Richard Bogren, Gill, Daniel J.
For Release On Or After 01/28 /11
By Dan Gill
LSU AgCenter Horticulturist
It would be hard to dispute that the most popular summer-flowering shrub is the rose. Most roses need at least some annual pruning to maintain an attractive shape, remove dead wood and encourage vigorous growth and blooming. This is generally done from the last week of January in south Louisiana through mid-February in north Louisiana.
Pruning back roses takes some getting used to. Many new gardeners have a hard time getting up the nerve to cut their bushes back. If you don’t, however, the result will be tall, rangy, overgrown bushes that will not be nearly as attractive. It is far easier for you and healthier for the rose bush if you do this pruning regularly. Don’t forget that we also do a second, but not as severe, pruning in late summer around late August.
Hybrid Tea and Grandiflora Roses
Use sharp, bypass-type hand pruners, which make clean cuts and minimize damage to the stems. Wear a pair of sturdy, leather gloves and long sleeves because no matter how careful you are, thorny roses can painfully puncture or scratch your hands and arms. Should you need to cut canes larger than one-half inch in diameter, you should use loppers.
First, prune out all diseased or dead canes, cutting them back to their point of origin. Weak, spindly canes the diameter of a pencil or less also should be removed the same way. A good rose bush should have four to eight strong, healthy canes the diameter of your finger or larger after this first step.
Cut back the remaining canes to about 24 inches from ground level. Newly purchased roses have already been pruned and no further pruning is required. When you prune back a cane, make the cut about one-quarter inch above a dormant bud or newly sprouted side shoot. Try to cut back to buds that face outward, away from the center of the bush. The new shoot produced by the bud will grow outward, opening up the bush for light, air and orderly growth. This may seem picky, but this really does make a difference.
Pruning other types of roses
Old everblooming garden roses, landscape roses (such as the popular KnockOut roses), floribunda roses and polyantha roses also may also pruned now. These roses, in general, have more pleasing shapes without severe pruning. They are only lightly shaped under most circumstances, unless you need to control their size.
You should still check for any dead wood and prune that out. Excessively long, vigorous shoots growing out of the bush should be headed back to within the outline of the bush to keep the shape attractive. Other than that, how far back you cut old garden roses depends on the situation, vigor of the bush and the desired size. It is typical to cut back old garden roses and landscape roses by about a third of their height.
Any roses that are not everblooming, including many climbing and rambling roses, such as Lady Banks, Dorothy Perkins and Blaze and some old garden varieties, should not be pruned now. These roses produce their flowers in one big flush during late spring and early summer on growth made the previous year, and then they’ll bear few or no flowers the rest of the year. If pruned back hard now, they’ll produce few, if any, flowers. If they need extensive pruning, it’s best done in midsummer after they have finished flowering.
In addition, these types of roses should not be pruned back hard each year like the modern bush roses. Pruning climbers and ramblers is largely determined by how large and on what structure they are being trained. Pruning, when done, is more selective and less extensive.
Most nurseries already have their rose bushes in stock, and now through March is a good time to plant. If you intend to plant bare-root roses, get them planted before the end of February. Bare-root rose bushes should be planted before they begin to sprout.
Early planting allows rose bushes to become established before they begin to bloom. This increases the number and quality of flowers, and the bush is better prepared to deal with summer heat when it arrives in May. Plant roses in a sunny, well-prepared bed that has excellent drainage. For more information on growing roses in Louisiana, the LSU AgCenter offers an informative publication that’s available to download online. You can find it here.
Now is also a good time to transplant roses from one location to another in the landscape. Cool weather reduces the stress of transplant shock brought on by damage to the roots when the plant is moved and increases your chances of success.
Take care to disturb the root system as little as possible when moving roses. Dig plants with a ball of soil around their root systems, getting as many of the roots as possible. If the soil falls away, don’t let the roots dry out. Moisten the roots and wrap them in plastic, a garbage bag or damp fabric, get the plants to their new location quickly and plant them immediately.
Make sure you plant transplants at their original growing depth, and water them thoroughly after planting to settle the plants in. Be sure to water regularly over the next few weeks and then during any dry periods over the next few months.Rick Bogren