Pruning of roses sometimes gives gardeners moments of dread. The fear of not knowing what to do can be increased by conflicting ‘how to do it’ articles in magazines and books. No two experts prune the same way and so different descriptions on how it is done can be confusing. Do not be afraid of how you prune, better to do some pruning than none at all. Best done in July in southern states or August in frost areas, and in the tropics February or March.
- Bushes – cut back by approximately one third to half its height. Remove all dead wood or old branches, which have not produced good growth or flowers in past season. Also remove twiggy growth thinner than a pencil. Thin out crowded branches. Remove the oldest branches keeping the younger branches, which produced the best blooms.
- Standards (or Stems) prune by removing 1/3 of the bush all over, trimming into a ball shape. Do not prune too hard but leave more side shoots than for bushes, and more flowers will be produced.
- Do not cut off any growth for the first 3 or 4 years as all are establishing their ultimate purpose – for arches, screens, posts or fences. Do not remove the long climbing canes as these will produce next season’s flowers. Once established the climbing growth will settle to produce flowers. Tie canes into position. Occasionally remove an entire cane if it has not produced good flowering during the past season and let a new cane fill that space. Cut back flowering spurs from the main canes to 2cm, cut off old flowers or seedpods.
- Shrubs are usually large so to reduce their vigour by cutting back hard will have the opposite effect with even more stronger growth and fewer flowers. Prune lightly and let the plants grow closer to their full size. Many heritage roses come under this method.
- Miniatures: Cut back by half their height.
- After pruning spray with Pest Oil, or White Oil, or Copper Oxychloride to combat over wintering fungal spores – blackspot, mildew, or rust, or insect pests.
- Apply fertiliser in late July or August then cover beds with mulch. Beautiful blooms will be your reward in around 8 weeks.
It sounds too easy but once you start with these methods you will see that basically all plants are covered by this style. Remember that you cannot go wrong and nature will cover any mistakes you may make. All roses have an ultimate size and by cutting back too hard they will keep trying to grow to their full potential.
Lastly, ignore all overseas pruning methods relating to cutting to an ’outward facing eye’ and at a ‘30 degree angle’. Do not ‘open out the centre’ or cut back very hard. All these methods are for Northern Hemisphere conditions where constant moisture, snow and ice and lower temperature are normal. In Australia we need to keep the middle of the bush covered to avoid sunburn of the plant and cutting at an ‘angle’ or ‘outward facing eye’ is just not critical.