Pruning Roses in Northern Colorado
By Stan V. Griep
Colorado Native Rosarian
Over 40 years of Rose Growing Experience
I am what is known as a “Spring Pruner” when it comes to pruning roses. Instead of pruning the roses way down in the fall after they have gone dormant, I like to wait until early spring when I see the leaf buds starting to form up well. My taller rose bushes do get a pruning down to about half their height once they have gone dormant in the fall. The fall pruning I do is to help prevent damage to the overall bush from winter winds and heavy snows. The winds and heavy snows can break over long rose canes causing great damage to the overall bush, sometimes to the bushes nearby as well.
I do the standard “by the book” type pruning with my hybrid tea roses for the most part. I select an outward facing leaf bud eye and prune on an angle away from the bud eye 3/16 to ¼ inch above the bud eye. That cut is then sealed with white glue that is not water-soluble. There are times when a particular cane may be at a fairly harsh angle from the center of the bush. In such cases I will select an inward facing bud eye and prune there. By pruning at the inward facing bud eye the new cane that grows forth will come back into alignment with the rosebush for a better looking overall bush. You need to look at each rose bush kind of like an artist looks at a blank canvas. Picture how you want the rose to be shaped. Then prune the bush accordingly. I prune all of my rosebushes with the “blank canvas” approach. A blooming rose bush is truly beautiful without a doubt. However a rosebush with wonderful overall form and loaded with beautiful blooms is indeed a work of art.
Here in Colorado, even with mounding the rose for winter protection, we can get some very significant cane dieback on our roses. There have been many times when the canes that are left on the roses after spring pruning are only 1 ½ to 2 inches long. Pruning down that far is required to get to a good white center of cane pith and a healthy bud eye. Such harsh pruning can make it extremely tough on the “blank canvas” approach yet it is still possible. You need to focus on where the bud eye is located and envision where the particular cane will be as it grows. You do not want canes to cross over one another creating a jumbled mess in the bush where insects or funguses can cause problems. Yet you do want a nicely shaped bush with lush foliage to properly display the beauty of the blooms.
The floribunda and grandifloras roses get pruned in much the same way as the hybrid teas except that I do not worry much about finding outward facing bud eyes. I still keep in mind where a cane will go as it grows so as to avoid the crossing canes. However with the floribundas and grandifloras I like a full looking rosebush that will fully present the beauty of the clusters of blooms against their rich foliage.
In my opinion, when making the pruning cut, it is better to have a flatter cut than a cut that is too steep. The angle of the cut is somewhat important to allow moisture runoff and such, yet it is not a crucial error if the cut is considerably more flat than a 45-degree angle.
The cut end of the cane can still be sealed and the new growth that forms from the bud eye still has a good base for support. Whereas a pruning cut that is too steep exposes more of the center pith than should be exposed and provides an extremely weak foundation point for the new growth. The steep cuts are also extremely hard to get a good seal on and will tend to allow easier pest invasion.
My mini roses are truly easy to prune as I simply prune away the winterkilled portions of their canes while forming up the bush. If the centers of the mini roses are too full I simply prune a couple of small canes out and the bush is done. In no time at all the new growth will have the overall form of the bush right where I want it.
When deadheading my roses I prune back to the first five-leaf junction with the main rose cane, as long as the cane in that area is sturdy and at least 3/16 of an inch in diameter. Too small of a cane at the area of new growth generation and future rose blooms will cause a sagging effect if the roses blooms are large blooms. In cases where the cane is too thin at the first five-leaf junction, I will prune down to the next junction where the cane is the desired size. The mini roses are an exception to this deadheading/pruning. When pruning my mini roses I simply prune off the bloom down to where the stem meets with the first group of leaves with no apparent effect upon the size or support of the rose blooms to follow.
Some other very important things to remember when pruning are:
1. Always seal the ends of the pruned canes that are 3/16 of an inch or larger in diameter with white glue or tree wound tar type sealer. This will help keep the cane borers away.
2. Always wipe down the pruners cutting blades with a Clorox or Lysol disinfectant wipe or dip the cutting blades into some form of disinfectant solution after pruning each bush. In some cases it may be necessary to wipe or dip them after each cut, such as when pruning out an infected or diseased cane. You do not want to spread the disease from an infected cane or bush to other canes or other rosebushes.
3. When finished pruning for the day and after disinfecting your pruners, spray the blades with some silicone lubricant spray or other protective lubricant. It does not take long for rust to form and damage your pruners. Plus the lubricant helps keep the pruners working well and not so hard on arthritic hands.