Give your shrub roses a winter maintenance pruning.

01/16/2002
Give your shrub roses a winter maintenance pruning.

Dare I say it? Pruning is always a thorny topic in rose circles. But in twenty-five years of growing roses, I've learned that what I call "winter maintenance" pruning is nearly indispensable to the health and long life of shrub and climbing roses. The details of pruning of tea roses, on the other hand, I'll leave to the advice of other experts, as modern hybrid teas interest me not at all.

But I'm impassioned by the huge variety of roses that are commonly and roughly grouped as "shrubs", including all the old roses as well as many new "landscape" roses and a welter of others. My point here is not to go into the fine points of rose classification, but merely to encourage you and show you how to give your shrub roses a formative winter pruning that will promote the health of your roses without the use of chemical fungicides, increase their vigor and long life, and ensure the proliferation of lots of flowering--as opposed to senescent or merely vegetative--wood.

Every cane produced by your shrub rose goes through a natural cycle of vegetative growth, production of vigorously flowering wood, senescence accompanied by a decline in flowering, and death. In winter pruning, your job is simply to accelerate this process to your advantage and to create a greater abundance of flowering--as opposed to vegetative (leaves only) and senescent--wood.

This sort of pruning absolutely has to be done while the plant is dormant, for the simple reason that you can't see what's going on when the shrub is covered with foliage. But in winter, your rose stands naked before you, with all its blemishes apparent.

A shrub rose that has been left unpruned for several years--or never pruned at all--will present you with an intimidating tangle of growth, similar to or worse than the 'Cornelia' hybrid musk shrubs in the photo at left. At first glance, your natural reaction--and mine as well--is "Where in the world do I begin?" The welter of canes and twigs looks simply unintelligible.
But like all daunting tasks, this one can be conquered by remaining calm and proceeding in logical steps.

First though, take a look at yourself. Are you dressed warmly, in layers that you can add or take off at will? This is the time of year when the sun can appear to flatter you with a moment of warmth, or suddenly vanish beneath a wall of sullen clouds, leaving you in the grip of bone-chilling cold. It's important to be as comfortable as possible during the task of rose pruning. Make sure you're wearing thorn-resistant, long-cuffed gloves to protect your hands.

Second, arm yourself both with a good pair of pruning shears, as well as a pair of loppers for heavier cuts. Occasionally, a small pruning saw may also come in handy.

Okay, now that you're properly dressed and equipped, take another look at those god-awful roses. The first step is to identify and eliminate all dead wood. Canes that have been dead for more than a year turn silver gray and snap easily. Cut them off at ground level, leaving no stump. Dead lateral branches or branch tips--more recently deceased--may simply look blackened. To check whether a branch is living or dead, simply scratch the bark of the rose with a fingernail or knife. Dead wood has blackened bark that slips off easily, and the tissue beneath the bark or epidermis is dark brown to black as well. Live wood, on the other hand, has green, turgid epidermis, and the tissue beneath is white to pale greenish beige. Cut dead laterals off snugly at the point where they emerge from the mother cane. Cut dead terminals--or tips--at least an inch below the end of dead tissue, well down into live wood.

Now a word about the pruning cuts themselves. All cuts should be made at a 45-degree angle, beginning just above and ending just below an outward-facing bud. Why? Well, the angle allows the cut to shed water, minimizing chances of rot and promoting healing, or the formation of callus. Cutting by an outward-facing bud will cause new growth to be directed to the exterior of the shrub. This is desirable, because canes or laterals heading to the interior decrease air circulation through the shrub, which promotes disease. Inward-growing shoots also tend to cross other canes, rubbing against them and causing wounds which allow disease organisms to enter. Finally, you make all your cuts just by a bud--and not in the middle of the internode, or space between buds, because all the wood between where you cut and the bud below will die, again promoting disease if left in place.

This brings me to a second pruning step. If the rose has been badly pruned in the past, there may be may such "stumps" of dead tissue above a branch point. Cut these off snugly at a 45-degree angle next to the live branch.

Already your rose is starting to look a little better. But now come the more bewildering pruning decisions. The next step is to remove at their origin or branching point all laterals which grow toward the interior of the shrub, instead of heading in an outward direction. This opens up the shrub to good air circulation, minimizing disease problems. And very few of those introvert twigs ever produce flowers anyway.

Next, look for canes or laterals that are rubbing against each other. Remove the less important or less vigorous of these to prevent the formation of wounds which promote diseases such as canker. After that, remove all spindly canes emerging at ground level that are thinner than a pencil, as well as all very thin twiggy growth emerging from the major canes. The French call this kind of puny growth brindelles. So get rid of them.

Once these steps are done, your rose is looking a lot more civilized. Now come the real judgment calls. Your rose may present you with confusing scenes such the one at left. Many shrub roses--hybrid musks in particular--have a habit of producing as many as three canes at a single joint, thus violating the pruner's rule of thumb that only one branch should be allowed at any given bud point. The reason is that if more than one branch emerges from a bud, none of them will be vigorous enough to produce many flowers.

Choosing which of these branches to eliminate, such as in the congested joint pictured, can take some practice. First, if one of them is distinctly puny, take it out snugly at its origin. Next, look for the older, more senescent branch, identified by its darker brown--rather than green--bark, and by the weak, erratically twigged growth it terminates in. This sort of branch or cane is on its last legs; get rid of it. This leaves you with the most vigorous branch which will now grow unimpeded and vigorously to produce plenty of flower buds.


When faced with a difficult task, I always like to save the easiest part for last, when I'm too worn out to face any more hard work. In rose pruning, the easy stuff consists of removing last year's flowering terminals to the second bud below (or lower, if necessary to find an outward-facing bud); and of "heading back" vigorous vertical-growing shoots. This forces them to branch out and form flowering wood instead of just shooting skyward with one long leafy spear. Now your roses should resemble the ones in the photo below right.

Always keep in mind that branches approaching the horizontal produce the most flower buds. This is for the simple reason that as long as the rose's sap can flow skyward unimpeded, the hormonal message to the rose is to keep on growing vegetatively (without flowers). But the minute that flow of sap is stopped (by a pruning cut) or braked (by training or tying down a cane to an arched position), all the vegetative buds are transformed into flower buds. And flowers are what we're after here.

Essentially the same principals apply to pruning climbing roses, but the process is complicated by the need to train and tie down the canes. Plus there's the fact that much of your work may take place on a ladder 20 feet off the ground, which is how Denis took this photo of me from the second story window! More on that in another article.

A couple of words of caution. Never prune when the temperature is below freezing. Cutting frozen wood--whether on a rose or any other shrub or tree--causes it to burst at the point of the cut, creating cracks in the remaining wood which never heal properly. Second, realize that on a once-flowering rose, you are removing flower buds with your winter pruning cuts, as the flower buds are already in place, just waiting for spring to arrive. So on once-bloomers, keep your cuts to the strictly structural, and save "heading" cuts, which remove branch terminals, until just after the rose finishes blooming (usually early July).

I hope that winter pruning your roses isn't as exhausting a task as it was for me the first time I attacked the neglected roses at our house in Normandy. I felt--and looked--as if I had just completed a week of guerilla warfare (see photo at left--gee, I should have made that photo smaller!). But my well-earned reward the following spring was the bounty of flowers pictured at the head of the article. Much like childbirth, it was awful while it was happening, but in hindsight, the joyous result happily obliterates the painful memories.

For a much more in-depth look at pruning and all other aspects of rose growing, see my upcoming book, due out from Rodale Press in May, Growing Roses Organically.

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