The best time to prune roses is when they are dormant around the end of June or July. Prune once the leaves have fallen and clean up the area around the roses by removing fallen leaves. Prune the roses bushes back to about a pencil thickness. Unless there is canker damage there is no need to prune any harder. By pruning to a pencil thickness you will achieve bushes that are taller and have an abundance of blooms. Try not to prune a rose too hard in its first two years. Once a rose has established a lot of old woody growth the flower production will be down as the sap cannot travel through the plant as well. Rejuvenate the plant by taking out the old woody growth, new growth with greater sap flow will be produced rewarding you with a bounty of blooms. Once pruning is completed spray the roses with lime sulphur and the ground surrounding the roses with lime sulphur to kill off rust and black spot spores in the soil.
SAP FLOW
Sap flow starts in spring and this is the time when rose farmers start to graft their roses. In some varieties of rootstock the sap flow can force the bud out of a newly grafted plant. Sap flow assists with delivering nutrients and water throughout the plant producing new growth. Throughout Spring and Summer sap flow encourages the new growth called Basal or water shoots that are red. The red shoots are quite different looking due to the plant producing anthocyanins a natural plant pigment which gives UV protection against DNA damage. Care must be taken to secure and protect these fragile shoots from wind and aphids. When pruning roses keep in mind that you are redirecting the sap flow and any dog leg shaped branches should be cut out to allow better sap flow.
WEEPING ROSES
Pruning weeping roses must be done with care. Weeping roses are made by grafting a small climbing rambling or pillar rose onto the top of a long cane of rootstock which will grow down the length of the cane. When pruning the weeping rose look at the shape and trim as required to outward facing nodes to encourage the growth of stems downwards along the cane. Keep in mind that too much leafy growth on top will create a haven for black spot so a little thinning on top will allow better air flow. Do not cut the long canes right back only trim as required maintaining the length. Once the weeper is established over a few years then cut out the oldest can right back to the graft union which will allow for new canes to come through.
STANDARD ROSES
Standard roses are made by grafting two buds from a Hybrid Tea, Floribunda, Grandiflora or other types of bush rose on to the top of a long cane that is 2ft, 3ft, 4ft or a higher rootstock cane. When pruning standard roses prune as though you have an umbrella upside down in the top of the bush. By pruning to outward facing nodes you will create a bush that will have an open area to allow air flow when new growth occurs. Too many leaves in the middle of the bush will encourage black spot and powdery mildew. Cut out any small twiggy branches so the energy is given to the larger branches. Keep a look out for both of the grafted unions being careful not to prune them off. When the rose has been pruned check the top of the support to ensure that it is still firm and has not rubbed into the bark causing damage. A small piece of garden hose slit down the side and put on to the top of the stake will protect the cane from damage.
BUSH ROSES (Hybrid Tea & Floribunda Roses)
It is important not to prune a new rose hard in the first two years of growth. Once the bush is established prune to a pencil thickness and try to shape the bush as needed. Roses along walkways can be trimmed to a side node rather than an outward facing node where it may grow a shoot outwards. Rose bushes planted together in the same bed can be pruned back from one another to allow better air flow. Once pruned spray with lime sulphur and clean up fallen leaves.
CLIMBING ROSES
Climbing roses should be pruned to a pencil thickness, on older mature roses the oldest canes can be cut out each year right back to the graft union to allow new canes to shoot from the grafted area. Older canes are less productive and sap flow is poorer. Large growing climbing roses can be cut back a little harder if you require bushier growth however, climbing roses growing in trees only need pruning down lower as it is the height that is needed to give the desired effect. Climbing roses can be left for up to five years before pruning however, pruning encourages flower production.
MATURE WOODY ROSES
Pruning can be done with a pruning saw. Good clean cuts are required in order to prevent canker forming so be sure to have a new or very sharp pruning saw. If relocating a rose then cut it back very hard to about knee high. Once planted there may be some die back in some canes but the bush will recover remarkably and the dead canes can then be cut out. Older woody roses once pruned benefit from a general tidy up by gently using a wire brush to remove older bark at the base. Removing the older bark around the graft union will assist with the production of new shoots through the hard compacted bark.
HERITAGE AND SPECIES ROSES
Pruning old fashioned and once flowering roses is best done when the bushes are dormant between June and July or on a as need basis pruning to a formal shape or left to have a spreading habit. The best way to prune this group of roses is to prune them like a hedge to allow flowering all over the shrub unlike a Hybrid Tea that bears it flowers towards the top of the bush. There is no real need to cut on an angle but where possible it is recommended. Some of the heritage and species roses are grown not only for their flowers but for their decorative hips so be sure not to prune at all late summer to allow the hips to develop. Some of the repeat flowering varieties can be pruned lightly after each flowering session. Overall pruning is about maintaining a healthy bush and shaping to the gardiner's taste and needs.
Scotch Or Burnet Roses - Spring flowering
Centifolia Roses - Spring flowering
Gallica Roses - Spring flowering
Damask Roses - Spring flowering
Moss Roses - Spring flowering
Alba Roses - Spring flowering
Boursalt Roses - Spring flowering
Portland - Repeat flowering
Noisette Roses - Repeat flowering
Hybrid Perpetuals - Repeat flowering
Tea Roses - Repeat flowering
Bourbon Roses - Repeat flowering
Rugosa Roses - Repeat flowering
Hybrid Musk Roses - Repeat Flowering
Tea Roses - Repeat flowering
China Roses - Repeat flowering
MINIATURE ROSES & POLYANTHAS
Miniature and Polyantha roses are pruned in June or July when dormant. They can be pruned with secateurs or with an electric hedge tool to dead head them however some gardiners prefer to cut them back very hard. Some miniature varieties grow tall such as Magic Carousel and should be pruned back by one third only to maintain height.
CARE OF PRUNING TOOLS
Pruning tools should be kept sharp as blunt tools damage the canes and crush rather than cut causing canker to rot the canes. General cleaning of tools is also a good way of maintaining plant health. A spray bottle with a dash of bleach is a ideal way of disinfecting your tools after pruning. Sharpening secateurs is best left to a professional however, there are small sharpening stones available at most hardware stores. Never sharpen the anvil of the secateurs only the cutting blade.
WINTER SPRAYING & MULCHING
After pruning, spray roses and the surrounding ground area with Lime Sulphur to eradicate Black Spot spores remaining in the soil. Spray again in Spring when the new growth starts, during the warmer weather black spot fungus spores are prevalent. A thick layer of mulch around roses is beneficial as it is harder for the Black Spot spores to reach the soil. Always remove fallen leaves from around the roses to lessen the chance of Black Spot entering the soil.
WHERE AND HOW TO PRUNE ON THE CORRECT ANGLE
