Pruning our Desert Roses
By Hal Reynolds Vice President, Desert Rose Society, ARS Consulting Rosarian
The best way to start a discussion on pruning is to explain why we prune. Roses are willing and eager to grow for you, but they need a few things for them to do their best. They need water, fertilizer, sunshine, decent soil, and PRUNING. Cutting the rose plant back promotes new, vigorous growth that will produce the greatest number and best quality blooms. Pruning promotes the growth of basal breaks (new canes), which are always a delight to the rosarian’s heart. After all, it is the roses we want, so why not give our plants the best chance to produce them for us? In the desert we generally prune most roses twice a year: a severe cut back in January or February and a moderate pruning in September. The winter pruning involves cutting the plants back hard as well as removing all leaves, which brings on a showy spring bloom.
A benefit of the rather drastic pruning we do in the spring is that it gives us access to the ground around our plants allowing weeding, the application of mulch, and general clean-up. Sanitation consists of removing all remaining leaves from the plant after pruning and raking up all fallen debris around the plants. This cleanup reduces the chance of fungal infestations caused by debris carried forward from last year to infect this year’s growth. Nobody likes to live in a dirty place, not even roses.
How far down to prune? First you need to know what a growth node is. There is a growth node wherever there has been a leaf on a rose stem or a branch. Once the leaf is off of a rose plant, you will notice a little crescent mark on the stem. In the middle of the crescent and just above it is a little lump. That lump is a growth node. That node is capable of becoming an entire branch of roses or an entire rose bush. This is true of all of the nodes. So when we talk about pruning and say to cut ½ to ¾ inch above a growth node, this little lump in the
middle of the crescent is what we are referring to.
You will need a few tools to accomplish your pruning job. First and most important is a sharp pair of pruning shears. Always use pruning shears with bypass blades, that is, with action like a pair of scissors, not shears that cut by pinching down on a flat surface. Avoid these anvil type pruning shears that smash the stems. You will need a pair of loppers for the large, thick branches and occasionally a pruning saw for the super large cuts. It will not take you long to learn that thick leather gloves with long gauntlets are your best friends when pruning roses. And it is always a good idea to keep your tetanus shot up to date when dealing with things that might stick you.
Most roses you will be dealing with are grafted roses. Roses are grafted onto rootstocks in order to provide the plant with a root system superior to their own natural roots and to speed up the process of producing mature rose plants. The fact that roses can be produced faster benefits the grower but also the customer because it keeps the prices more reasonable. On a grafted rose there will be a trunk coming up from the ground and a little distance up from the soil, there will be a large lump from which come all the branches of the plant. That lump is the plant’s graft union, where the root and the top of the plant are joined. Any growth that comes from below that is not the rose you bought; it is the root stock. If the root stock starts to put out shoots, you must remove them as close to their source as possible. If the rootstock is left on the plant, it will dominate and destroy the variety you thought you purchased. If you do not remove these suckers, you will usually end up with an ugly little red rose named Dr. Huey. Dr. Huey produces great roots and ugly roses.
Pruning Hybrid Teas:
Rising from the graft of a rose there are usually several branches coming up from above the graft. They ideally would be arranged in an open vase formation, in other words, a cone shape with an open center. If canes cross and touch each other, one of them should be removed, preferably the weaker of the two. Remove any broken or damaged growth by making a clean cut below the damage. Now comes the part about how to cut back and how that relates to the growth nodes. Generally, leave six to eight growth nodes on each branch. This height will vary a great deal depending on the growth habit of the variety. Some have much longer internodes than others. Cut to an outside growth node. This means cut about ½ to ¾ inch above a growth node facing out from the center of the plant. Some say that this cut should be on an angle to help water drain off the stub. I personally do not worry about whether the cut is angled or not. Some people feel that all cuts should be sealed to prevent cane borers from getting into the plant. They spread something like Elmer’s glue or pruning sealer on each cut. I do not do this and do not find I have much, if any, problem with cane borers. Angled cut or not, sealer or not, the choice is yours. On the rare chance you have too many canes coming up from the base, you can completely remove some, preferably the oldest, smallest, and weakest. I, however, never seem to have too many canes.
Often you will see small limbs an inch or two long that come out from main stems. They have a few small leaves and usually come to a point. These little shoots will never grow into any thing greater than they are so remove them. On old roses that have been in the ground for many years, you may notice old, loose, craggy bark around the bud graft area of the rose. It is a good idea to use a wire brush or your hands to remove as much as will come off relatively easily. Removing this old growth opens the way for new shoots to emerge from the graft. Keep in mind when pruning and deadheading that any growth coming from a branch will never exceed the size of the branch it is coming from. In other words, a really small, mature limb, smaller than a pencil, is not of much use.
You will need to remember that floribundas are generally smaller plants than hybrid teas, produce smaller flowers, and often present their blooms in sprays or clusters. The pruning basics are pretty much the same as for hybrid teas. A floribunda may have more and smaller limbs coming from the base and on floribundas, that is fine. After all, on these plants you are going for the number of blooms rather than large blooms.
Pruning Minifloras and Miniatures:
The miniflora is simply treated as a smaller form of the hybrid tea. Prune them as you would a hybrid tea, just on a smaller scale. The miniatures can be pruned as you would prune a hybrid tea but it is time consuming on those little guys. Some people prefer to just give the miniatures a haircut. They just cut the plant back by shortening all the growth. I must say that although the little ones take some time to prune correctly, I found much better results when I took the time to give them a proper pruning. Virtually all miniatures and most mini-floras are usually growing on their own roots, and not grafted plants. Important note: If a rose is growing on its own roots, any growth coming from the ground next to the plant is not a sucker; it is another shoot of the plant.
Pruning Climbing Roses:
The first thing you need to know is that climbing roses are not really climbers. They are just roses with a hormone problem. That is to say, they grow too tall and lanky. If you think about it: they do not have tendrils; they do not wind around support structures on their own; they do not have roots or sucker-like sticky appendages that help them hang on. If you see a rose “climbing” a trellis, wall, or arbor, you can jolly well bet some gardener has given it a helping hand. The second thing to learn about “climbing” roses is that horizontal is better than vertical. When growing horizontally, a rose will produce more roses than when it is growing straight up. When you purchase a good climbing rose, the tag should give you an indication of the length it can grow to. We prune to promote blooming and to control size, as some varieties can grow to 40 feet. They have been known to take over entire neighborhoods and kidnap small pets, children, and tool sheds.
When pruning climbers, you need to remember that there are two kinds of limbs: main canes and laterals. Main canes are those canes coming from the very base of the plant and are really long. Laterals are those smaller branches coming off the main cane and growing perpendicular to it. The laterals are where the roses will grow. Keep in mind that these instructions are for the climbers we refer to as large-flowered climbers or LCl roses. If you are dealing with a rambler, pillar, or Old Garden rose, different rules may apply.
After planting a climbing rose, you do not want to prune it for the first two or three years. You want that rose to get established and produce some nice long canes. To become more familiar with your climber in the first couple years, you should train it by tying it in place with stretch tape. This is when you establish the framework for future blooms. Remember, horizontal is better than vertical. You can train a rose on a 45° angle, then back at a 90° angle in the other direction, and back again if you wish to cover an area like a trellis or wall. If you let a climber go straight up, it will tend to bloom only at the top of the plant where the blooms are less likely to be enjoyed.
If your main canes become too long for the space you have allotted, you can, of course, cut them back to the desired length. When a main cane stops growing and is not as long as you want it to be, go back down the cane to a strong, promising lateral and cut the main back to just beyond that strong lateral. Treat that lateral as the continuation of the main cane.
The actual pruning of the climber involves cleaning out any of the oldest, nonproductive canes when needed and any of the worthless, twiggy growth that may be coming from the base and adjusting the length of the main canes. This main pruning is done in January here in the desert. The important part of the pruning is to cut back the laterals: those smaller secondary branches growing perpendicular to the main canes. Prune them back to 6 to 10 inches. This will promote new growth and is where your roses will develop. As your season goes on, you will be cutting back laterals every time you pick a rose or deadhead a rose, thus promoting repeat bloom on the roses that can repeat.
Warning! Warning! Pruning of Old Garden Roses:
You do not prune Old Garden Roses as you do other garden roses. A majority of Old Garden Roses and Species roses have only a single bloom time. They do not repeat bloom like modern roses. Generally once blooming roses, if they are pruned back at all, are pruned right after they bloom. Most often they are pruned to keep them under control, or to shape the plant. For the rest of the Old Garden Roses, the pruning time and method will vary depending on the type of Old Garden Rose. They usually grow on their own roots and are not grafted. Again, if there is growth coming from the base of the plant of an own root rose, it is not a sucker -- it is a shoot of the plant.
Fall Rose Pruning:
I also do a fall pruning in which I cut the plants back by about 1/3 as soon as the day temperatures stay below 100° and the night temperatures stay below 80°, about September 15th. I basically remove any growth smaller than a pencil and prune back below where the main branches sprouted the stems of previous blooms. I prune to an outside growth node just as I do in the spring. Others feel that they only need to do a deadheading type of maintenance on an ongoing basis through the year. In the fall you can feed as soon as you prune.
In the process of pruning, you have to apply common sense and be flexible. Too often the ideal situation will not exist. The growth node will not be where you would like it to be. Or the branches are not arranged as you would have them be. You just have to adapt to the plant as it is, take your best guess, and proceed gaily forward. Just remember, with roses (except for Old Garden Roses as noted above), to prune is better than to not prune. It may seem you are destroying your beautiful plants but you are not. They will love you for it and provide you with beautiful and colorful rewards to the senses.