Daniel Gill, Merrill, Thomas A. | 7/28/2007 2:26:23 AM
By Dan Gill
LSU AgCenter Horticulturist
In Louisiana our ever-blooming roses fortunately provide us with two really great seasons of bloom, and now is the time to prune in preparation for one of those seasons.
The first outstanding season of blooming occurs in spring and early summer – from April to early June. Roses continue to bloom through the summer, but the flowers produced in mid- to late summer generally don’t have the quality of the flowers produced earlier.
The second outstanding rose blooming period will occur in October and November when mild weather conditions will once again be ideal for quality flowers.
Although we should have pruned our rose bushes back in early spring, they have been growing since then, and many may look overgrown, leggy and less attractive now. That’s particularly true with the popular hybrid teas and grandifloras.
So a second, less severe pruning is recommended in late August or early September to get rose bushes in shape for the fall blooming season.
The tools you will need include a sharp bypass hand pruner and a pair of leather gloves. You might also need bypass loppers if you have to cut woody canes larger than one-half inch in diameter. Proper tools make the job easier, and you’ll be less likely to damage your rose bushes or scratch your hands on the thorns.
Examine the bushes carefully. Look for dead canes and weak growth. Check the height and overall shape of the bush. Is it overgrown and leggy? Is the present shape acceptable, or does it need reshaping? The following recommendations are primarily for hybrid tea and grandiflora roses.
First, all the dead growth should be removed. Make your cuts well into the healthy part of the canes just above a leaf or dormant bud – or remove the dead cane entirely back to its point of origin. You may need your loppers for this job.
Next, remove weak, spindly canes the diameter of a pencil or less, particularly those growing in the interior of the plant. Cut them off at their point of origin, making sure you do not leave a stub. If you see any sprouts originating from the root stock (below the large, knobby graft union), cut them off, too. Do not remove any strong new shoots growing from the graft union, however.
The major part of the pruning involves shortening the remaining vigorous canes. This will produce a fuller, more attractive bush with larger, better quality flowers in October. This pruning needs to be done even if there are flowers on the bush now. (Be brave!) When you are finished, use the cut flowers in arrangements inside, and they won’t go to waste.
Cut the canes back to about 30 inches from the ground. Ideally, try to make each cut just above a bud that faces outward (away from the inside of the bush). The cuts should be made about one-fourth inch above the bud at a slight angle slanting away from the bud. Don’t leave a large stub sticking up above the bud or you will encourage stem rot, and don’t cut too close to the bud or you will kill it.
Clean up and dispose of all leaves and prunings from the area. Then fertilize the roses to encourage vigorous new growth. Use your favorite rose fertilizer following label directions or use a general-purpose fertilizer appropriate for your area.
Ever-blooming old garden roses, shrub roses, landscape roses and other groups also may be pruned now, but the pruning required generally is less severe and is done mostly to shape the bush or to control the size of more vigorous cultivars. Use your best judgment when it comes to pruning these roses.
With old garden roses you really have to look at the situation and how the rose is growing. Then prune accordingly based on how you want the rose to look.
I even know a few gardeners who prune their bushier roses with hedge trimmers. This is a particularly effective technique if you have planted a long hedge of roses that would take a long time to prune with hand pruners. On the other hand, this clipped appearance may not be suitable for roses growing in garden beds.
Some roses – including many climbing roses, ramblers and old roses – only bloom once in spring and early summer. They should not be pruned back now, since they will produce flowers next year on the growth they made this summer. Cutting them back now or anytime before they bloom next year will reduce the number of flowers they produce.
Pruning is a job that many gardeners approach with apprehension. There is always a fear that if it’s not done correctly dire things may happen to a plant. With some exceptions, pruning shrubs is more like getting a haircut. Even a really bad haircut eventually will grow out and look better.
Carefully consider what you are trying to accomplish before you start pruning and have clear goals and objectives. But the only way to really get comfortable and confident about pruning is to just to do it and watch what happens. Roses are very forgiving about how they are pruned, so they make great plants to build up your confidence.
Get It Growing is a weekly feature on home lawn and garden topics prepared by experts in the LSU AgCenter. For more information on such topics, contact your parish LSU AgCenter Extension office or visit our Web site at www.lsuagcenter.com. A wide range of publications and a variety of other resources are available.