Are your roses are looking a little shabby; black spot and powdery mildew running rife, blooms look battered and foliage quickly thinning? Don’t despair, winter is upon us and your roses are heading for a well-earned rest after a long and productive growing season.
Deciduous plants such as roses hibernate over winter, shutting down to recharge their systems in readiness for a new spring start. As the days begin to cool and daylight shortens, it triggers a mechanism in the plant, telling it to prepare for winter. Stopping the flow of energy means any existing leaves and flowers won’t be fed and are left to the ravages of disease and decay, which makes your winter roses look horribly tatty. This enforced dormancy helps protect the rose over the cold months of June, July and August that would savage any lush new shoots, especially in areas prone to heavy frost and snow.
Time to prune
Winter is pruning time, however, don’t be in too much of a hurry to give them a chop. Those keen to have an early spring display of flowers might be surprised to know the difference in blooming from a rose pruned in the first week of June, compared to one pruned in late July, may only be a few days. Resist the temptation of pruning early. Whilst ‘prune in June’ alliterates well, July is an ideal month to break out the snips. Your roses will be fully dormant and the sugars that normally race through the plant producing masses of soft growth have converted to starch, hardening up and giving the stems a lovely crisp ‘snap’ sound when cut. For those living in extremely cold areas, delay cutting back until mid August.
Rose pruning know-how
Pruning is often seen as a difficult job. Well, there are quick, easy and effective ways to make it happen. First rule – there are no rules, just guidelines. Reducing bush roses by half their height and around half the number of canes is a great start. Also, while it is generally good advice, don’t worry too much about pruning each stem to an outward facing bud and cutting at a 45 degree angle. Changing that has just saved you half your pruning time!
Even in July, your bush roses can have a good covering of leaves, especially if you’ve planted some varieties such as the Knock Out range, which are probably still in full bloom. I suggest grabbing the shears and clipping off any top growth to expose the ‘naked’ stems below, so now you can see what you are cutting. Start on the outside of the bush. Prune any large protruding canes and work your way around the plant, reducing its size and spread, then head inside. Look for any obvious old or damaged growth and remove. Continue to cut away any twiggy growth to reduce the clutter.
Many garden manuals talk about pruning the centre of the plant, opening up the area and letting in sunlight and increasing air movement to reduce disease. This is great if you live in an overcast and damp area, but for most Australian gardeners, our blistering hot summers have a tendency to burn exposed rose stems pruned to an open vase shape, especially those at the base of plants. Rather than cutting out the centre completely, trim your rose so it will shade the graft.
The harder you prune your roses, the stronger, but less numbered, the new spring canes will be. This is fine if you intend to exhibit quality blooms on the show bench, but if you live in a high wind zone this strong growth will simply be blown over and snapped. The lighter you prune, the more buds you leave on the bush. The subsequent growth is more evenly spread and produces more flowers.
Climbing roses won’t need the hard pruning of a bush rose. Reducing these by no more than one third will ensure plenty of spring blooms. Trim the ends of any canes and tie them to the climbing frame. The more horizontal the stems can be tied, the more flowers will be produced. Don’t be afraid to cut off any strong canes you can’t tie; the energy they would have used will be taken up by the growth you leave. Again, remove old or damaged stems and attempt to spread the remaining ones evenly on your frame. Tie rather than thread any stems, particularly with lattice, which tends to split once a rose cane grows and thickens.
Ready for spring
If it looks like a pruned rose, it is a pruned rose. No two people prune the same – a comforting thought for those embarking on their first pruning expedition. While your attempts to cut back your roses may look a little amateur, be ready for a huge surprise in spring, when all the buds burst and your once barren bush miraculously transforms into a radiant display of colour.
Disease and insects can find ready homes in the nooks and crannies of the rose bark. Sitting quietly over winter, these ‘passengers’ can quickly multiply and take hold in the spring. An application of lime sulphur or copper oxy-chloride mixed with horticultural oil (such as white oil or pest oil) after pruning helps reduce their numbers and give your rose a healthy start.
Tips on maintaining your shears
It is vital to ensure your pruning shears are clean and sharp to avoid causing damage and disease.
1. Wash your shears with warm water to remove any grime. Dry them thoroughly. If rust has developed, use some steel wool to carefully polish it away.
2. Sharpen your garden shears using a hand file, working your way from the base to the tip. Ensure you keep with the existing bevel.
3. Apply a liberal coat of oil to your newly cleaned and sharpened pruning shears. This helps your pruners open and close easier.
Feature image: Roses like the Forget-Me-Not will bloom in just a few months time.
About the Author – Kim Syrus
Kim is the Executive Producer and Presenter on South Australia’s very own garden show In the Garden and has presented on Channel 9’s The Garden Gurus and The Gurus Explore.
A qualified horticulturist, Kim is one of the country’s most respected rose experts and Master Agent for the world-famous rose breeder Meilland International.