Winter is always a busy time in the rose garden. Bare root planting continues through June and July and should be completed by mid-August. On the Adelaide Plains rose pruning is carried out in July, and should be completed before the plants begin to sprout new growth. In colder areas it is wise to prune in August to avoid frost damage on new shoots. When preparing for the pruning season it is wise to obtain long leather gloves, secateurs, pruning saw, long handled loppers and knee pads. All cutting equipment should be clean and kept sharp. To complete your pruning gear, a belt with a pouch to hold your secateurs is a wise investment.
Pruning Hybrid Tea and Floribunda Bush Roses
Before you begin, thoroughly examine the plant, checking for dead wood, spindly wood, crossing branches and the suckers which grow from the rootstock of the plant. Then proceed by cutting away dead wood and spindly shoots which are less than the thickness of a lead pencil. Crossed branches are next to go, but I do not stick rigidly to this if the branches will not damage each other such as when they cross close to the base of the plant. Remove shoots which crowd the centre of the bush. Then shorten back the remaining branches by about 1/3 and cutting to an outward pointing eye. The eyes are found at the base of each leaf. It is wise to check for and remove suckers from the understock if they are present. Suckers must be totally removed by digging down and removing them from the understock or roots and do not cut off at ground level as this will just encourage much more new unwanted growth.
Pruning Climbing Roses
These roses can be trained to grow flat against a fence or wall or vertically on a post. The fence or wall should have horizontal wires fitted 400mm apart to act as supports for the climbing canes to a maximum height of 2 metres (to avoid the use of a step ladder). The pruning process begins at the base of the plant by removing dead wood and canes which have flowered in the previous spring. All of these can be removed if there is enough new growth to cover the fence or wall. New canes do not necessarily all grow from the base of the plant, some will break from the frame work of the previous year’s growth and naturally the pruning cut is made to free the new growth from that which has flowered the previous spring. If there is insufficient new growth to cover the support structure, old wood can be retained by cutting the flowering shoots to two eyes. The new canes should be tipped (removing about 300mm) then tied horizontally on the wire forming the shape of a fan. The centre of the fan is the hardest area to fill and it is usually necessary to train shoots vertically to do this.
The pruning of roses on a pole is totally different. The support posts should be about 2.5 m high and pruning is carried out by firstly removing the dead wood and growth which has flowered in the previous year. The growth which is left is then tied vertically and some canes are terminated at 0.5 metre height, others at 1 metre, others at 1.5 metres, and/or 2 metres and/or 2.5 metres. By doing this the sap will run to the highest point on each cane stimulating the terminal eye (bud) to sprout and as the canes have been trimmed to variable length, the whole pole will be soon be covered with flowers.
Pruning Standard and Half Standard Roses
These roses are pruned firstly by removing the dead and spindly wood then removing the crossing branches, and finally shortening about a third of the growth from the remaining shoots by cutting to an eye which gives the new growth plenty of space to flourish without being damaged in the high winds. Aim to have shade on the crown of the standard by deliberately cutting to two or three inward eyes. This prevents scorching of the crown in hot weather.
Pruning Weeping Standard Roses
These types of roses are pruned to leave the new growth as long as possible to allow it to flower towards the ground. If there is enough new growth, then the older shoots could be completely removed. Canes which are two or three years old can be retained, if the annual growth is not sufficient, by cutting flowering shoots to two eyes.
It is much easier to learn pruning techniques by attending one of the pruning demonstrations which are arranged by our Society. There you will be able to prune under supervision and thus gain more confidence in your technique.
When pruning is complete, remove all the pruning off-cuts and leaves. Do not add them to your compost as this will only aid the spread of disease. After this is done, spray the rose plants with a fungicide such as copper oxychloride or Bordeaux mixture (with a wetting agent) which will help prevent infestations of black spot and mildew. At the end of August plants should be fed with “Sudden Impact for Roses” at the rate of about a cup full per plant, and wait for rain to carry this to the root zone.
Plants should break into growth towards the end of August and from small shoots to leaves in early September. These can be small homes for hatching aphids when the weather begins to warm. Spray at peak infestations with insecticide but not when bees are active. Preventative spraying with ‘Triforine’ or ‘Mancozeb’ should begin in mid-September to check black spot and mildew. New growth should escalate towards the end of the month setting the scene for the peak spring flush in October.
By Walter Duncan