IF it's winter, it's rose pruning time, at least for most of us and for most roses.
To be precise, it's time to prune roses that will bloom on the fresh, new growth that will then appear this spring. These include the modern hybrid tea roses, the cluster-flowered floribundas and the David Austin-bred roses that have the shape and scent of heritage roses but the repeat flowering, tough characteristics of modern roses. Many of the once-blooming old-fashioned roses are pruned after flowering, in most climates in late November.
The principle of pruning is the same for most plants: you are seeking to promote flowering, taking care not to remove flower buds that are forming. While most roses bloom on new growth, some flower on second-year wood, growth from the previous season.
When you do prune, using sharp secateurs held so that the section left on the plant is cut clean, first remove any diseased or damaged wood, right back to a healthy joint. Take out any crossing branches that may rub on others, creating wounds that encourage disease, along with old, unproductive wood. You are pruning also for shape and to create a shrub open enough to allow air to circulate.
Make cuts about 6.5cm above a bud, or eye, so that it will develop a new shoot in the desired direction; cut on a slant away from the bud so moisture will drain towards the base of the plant.
If space is limited in your garden, you may concentrate on climbing roses to dress vertical structures such as walls and fences. To encourage the greatest flowering from climbers, with blooms all the way along the stems, tie them down flat -- as horizontal as possible -- to promote stress, and shoots, all the way along the branch. After flowering, cut back to one or two eyes to encourage repeat flowering, then tip-prune the water shoots in autumn or winter. Or plant multiples of the one rose and tie canes in repeating S patterns to encourage dense flowering. With climbers that shoot from the base, cut out long, spent canes from soil level, just as you would the long canes of may, philadelphus or weigela.
To encourage roses to flower right up a pole -- particularly useful for those who garden in a small space -- prune to encourage each shoot to develop in a different direction. Or place tripods covered in two different roses -- perhaps an intense pink 'Bantry Bay' teamed with a softer 'Blossomtime' or 'Kathleen Harrop' -- in a border of perennials to create height and to break up a large space.
Prune standard roses to promote several long, drooping arms: weigh them down with rocks to encourage each branch to grow downwards, rather than horizontally, for greater flowering.
Don't prune too early if you live in a frost- prone climate as you don't want the plant to shoot too soon, when there is a risk of damage to young, fresh growth. Most of your roses will be grafted on to an understock to suit the climate in which you garden: watch for any shoots from beneath the graft, which, if left, would take over from the desired plant. Remove them at any time of the year.
After pruning, spray with lime sulphur in warm temperate climates or copper oxychloride in colder climates, then with horticultural oils to combat scale. Feed after pruning: several companies manufacture a potassium-rich fertiliser formulated for roses. Then comes deep watering and mulching.
Winter is also the best time to buy roses, when the large growers and nurseries sell bare-rooted plants. And don't put the secateurs away once you have tidied up the roses: it will soon be time to prune the hydrangeas.
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PRUNINGS
- Dip secateurs into a disinfectant bath between rose bushes to prevent the spread of any diseases from one bush to the next. And don't place rose prunings into the compost or green waste bin.
- While roses love nutrient-rich clay, they also demand good drainage; you can improve heavy clay by adding compost and mulch. Orbuild up garden beds to ensure perfect drainage.
- You will learn a great deal more about roses at the Ninth National Conference of Heritage Roses in Australia, to be held at Victoria's Mornington Peninsula from November 14 to 16. A raft of Australian and international speakers will address the central theme, Keeping History Alive, and workshop presenters will cover many aspects of rose history and cultivation. An added treat will be visits to six stunning local gardens that feature old roses. It will be a weekend to immerse yourself in the beauty and versatility of these wonderful plants. More: (03) 5974 4333 or visit www.heritage.rose.org.au.
Article from: The Australian |
