
Spring-flowering roses include old-fashioned favourites such as Dorothy Perkins, Albertine and the banksia rose. These are not pruned now, but rather after they finish flowering, around November or December, when they can be pruned hard to get their size under control. Pruning at this time will actually prevent flowering. You can actually leave them for many years without pruning them at all, however they then get very large and out of control, so pruning them hard every few years will help to keep them tidy.
Repeat flowering roses
Repeat flowering climbing roses such as the ever popular Climbing Iceberg, climbing Gold Bunny and climbing Pierre de Ronsard are pruned in July, as are bush roses. By pruning them now we encourage the rose to produce new wood and this is what will flower for us starting in spring and continuing through till autumn.
Just as with bush roses, you need to be prepared, be dressed appropriately, have good gardening gloves and the right tools – sharp secateurs, loppers and a good pruning saw. You will also need a rag and jar with diluted bleach, or a rag soaked in tea tree oil, to disinfect your tools between roses. As a general rule of thumb, there is no need to prune climbing roses for the first three to five years. Simply trim and train them, tying canes into position horizontally as this encourages flowers along the length of the stem. After this time, they are pruned annually.
Step 1. Untie the rose from the structure it is growing on. Rather than train your roses through wire mesh or lattice, it is better to simply tie climbing roses on to the front of their climbing frame. Then when it comes to pruning time, you simply undo all the ties, prune out the growth you don’t want and re-tie the remaining laterals into position.
Step 2. Start by pruning out any dead wood.
Step 3. Cut back approximately one third of the canes to the ground or to a strong young branch, starting with the oldest or crossing canes first. This means that if your climbing rose has 6 canes that arise from the base, you completely remove two of them. The colour of the cane indicates its age, with new wood looking light green and fresh, darker wood is one year old, and old brownish limbs are three or more years old.
Step 4. Once you are left with the canes you wish to keep, remove any twiggy side branches off these canes, any strong laterals that bore last year’s flowers, and the thin tips of new canes.
Step 5. Once the rose is pruned, train branches horizontally as this will encourage them to flower along the length of the stem. An upright stem will generally only produce flowers at the end. When tying climbing roses always use a soft flexible material, such as strips made from pantyhose or t-shirt material, rather than the plastic coated wire plant ties as these can cut into the bark if not maintained.
When dealing with roses of any kind, it is important that you look out for suckers from the rootstock, as if left unattended, they can weaken the rose and eventually take over the whole plant. They are vigorous shoots which appear from below the graft union and should be removed immediately from their point of origin. Most roses in South Australia are grafted onto Dr. Huey rootstock, which has pale green foliage and if allowed to flower produces magenta-red, semi-double flowers, but only in spring with no repeat over summer and autumn. Ideally they should never be cut as this simply encourages them to branch more. They should be pulled off with a heel which will hopefully scar and prevent them from re-appearing.
Rose suckers from the rootstock should not be confused water shoots which are also vigorous growth but these appear from above the graft union. They are healthy new canes, often purple in colour and are full of goodness which will benefit your bush in the future. Bend these water shoots down horizontally and tie them to keep them in position.
As with the pruning of bush roses, after pruning, clean up around your plants, removing the old leaves and prunings.