Practical Tips for Rose Pruning
This article was first published on 26 Jun 2014.
Pruned roses in the Rose Garden
It’s time to start thinking about pruning your roses. The general rule is the colder the climate, the later you prune in winter.
At Dunedin Botanic Garden we prune modern roses in late July, when they are at their most dormant and hopefully the heaviest of frosts have passed.
Pruning, at its simplest, is the removal of old, weak, spindly growth and the shortening of flowering stems, to encourage new growth. It opens up the centre of the bush, to allow more light and air movement.
- Use clean sharp tools.
- Choose a dry day, with some air movement.
- Remove the 3Ds – Dead, Diseased and Damaged stems – cutting off cleanly at the base or a suitable outward facing bud.
- Open up bush –remove inward facing growth and side shoots.
- Select and retain 5 to 7 healthy canes evenly spread around the base and shorten by half to one third.
- Make cuts on a 45 degree angle, sloping away from the bud.
- Carefully scrub around the base afterwards with a wire brush to remove any moss and old bark; this stimulates desirable new growth from the base.
- Clean your tools after cutting diseased wood, and between bushes to prevent spread of diseases.
- After pruning, apply a spray of copper and oil at winter strength, spray around bud union to destroy over-wintering diseases and insect eggs that tend to hide at the base.
Rose pruning demonstration Saturday 19th July, 1.30pm. Meet at the Rose Garden or in the information centre if raining.
Linda Hellyer is curator of the rose garden at Dunedin Botanic Garden.