PORTLAND ROSE SOCIETY’S SPRING ROSE PRUNING GUIDE 2/19
As Spring progresses, gardeners begin to get anxious, particularly the rose gardener who wants to get out and prune the roses. Pruning roses is really a rather simple process, but a process which is hard to put into words. Every experienced rose grower will describe the technique slightly differently and probably will do it slightly differently. One important fact to remember is that no matter how you prune, unless you cut the rose off below the ground line, it will survive and bloom. A total lack of pruning will yield poorer results than any amount of over pruning you may do. So prune with confidence and the results will be good. A fact to remember is that we prune rose bushes for us, not for the rose. The rose will continue to thrive even if it has no pruning done to it, but it will not be as beautiful. To learn more about pruning roses, attend one of the pruning demonstrations presented by the PRS where you can ask specific questions, (the schedule of pruning demonstrations is in the PRS calendar), but for those who cannot attend, the following information should suffice as a guide to pruning roses competently and with confidence.
Identifying The Strongest Healthiest Canes
In studying the bottom of the bush, identify the youngest and strongest canes. These can be identified by their color, texture and size. Young canes, one or two years old, are usually green in color and have a relatively smooth outer surface. As canes age they will usually become darker or grey-brown in color as it develops a thicker bark. Aging canes also become rough in texture due to the cracking and peeling of the outer bark. With hybrid tea roses, canes which are easily identified as being old, are usually not very productive and should be entirely removed by cutting them off at the bud union (their origin) using loppers or a pruning saw. (See the darkened cane in the illustration to the right.) A non-productive older cane can be identified by looking at last year’s growth emanating from it. If all of the growth coming from an old cane is small and twiggy it is a sign that this is a cane that should be removed because it is no longer able to produce vigorous new growth and flowers. An old cane that has large healthy looking secondary canes coming from it is usually still productive and should be saved. If a cane is to be removed cut it off as close to the bud union as possible. Stumps of canes left protruding from the bud union after pruning are unattractive. If stumps are left sticking up they will eventually be consumed by fungi and will rot away. Since gardening is about beauty, try to remove old canes during pruning, the result is more pleasing than rotting stumps.
Opening Up The Center of The Rose Bush
Next, remove any of the younger canes which cross the middle of the bush. These canes should either be removed entirely back to the bud union, or back to the major cane from which they originated. Growth from crossing canes will become intertwined with other new growth with the net result being fewer quality flowers. Then remove canes which are crowded close to each other, usually leaving the larger one of each crowded pair. Finally, if there is any twiggy growth remaining anywhere on the bush, remove it back to its point of origin. (All of the dark colored areas on the bush in the illustration would be removed to achieve the desired effect.)
Pruned In A Vase Like Shape Open In Center
When the pruning is finished, the ideal rose bush will have only sturdy, healthy canes radiating from the bud union. In reality, this ideal is rarely achieved. Most bushes do not have enough canes growing in just the right directions to be ideal. If the bush has only 2, 3 or 4 canes, it would be best to allow them all to remain, unless one of them is truly a nonproductive old cane. If the rose has 5 to 7 or more canes, you can then begin making decisions about which ones to remove to achieve a pleasing balance. For most rose bushes, an outcome similar to the diagram below would be desirable.
Ideal Rose Bush With Health Canes
Maintaining a Disease Free Rose Bed
Also at this time, if there are still old leaves clinging to any of the canes, which is not likely, remove them because old leaves which have over-wintered may be disease carriers. These leaves should come off easily with a slight pull. Finally, spray the newly pruned bushes with a summer use fungicide. Do not apply any dormant sprays after pruning. The most common dormant sprays contain chemicals at concentrations that may damage the young buds that have already begun to grow. Many of this year’s disease problems are initiated when the buds first begin to grow, which they are probably already doing. Fungus spores which often over-winter on the canes and under the vegetative bud scales which cover the dormant buds can infect the bush as the buds begin to break, unless a preventative fungicidal spray is used. Spraying with fungicides should be repeated at 10 day to two week intervals during wet or damp weather to help maintain disease free bushes.
Clean Out Garden Debris
How low should hybrid tea roses be pruned? Again, every experienced rose grower will probably give a slightly different answer.
Three Categories Of Pruning
There are basically three general categories recognized for finished pruning height. The first is referred to as “hard pruning”. The illustrations at the right depict an average rose bush before pruning and after it has been “hard” pruned. When doing a hard pruning, the canes are cut back to a length such that there are only three or four buds on each of three to five canes. This will result in leaving only very sturdy canes about 5-12 inches long. Hard pruning is sometimes recommended for newly planted roses and is often used by exhibitors to promote the growth of exhibition quality blooms. The logic behind this is that the new canes which will grow from the old canes can be no larger than the ones from which they originated. So, if the new canes grow from very large canes, there is a good possibility that they will be large too. These larger flowering canes often produce larger flowers. Overall the result from hard pruning is larger but fewer flowers on the bush.
The second category is “moderate pruning”. The illustration at the right depicts the same plant after a moderate pruning. In this method, the canes are cut back to about 12-18 inches. Weaker than average canes need to be reduced by more than this amount. This is the recommended pruning style for most HT’s and floribundas in home gardens. This method of pruning will result in a bush that will produce more flowers and a bigger plant during the current season, but these flowers may be slightly smaller and the canes a little smaller than if the rose was given a “hard pruning”.
The third category of spring pruning is “light pruning”. The illustration at the right depicts the same plant with light pruning. In light pruning, the canes are cut back so that about two-thirds of their length still remains when the job is finished. Light pruning is not generally recommended because it often results in overly tall, spindly bushes in our climate area. These bushes will bear blooms earlier in the year, but the blooms will often be of poor quality and without stems suitable for cutting. The stems that are produced may have insufficient size to hold up the flowers. Among the hybrid tea roses there seems to be at least one exception to moderate pruning being the best practice. Peace roses and their descendants seem to perform better if given a light pruning. However, it is still wise to remove all the little and twiggy growth.
Light Pruning & Climbers
The severity of pruning has less influence over the growth and flower production of the bush than we think, unless little to no pruning is done. When we have had severe winters in Portland, severe enough to have killed a majority of rose canes all the way to the bud union, (to the ground), we have had some of our best spring rose shows, indicating that the bushes have the ability to re-grow rapidly. When winters are mild to moderate, like the current winter has been (so far), many people are prompted to do only a light pruning on the roses since all of the canes are alive and sprouting. When pruning time approaches, there may already be a lot of leafy growth on the roses and this is very difficult for many novice rose growers, and others, to remove during the pruning process. These lightly pruned bushes will produce lots of growth from the ends of the relatively small canes. This new growth will tend to be small in diameter and much of it may be broken off by the spring rains or by the weight of developing flowers. So, do not be afraid that you will over prune. It is almost always true that pruning too hard will produce better results than pruning too little.
NOTE: During any pruning take note of the color of the cut surface of the cane. It should be almost white. If the cut surface of the cane (stem) is brown it indicates that the cane has been damaged by the winter, and you need to cut it again a little lower until you find undamaged cane. It takes time for freeze damage to develop so it is possible that some healthy looking canes will need to be pruned again later in the spring.
Climbers need to be pruned differently. If a climber is trained into a horizontal position, as illustrated in the diagram, the only pruning that should be done in the spring is to prune the laterals, the short upright shoots coming from the main canes. These laterals should be reduced in length by pruning such that only two or three bud eyes remain, which is usually about 2-4 inches. An alternate method is to completely remove the laterals. The rose will then produce new laterals from dormant eyes in the main cane. The areas of pruning are marked with slashes on the diagram. Also, any old canes that are detected as being unproductive (no vigorous growth being produced by them in the previous year) should be removed to ground level (the bud union). New canes should be trained by tying them into a horizontal position. Any additional pruning should be done only to shape the bush to fit the style that is desired and to keep it in bounds. Climbers are meant to be large so we leave a lot of healthy wood.
Miniature roses are pruned in much the same way as hybrid tea roses, just on a smaller scale. Prune healthy canes back to 4 to 8 inches long and remove all the twiggy growth. Miniatures are very vigorous and will respond well to severe pruning by producing a number of new basal breaks, new stems originating from below the ground. You can prune them by shearing them if you like.
Old Garden Roses | Bloom On Old Wood
At this time, OGR’s and other onetime bloomers should be only lightly pruned to shape and control their size and to remove old unproductive wood. More pruning can be done, but these rose types produce their blooms on old wood and removing additional wood now reduces this year’s blooms. Save any major pruning on these roses until the blooming cycle is completed.
English Roses | David Austin’s
The English (David Austin’s) roses may be pruned like hybrid teas, but using the light to moderate pruning methods. Most of the English roses bloom on new wood, so pruning is done to produce a healthy base that can accommodate the current year’s growth just like HT’s, floribundas etc. Basically, if they grow like a climber, prune them like a climber and if they grow like a hybrid tea rose, prune them like a hybrid tea. I
In summation for any rose plant – remove all parts of the bush that are too small or weak to hold up the growth anticipated for this year and leave as much strong wood as you want, the more you leave the bigger the bush will be and the more flowers you will get. Portland Rose Society
This PORTLAND ROSE SOCIETY GUIDE TO PRUNING ROSES was reprinted with permission from Rich Baer of the PORTLAND ROSE SOCIETY P.O. Box 515 Portland, OR 97207
If you are interested in more information about the PORTLAND ROSE SOCIETY please visit their website www.portlandrosesociety.org for a calendar of events, membership information, upcoming events and about products available for their fundraisers.