PRUNING ONCE-FLOWERING ROSES
Old-fashioned non-repeating roses need to be treated differently to the modern repeat bloomers that tend to go dormant in the cooler months.
Cut once-flowering roses back straight after they flower.
The yellow/white Banksia rose is an example of a once flowering climber, so if you cut it back in winter you will remove all the flowers that are to bloom in the spring, and the flowers will not come again until spring the following year!
Some once flowering climbers flower on last year’s growth, so don’t cut those long canes that seem to be in the way, but rather move the plant if it is too big.
Cutting the canes may stop it from flowering. Only old canes that have produced well in the past but that now have diminished in flowering capability should be removed.
More below under “Pruning Old-fashioned Roses”.
WINTER ROSE PRUNING
If winter is here again, it is time to get out your pruning implements and give your roses a good prune. There is nothing more pleasurable than getting out in the garden and assessing the past year’s growth and determining the best way to prune your roses to achieve maximum benefit in the following year.
If you have repeat flowering roses, try not to winter prune them before July in most areas, before the coldest part of winter, as they may begin to shoot and all new growth may be lost if a frost then occurs.
” The best time to prune is in June or July. But if you live in a really cold area of Australia, then wait until early August so that the frosts don’t knock back the new shoots. ”
Summer can bring extreme temperatures. Look carefully at your stems to see if they have been burnt by the sun. Really bad damage may mean that the stem will need to be cut out. Sunburn to stems usually occurs when there is insufficient foliage to protect them, as when, for example, plants have been defoliated by pests or disease.
PRUNING LARGE FLOWERED BUSH ROSES
Assess each plant in turn before beginning the pruning process. Look for old stems that have lost their vigour, evident by their production of weak spindly growths. These must be removed at the base of the plant just above the bud union. A pruning saw is the best implement to use for this so that no stub remains. Remove at their origins any growths that are less than a pencil thickness.
Next look for any basal shoots (water- shoots) as these are very valuable and will form the basis of the plant for the next two years or so. If they are very young do not trim them at all.
Look carefully at the top of the basal shoot. It will be found to have a central section and usually two lateral sections.
Remove the central section leaving the two lateral sections. Trim each lateral section back to where there is a pair of tiny leaflets. In the angle of each leaflet will be a tiny bud. These buds will grow extremely well often producing magnificent blooms.
At this stage it is important not to cut into the main stem of the basal shoot as the buds on the main stem are immature and unlikely to shoot. It will be months before these buds will be ready to shoot by which time the lateral stems at the top of the basal shoot will have flowered and can now be removed.
Look at the remaining mature stems, these were once basal shoots but now have produced lateral branches.
Remove any growths that are crossing the centre or vertical branches. Retain only the younger branches that are spaced evenly from around the base of the plant. Shorten these branches to a well- developed eye that is facing outwards.
Do not worry if some branches (especially water-shoots) are taller than the others.
PRUNING MINIATURE ROSES
As for Large Flowered roses, it is important to remove all deadwood of which, there may be a considerable amount.
For cultivars that are less vigorous, reduce the height to about 10-12 cm.
More vigorous cultivars can be reduced to 25 – 30 cm in height.
PRUNING OLD-FASHIONED ROSES
Many old-fashioned roses form large shrubs and are typically found in large gardens. For the best display, they should be allowed to develop into fairly large plants.
Most blooms form on the side branches of stems, which may be large canes.
Remove any dead wood as well as old or weak growths.
Shorten young, healthy canes just enough to keep the plant tidy.
PRUNING REPEATING CLIMBING ROSES
Most climbers rarely flower much in their first year and only reach their full potential after about their third year.
Assess each plant to determine the relative ages of the canes.
Any dead wood, weak side shoots or old wood that has lost its vigour must be firstly removed.
Most canes over two years old will not be performing as well as the new canes so are best removed. It is essential to encourage the plant to send up new canes, so spent canes are best removed at their source.
Retain as many new canes as can be attractively arranged onto the fence or trellis.
Two- year-old canes will have produced blooms on side shoots. Cut the best of the side shoots back to one or two buds.
Remove any weak side shoots at their source. It may be necessary to untie the whole plant from its support and then retie the plant, arranging the canes so that they are horizontal or inclined slightly upwards.
If the ends of the canes are inclined downwards forming a hoop, the distal lower end of the cane will not produce blooms or only a few poor blooms.
Be careful when bending the canes as they may snap off at their point of origin.