Gardening with Jane McLeod: Preparing hardy roses for winter
September 15, 2013
Steamboat Springs — Preparing hardy roses for winter is not difficult. It mostly requires restraint. First and most importantly, put away the pruning shears. Additionally, reduce watering starting in September (avoiding drought in a dry fall) to eventually nothing.
Sound easy so far? Good, because that's about it.
As roses head into their autumn swan song, resist at all costs the temptation to deadhead (removing faded blooms to encourage new ones). Although roses certainly will bloom again without deadheading, they will bloom quicker if you do. At this point in its life cycle, the rose needs to finish its job by putting its energy into developing rose hips and going dormant rather than into new growth that will die at first frost.
Rose hips are those bright, reddish/orange berries appearing where a flower used to be. Inside are rose seeds and thus the end of the reproductive cycle of the rose. It is only when the rose sets hips that its seasonal job is done and it can go to sleep for a much-needed break.
When you trim a bloom (or stem), it is a signal to the rose that it hasn't finished its job, and consequently, it will produce another flower in the hope of it becoming a hip. To produce a flower, the rose pushes sap up into the outer and most tender branches, which can freeze if the temperature dips suddenly. This sap freezing process can blow the rose cell wall apart from within, damaging the rose.
If you aren't interfering, a rose instinctively sends the sap down to the roots where it is protected from such calamities. Also, as shorter daylight hours and falling temperatures trigger a rose to slowly go into dormancy, the cells that contain water thicken and reduce the amount of water within, converting it to a form that resists freezing.
The degree to which a rose can make this conversion defines its cold-hardiness, which is why I always recommend you buy Zone 2 or 3 hardies. Hardy roses are exactly that and can survive a freeze with some sap and water still in the canes. If their natural rhythms haven't been interfered with, they will approach their long winter slumber healthier and better prepared.
The no pruning dictum applies also to the rose canes unless they are dead, diseased or damaged. With an exceptionally long one that you fear will get whipped by winter winds, either secure it or cut it down a bit once the rose has gone dormant. If you are desperate to do something to justify earning the respect of your roses, it's always a good idea to add a couple of inches of compost to the garden in late fall, but that is all that is required for winter protection.
Hardy roses come with good winter survival skills, so sit back, watch the rose petals drift to the ground, and let your rose bush slow down to a rest and get ready for next year's spring spectacle.
Jane McLeod is a master gardener with the CSU Extension Routt County. Contact 970-879-0825 or firstname.lastname@example.org for more information.