It’s rose pruning time and we’ve found these helpful tips courtesy of the U of A Cooperative Extension and the Clemson Cooperative Extension publication, “Pruning Roses” by Karen Russ and Bob Polomski. Pruning roses keeps the plants healthy, promotes new growth, removes dead, broken or diseased canes, and/or trains the plant to a desired shape. It’s important to prune because it encourages flowering, either more blooms or larger blooms, and keeps modern rose varieties blooming repeatedly all summer long – even in our hot desert.
Southwest Gardener’s own rosarian, Bruce Solomon, is teaching a February class on all the particulars of growing roses in our dry, hot climate. Not only does Bruce have many years’ experience working in the nursery industry, he also holds a degree in landscape architecture. Bruce will teach you to be a successful rose gardener, from planting, fertilizing and nurturing your plants, to pest control and pruning.
Roses need different types and timing of pruning depending on their variety. Repeat blooming roses such as floribunda and hybrid tea roses need a heavy annual pruning that is done in late January in the desert, early spring in colder climates, just as the buds break dormancy. The best way to judge when to prune is to look at the buds; when they begin to swell, start pruning. Old-fashioned roses and climbers that bloom only once a year should be pruned immediately after flowering. Do not prune these types of roses heavily in the early spring since they bloom on wood from the previous year’s growth. Dead, diseased or damaged wood on any rose should be removed as soon as it is seen.
To prune you will need: sharp bypass hand pruners, loppers, and possibly a pruning saw for larger cuts. When pruning, keep the hand pruners and loppers in a coffee can filled with 70% isopropyl alcohol to minimize disease transmission. Sturdy gloves with long cuffs and a long-sleeved shirt will protect your hands and arms.
The main steps in pruning roses is the same for all rose types.
1. Remove all dead, damaged or weak stems leaving only the most vigorous, healthy canes.
2. Check to make sure the stems show no sign of discoloration. The center of the canes (rose stems) should be white and plump, not brown and withered. If they appear diseased, you will need to cut farther down into healthy wood. If no live buds remain, remove the entire cane.
3. Prune the bush to make it more open in the center. This will increase air circulation and help prevent diseases. Since rose bushes send out new growth from the bud just below a pruning cut, try to make pruning cuts above a leaf bud facing out from the center of the plant.
4. Make a cut 1/4 inch above the bud and angled at the same angle as the bud. Whenever two canes cross each other, one can be removed.
Deadheading is cutting off spent flowers. Old blooms left on the plant may begin to form hips (rose fruit). Hips are often very attractive and can be left on some roses for winter interest and bird food. Hybrid tea roses and other roses that can rebloom should not be allowed to form hips, so that the plant will put its energy into flowering. To deadhead, remove the flower by making a diagonal cut just above the next five or seven-leaf branch down on the stem. This should be above a strong bud that will produce a healthy cane. All pruning cuts on canes greater than the thickness of a pencil can be sealed with wood glue to prevent cane borers from entering.
Hybrid Teas, Floribundas and Grandifloras
Prune hard if you want large blooms suitable for cut flowers. This will produce fewer total blooms. Cut out all but three to five of the healthiest, most vigorous canes. Prune these canes down to 15 to 18 inches from ground level. Keep any weak, small or short stems pruned away. Generally with hybrid teas, any cane thinner than a pencil should be removed. In the late fall, prune roses back by about one-third of their height.
Old-fashioned rambling roses and one-time spring-blooming climbers produce best shoots growing off one-year-old wood, and they should not be pruned until after they flower. Cut away all weak or damaged stems and remove the oldest canes, leaving five to seven strong canes untouched. Remember that flowers are produced on stems at least one year old on most running or climbing roses. The stems that you leave will bear next year’s flowers. Climbers that bloom on the current season’s growth can be pruned more severely.
Old Garden Roses
Old roses do not need the hard pruning that is needed by many modern roses. Hard pruning can ruin their graceful shape and severely reduce their flowering. Preserve the informal habit of old garden roses by removing no more than one-third of each bush. Generally, remove only the oldest stems that are no longer productive. Most old garden roses bloom once in a season. Prune immediately after bloom to keep old roses under control and vigorous. Leave some of the bright red hips for fall and winter color.
Ever-blooming varieties can be lightly trimmed or tip-pruned several times a year, as they flower on new growth.