Gardeners have been warned that a common mistake when pruning roses this September could leave plants vulnerable to disease and frost damage. Simon from the Walking Talking Gardeners YouTube channel emphasises that pruning is not simply a matter of cutting away dead flowers.
He explains: "Unless you are growing a pretty good range of disease-resistant roses, then the roses that are in your garden are probably looking pretty crappy right now. With that in mind, you could be forgiven for thinking that now is a fantastic time to give your roses a remedial cut, but that would be wrong."
Different varieties of rose need pruning at different points in the year and call for slightly varied pruning methods. However, several tasks rose growers must complete before the month draws to a close include inspecting roses and carefully cutting away any dead or diseased stems, as well as watching out for crossing branches that could start to rub together.
Why crossing branches are a risk
Simon says: "any rubbing branches ...will damage the thin bark of the stem and that creates an open wound which is then an infection point for fungal diseases."
To safeguard roses against winter storms, it is worth trimming back the plant's height at the start of autumn. Cut taller stems down by roughly a foot, always pruning just above a leaf node to prevent further dieback. Ensure you are working with a quality, sharp pair of secateurs to achieve a clean, precise cut.
What to prune and when
Any spindly or weaker branches should be cut back over the coming week, along with any dead or fading blooms. The one exception, Simon notes, is if you would rather allow spent flowers to develop into rose hips, which provide a valuable source of food for birds and wildlife as autumn sets in.
Regardless of preference, Simon warns that time is of the essence. These cuts should be made "at your earliest convenience," he says, as doing so will encourage new growth. He explains: "You require the next few months for that woody growth to harden off prior to the winter. Otherwise, that new growth will be hit and killed off by the frost, wasting your plant's resources, weakening it and reducing your display next spring."
Sterilise secateurs to prevent infection spread
Whenever carrying out pruning, there is one crucial safety consideration to bear in mind. Simon points out that many rose varieties are an "absolute magnet" for infections. These can be fungal in nature, such as Powdery Mildew and Black Spot, or bacterial and viral pathogens including Crown Gall and Rose Mosaic Virus. They can spread rapidly between plants, so you should take particular care to sterilise your secateurs after pruning any diseased or damaged growth.
Simon advises: "Either sterilise them over a naked flame or get yourself some rubbing alcohol. Wipe that on the blades. Leave it on for 10 minutes or so before wiping off and then rinsing." Should you discover any infected stems, do not simply toss them onto the compost heap after pruning - the pathogens could survive the heat of decomposition and find their way back into your flower-beds the following year.
When pruning, always cut just above a node - one of the small raised bumps where a leaf meets the stem: "Always have a slanted cut, so rain doesn't sit on the surface increasing the risk of fungal infections."
Pruning rules depend on rose variety
The most crucial question is when to prune, which depends largely on which variety of rose you are dealing with. Roses generally fall into four principal categories: rambling, climbing and shrub varieties, alongside hybrid tea and floribunda types.
Shrub roses, which produce blooms on the previous season's wood, have surged in popularity recently owing to their disease resistance and minimal upkeep. Now, as summer draws to a close, is the perfect moment to give them a tidy up. The ideal time to prune a rambling rose is straight after it has finished flowering. Climbing roses, on the other hand, flower on new season's wood, so experts broadly advise holding off from trimming them until November, or alternatively leaving them until March.
If you are unsure which variety you have, a handy rule of thumb helps tell them apart. Climbing roses tend to bloom repeatedly, producing larger flowers on firm, upright stems, whereas rambling roses are vigorous, flexible growers that typically put on one spectacular display of smaller, clustered blooms around June. For those with hybrid tea or floribunda roses, the optimal time to attend to these plants won't come around until next March.
