Pruning Roses

Pruning is the science of removing growth to achieve one or more goals: keeping the flower healthy, making it more productive, controlling its size, or encouraging it to grow in a particular shape or direction. The amount, type, and timing of pruning depends on the type of rose, the hardiness zone of the garden, the amount of winterkill, the condition of the plant, and what you want from your roses. A rose that is not pruned well will soon grow tall and lanky, and its flower production will be poor. Pruning stimulates new growth, an important factor in flowering because many varieties produce flowers only on new canes. Roses vary in their need for pruning. All hybrid teas, floribundas, grandifloras, and miniatures require heavy annual pruning to keep them in top shape. Climbers may need heavy pruning or only a light shaping, depending on the time of year and other circumstances. Many shrub and old garden roses need only the annual, light pruning you would give to other woody plants in the garden.

Pruning redirects growth in the plant. When portions of a plant are removed, it uses its remaining buds to form new stems and leaves. The food necessary to grow new parts comes, for the most part, from the root system, where much of the plants' food reserves are stored. If the root system is well established and has a good supply of food, the plant will be able to quickly replace what it has lost and even grow beyond that point. If a plant is weak and is severely pruned, it will take much more time to regain the capacity for growth it had before it was pruned. If the top growth cannot occur quickly enough to replace the food supply in the root system, the roots will starve and eventually the plant will die. It is essential that pruning be kept to the minimum necessary to accomplish your purpose.

Tools

To do a good job of pruning, you have to have the right tools. This does not involve a major investment. Although the occasional fifty-year-old rugosa rose may warrant a chainsaw, the only tools generally needed are the common hand-held pruning shears or secateurs and, for large old canes, a pair of long-handled lopping shears.

Pruning shears come in several designs and in a wide range of prices. A precision crafted pair of pruning shears that is kept sharp is a joy to use. A poorly made pair will cause nothing but aggravation, will not cut cleanly or easily and will probably have to be replaced much sooner than a well-built pair. The best types even come with replaceable parts. The best all-around shears for removing rose stems, flowers, and leaves are the hook-and-blade type, with two opposing curved blades. Choose the larger pair your hand can comfortably hold.

Another tool you may find useful is a small hand-held pruning saw. With their thin, sharp blades, these are excellent for getting into hard-to-prune areas or for removing branches that are too large for shears. Most of these saws cut on the pull stroke. For delicate work on smaller wood, a thin-bladed sharp knife is often the ideal tool. It is light, easy to maneuver and capable of smooth, clean cuts.

Lopping shears - heavy-duty, short-bladed shears with long handles - easily cut out thick canes and to prune large old garden roses, shrubs, and climbers.

Anvil shears - a general-purpose type with a straight blade that strikes against a blunt surface - are less desirable because they can crush stems as they cut. This may cause the stems to die back or become prone to invasion by insects and diseases. The only task suitable for the safe use of anvil shears is removing dead wood.

The last ones here are gloves. Going into a rose bush without gloves borders on masochism. You can bet you're going to come out with blood on your hands, or worse, needle-thin thorns imbedded in your skin; if these are not immediately removed, they will remind you of your foolishness for many days.

Roses should never be trimmed with hedge clippers, even if they are grown as a hedge. These tools are designed for overall shearing, not the selective pruning that roses require.

Be sure to keep pruning shears and saws sharp. Dull shears and saws make pruning more difficult, and they leave jagged cuts that heal slowly and admit insects and diseases. If your tools become dull, touch up the blades of pruning shears with a sharpening steel, hone saw blades with a file, or have both tools professionally sharpened. If necessary, buy a replacement blade.

Make sure that your tools are kept clean; contaminated shears and saws can spread disease. Apply rubbing alcohol to disinfect pruning tools or make a solution of 1 part household bleach and 9 parts water. Using a clean cloth, wipe the tools with whichever disinfectant you choose or dip the tools in a container holding the liquid.

In areas of high humidity, wipe shears and saws dry after each use and store them in plastic bags to retard rusting. Rubbing a thin coat of oil on the blades also helps prevent rust. Pruning shears with a nonstick coating on the blades are not as likely to rust, but the bolt holding the blades together may be rust-prone.

How to prune roses - the basics

Pruning in warm and cold climates

In warm climates where rose plants grow quite large, pruning to the recommended height is not desirable, because it will remove too much of the plant. Instead, prune away about one half to two thirds of the plant each winter or early spring by removing the older canes and shortening the remaining canes. In cold climates where there is a great deal of winter damage, pruning heights may be determined for you by the amount of winterkill. Prune canes down to where there is no more winter damage, even if it is almost to the ground.
The higher a plant is pruned, the earlier it will flower. But don't jeopardize the health and vigor of the plant by pruning too high just to have blooms a few days earlier. There is little advantage to pruning your roses lower than the heights prescribed above; unlike disbudding (see below), it will probably not make the plants produce larger flowers.

Preventing disease

Although black spot and other fungal diseases manifest themselves on leaves, their spores can overwinter on rose canes. If these diseases plagued your roses during the previous summer, you should prune them lower than recommended, thereby cutting away and discarding much of the source of the problem. Although you won't be able to see the spores on the canes, you can be assured that cutting off a few extra inches during spring pruning will reduce the number of spores somewhat. Never leave rose prunings on the ground. They look unsightly and harbor diseases and pests that may potentially reinfect the plant or spread to others.

When to seal cuts

Pruning cuts more than inch in diameter can be sealed with pruning compound, orange shellac, or grafting wax (available at garden centers or hardware stores) if boring insects are a problem in your area. Pruning compound and orange shellac are the easiest to use because they can be painted on. Otherwise, sealing is not necessary. Some types of white glue, which is sometimes used as a sealant, are water soluble and will wash away with the first rain or watering; they should therefore not be used.

Timely inspection after initial pruning

Several weeks after you have pruned, take a second trip through the garden with your pruning shears. If you pruned early in the year, a late frost may have caused minor dieback on some of the canes. This dieback should be removed. Cankers that were not apparent at pruning time may be visible and should also be pruned away.
Don't be too harsh when pruning young plants. Until plants are well established and have been growing robustly for two to three years, remove only weak, damaged, or dead wood. Shape and shorten the plants without cutting away any of the older canes. In the following years, old canes can be removed as new ones develop.

Tips for pruning tall plants

New growth starts at the growing point immediately below a pruning cut. This is especially important to bear in mind when pruning back large, overgrown plants.
If your ultimate goal is a plant 6 feet tailor a climber trained to cover a section of fence 8 feet long, you must prune the plants shorter than the desired size in order to allow for new growth. If your goal is a 6-foot-tall shrub rose, you should prune it to about 4 feet tall. Different plants have different growth rates, so gauge your pruning according to the past behavior of the plant.

How to prune roots

Roots can be pruned as well. When you plant or transplant a rosebush, prune off broken or damaged roots. Remove about one-third off the tops of the canes to compensate for this root loss. Before transplanting a large rosebush, it is a good idea to prune the roots with a spade by digging in a circle around the plant. Do this one to six months before the transplant so that the root ball will be more compact and easier to move.

How to prune different kinds of roses

Just as roses vary, so do pruning methods.

Hybrid teas, floribundas, and grandifloras

On hybrid teas, floribundas, and grandifloras, once you have pruned the diseased, damaged, weak, or excess canes, select three or four of the newest and healthiest remaining canes and cut off the rest flush with the bud union, using pruning shears or a saw if necessary. Next, prune the remaining canes of hybrid teas and floribundas to a height of 12 to 18 inches above the bud union, and those of grandifloras a few inches higher. Floribundas used as hedges can have five to six canes left on each plant, and can be pruned to 24 inches high so that they will grow denser and taller and produce more flowers.

Miniatures

Prune miniatures to about half their ultimate summer height. Up to six strong new canes can be left on the plants after pruning; the more canes you leave, the fuller the plants will be.
Roses grown in decorative containers should be pruned so that they will be in proportion to the size of the container when they are in full bloom; this may mean shorter or higher pruning than is normally recommended.

Climbers

Because climbers bloom solely on old wood, they are pruned somewhat differently than bush roses. In early spring, while the plants are still dormant or have just started to grow, any dead or damaged canes can be removed, as can those that are too long or misshapen. However, leave all other pruning until after the plants first flower so that you do not remove any flower buds. This is especially important with climbers that bloom only once a year. Those that repeat their bloom may actually be encouraged to have a heavier second bloom if they are properly pruned after the first bloom. The oldest canes should be removed to the bud union to leave room for new growth. Also thin out dense growth as well at this time.
Removing flowers as soon as they fade encourages some climbers that would not otherwise flower again to repeat their bloom during the summer. Climbers will bloom more heavily if trained along a fence or a trellis and if the ends of the canes are directed to grow down toward the ground. This forces the plants to produce more laterals. As new canes of climbers grow, they must be trained into position and tied to their supports with cord, string, or twist-ties.

Shrub roses and old garden roses

Shrub roses and old garden roses, including species roses, do not require severe pruning unless overgrown. In early spring, cut out weak, damaged, or dead wood. Prune only to shape the plant or control its size. Leave the plants as large and as natural looking as space permits. Perform heavy pruning either in early spring or after flowering, depending on the type of plant. Many old garden roses-albas, centifolias, and moss roses in particular-have long, supple canes that can be bent over and pinned to the ground. This practice makes these plants easier to control and gives them a bushier appearance. It also encourages the formation of new basal breaks (new canes that grow from the base of the plant). The canes often root at the point where pegged to the ground, and new plants that form can be left in place or transplanted.

Polyanthas

Polyanthas are hardy plants that, like many old garden and shrub roses, seldom suffer winterkill. They are therefore pruned more like old garden and species roses than like hybrid teas, floribundas, and grandifloras. If they are not overgrown, trim only to remove old, damaged, or diseased canes. If they are overgrown, prune them in early spring, to about half their former height, and remove the oldest canes. Leave them on the bushy side.

Tree roses

Tree roses are pruned like modern bush roses, but they must be symmetrical to be most attractive. Prune canes to about 12 inches beyond the bud union at the top of the trunk and leave them as evenly spaced around the plant as possible. Leaving four to six canes on each tree rose will produce a full, attractive-looking plant.

Pruning the new rose

A well-grown and well-handled young rose has a healthy root system endowed with numerous small, fine roots and several sturdy stems filled with the food necessary for next season's growth. Such a young rose, if planted in good soil and kept watered, should grow well and require only moderate pruning when planted. Unfortunately, many of the roses that you purchase have been underfed, grown under poor conditions, dug carelessly with a machine set at an improper digging depth or simply allowed to dry out somewhere along the often tortuous route from the nursery to your garden.

Soak your plants for at least 12 hours but not more than 24 hours. Cut off all dead wood and the top stems to only a few buds. Because the roots are going to be very slow to absorb water, they will not be able to adequately supply it to all the emerging buds and the top will most likely wither, often followed by the death of the entire plant. By concentrating all its energies into a small area close to the root system, the plant can usually supply enough water and food to the remainder for vigorous growth.

When pruning your new rose, make your cuts so that the last bud will grow outward. If you leave an inward-facing bud, you will often end up with crossed branches that will need to be pruned again later. Make your cuts so that they slope slightly away from the bud. Cut fairly close to the bud so that you will not end up with a dead stub, which can become infected with canker, but not so close that the bud will be in danger of drying out. An eighth of an inch (3 or 4 mm) is about the right length.

Examine the roots before planting and prune off any dead ones. If the ends of any roots are ragged or torn, prune them off cleanly. Do not prune any more than necessary from the root system. The more roots available to the plant, the more water and nutrients it will be able to absorb and the quicker it will be able to recover from transplanting.

Disbudding

Disbudding is a type of pruning aimed at producing a single, large flower at the top of the cane or forming a more uniform spray. To produce a single, large flower at the top of a cane, you remove all flower buds below the top one. This forces the plant to devote all its energy to growing one flower that can bloom twice as large. Disbudding is necessary for producing show-quality hybrid teas, grandifloras, and climbing hybrid teas, which must be exhibited with one flower per stem in order to qualify for the highest awards.

As soon as small secondary buds are visible around and below the central flower bud, remove them by rubbing them away with your fingers or the point of a small implement such as a toothpick. If you wait too long to disbud and the flower bud is an inch or more across, unsightly black scars will form and remain. Some roses naturally produce only one bloom per stem and will not require disbudding.

Roses that bloom in sprays, such as floribundas, grandifloras, climbers, and some miniatures, naturally grow in such a way that the central flower bud opens first. As it fades, the surrounding flower buds open. When the faded central flower is cut away, a large gap remains in the center of the spray. To prevent this, remove the central flower bud as soon as it appears. The remaining flowers will fill in the gap, coming into bloom simultaneously for a prettier effect, although flower size will not increase. Floribundas can be exhibited with one bloom per stem, but they are usually shown as sprays.

Miniatures can be disbudded or not, depending on the effect you wish to achieve and whether you want large flowers on single stems or uniform sprays. Polyanthas, climbers, shrub roses, and old garden-roses are rarely disbudded, as this would destroy their natural appearance. Their beauty rests in the large clusters of flowers they produce.

Maintenance pruning

Successful pruning can be accomplished in either late fall or early spring. If pruning in late fall, wait until the leaves turn color and start to fall. The longer you wait, the more food will be delivered to the root system and the more vigorous your rose will be in the spring.

Pruning too early in the fall can initiate soft late growth that may not withstand hard frost and will winterkill. Most growers still prefer early spring for their pruning. Many of the roses we grow in the north will kill back a certain percentage each winter. If you wait till spring to prune, it will be easier to assess the amount of damage that the plant has suffered, and the plant can be pruned accordingly. The dead portions can be removed and the remainder shaped. However, spring can often be a very busy time for gardeners. If you know that time will be at a premium in the spring, by all means prune in the fall. The hardier varieties will probably not suffer. Just leave the more tender types till spring.

Pruning can range from removing unwanted buds to severely excising canes. Proper pruning stimulates growth at the buds closest to the cut, which produces new flowering stems.

The first step in pruning any type of rose is to remove any dead, damaged, diseased, or weak and thin canes, cutting them off flush with the bud union or, in the case of own-root plants, flush with the crown. Look for any canes that are broken or wounded, or that have cankers (dark, sunken lesions caused by a fungus), and prune below the injury, at the highest point where the pith (the central portion of the cane) is healthy and white. Make the cut exactly 1\4 inch above a growth bud. If the injury extends below that point, cut to a lower growth bud.

Next, remove canes that are growing into the center of the plant or those that cross each other. Canes that grow inward keep light and air from the center of the plant and will eventually cross, chafing one another. These abrasions can become entry points for insects and diseases. Using shears, cut these canes down to their origin, whether that is another cane, the bud union, or the crown. It is important to keep the center of the plant open to let in sunshine and allow air to circulate freely.

Always prune to an outward-facing bud so that canes do not grow into the center of the plant. Prune close enough to the bud that no stub remains to die off and harbor insects or diseases but far enough away that the bud will not die. A good distance is about 1/4 inch above the growth bud. Equally important, cut at the proper angle so that water runoff won't drip on the bud or collect in the cut and retard healing. The ideal angle is 45 degrees, slanted parallel to the direction of bud growth.

Summer pruning

Flowers are produced at the ends of secondary stems, which grow from the main cane. Though you may not think of it as such, gathering these flowers is a form of pruning.

How to remove blooms

Whether you are cutting flowers for an arrangement or removing flowers that have faded (a technique known as deadheading), follow the same rule: Cut the flower stem no shorter than just above the first five-leaflet leaf below the flower you are removing. This is the point from which the next stem will grow and bloom. If you cut to a three-leaflet leaf instead, numerous small growth shoots will appear at the top of the stem but will never grow into sturdy, flower-producing stems.
When removing flowers from tall and vigorous roses, take the opportunity to shorten and shape them. Cut the stems down as low as you want them, but leave at least two five-leaflet leaves per stem to contribute to food production. Do not remove more than 25 percent of the foliage. If you do, you will send the plant into shock and a short dormant period. First-year plants should be pruned only slightly when removing faded flowers, to encourage growth and foliage production.

When to prune flowers

Old blooms past their peak should be pruned away as soon as possible. This not only keeps the plant looking neat and the ground free of fallen petals but also encourages new growth and flowers sooner.
To encourage repeat-blooming climbers to produce a heavy second bloom, prune and deadhead them as soon as the first flush of bloom is finished. Cut back the secondary stems, leaving two five-leaflet leaves on each. A new stem topped with a flower will grow from each leaf axil, the point where the leaf meets the stem.
Deadheading should cease as summer turns to fall because the new growth it encourages will probably not have time to produce flowers before the frost. The younger issue will also be more susceptible to damage from winter cold and wind. Leave the last roses of summer to fade naturally, and you will have plants that can better endure the rigors of winter. The only pruning that should be done in fall is to remove any tall canes that might be damaged by the wind or to shorten the canes enough to fit under rose cones or other winter protection.
Shrub roses, old garden roses, and climbers that bloom only once do not need to be deadheaded. After the flowers have faded, fruit known as hips will form. Rose hips can be harvested for cooking after they have ripened and turned yellow, orange, or red. You can also leave them as a treat for birds.

Pruning hedges

The first few years are critical when developing hedges. Once you have decided upon the general shape of your hedge, remove the growth that is beyond the imaginary planes of the hedge's sides and top. As the plants continue to grow, your spring pruning will be removing more material each year. It may also be desirable to prune after the first flush of flowering to remove wayward branches. Always be sure to keep the base of the hedge wider than the top so that adequate light is available to the entire surface of the hedge. If you try to maintain a vertically sided hedge, or try to curve the lower edge to form a ball shape, the bottom section will not receive enough light and will become open with only the branches showing.

As the hedge ages, you should systematically remove the oldest canes in the plants. A few canes removed each year will not create large and noticeable holes, and will encourage new and more productive wood to form. Your hedge will flower better, and you will be creating enough space for light and air to reach the inner parts of the hedge.

Roses lend themselves to an informal style of hedge. Although it is possible to create a more formal geometric style with careful attention to pruning, the continual shearing needed to maintain the sharp edges of such a hedge tends to form a rather dense outer "skin," which does not allow good light and air penetration into the interior of the hedge. By pruning too often you will destroy many of the developing flower buds and your hedge will not be as colorful. If you desire a formal hedge, it is probably advisable to stick with plants that lend themselves better to this use.

Pruning older roses

When speaking of hardy roses, we generally mean shrub types. Many of these are vigorous, permanent elements in the landscape and will endure for decades. As they mature they gradually thicken, often becoming very dense. This can result in plants that are really empty shells. The center of the bush receives very little light. As a result, no growth occurs on the inside, and only the outside branches put on new growth.

As the pruner, your job is to thin these bushes so that light can penetrate all sections of the plant. Ideally this is an ongoing process, which begins when the plant is young and continues annually. However, you may have to deal with a plant that has been neglected and must be rejuvenated. In the worst of cases it may be advisable to tear out the plant and either replace it or dig out a section of the plant and treat it as a small new plant. If you wish to keep the plant, you should begin by pruning out some of the older canes. This can be a tough job, requiring powerful long-handled shears or a good pruning saw, and thick gloves. Prune these old canes at ground level. If the plant is very large, prune out some of the canes one year and the remainder the following year. As light penetrates into the plant it will stimulate new growth, which will tend to be more floriferous than the older growth. Gradually cut back the top of the plant as well if you wish to lower the height. Again, this may take a few years. Some old roses can be cut nearly to the ground and will rebound to form a lovely bush, but this treatment can often result in death, particularly for species such as Rosa foetida and its hybrids.

Suckering problems

A rose can be either on its own roots or budded or grafted onto a rootstock. If your rose is on its own roots, then any suckers that occur from below ground will have the same flowers and growth habits. The vigorous shoots that grow from the base of an own-rooted plant will branch and be the source of many new flowers.

If your rose is budded, however, the suckers that grow from below the bud union will be quite different from the top. It is essential that these suckers be removed as soon as they are noticed. They should be pruned off at the point from which they are growing out of the main stem. If a stub is left, it will usually grow several new shoots from the remaining buds. If pruning with shears is difficult, the shoot can be pressed down at the base until it breaks off the main stem. The injury to the stem can result in infection with crown gall or other diseases, but in actuality it rarely harms the plant and is often the most effective way to deal with suckers. Burying the graft union well below the surface will go a long way toward lessening the incidence of suckering.

Further maintenance

A few pruning techniques can be used with good effect during the growing season. When a cluster of flowers has finished blooming, that section of the stem does not grow any more. New growth starts from the first vegetative bud below the flower cluster. If the old cluster is pruned off, it will stimulate this bud into active growth and within a few weeks, you can have more bloom. This is effective only on repeating roses. Removing the old blooms will also eliminate the possibility of seeds forming. The plant spends a good deal of energy on seed formation, and when these old blooms are pruned off, the plant has more energy to form new growth. Obviously, if you want rose hips you won't want to practice this technique.

Some roses leave their petals in a messy, brown lump when they have finished blooming. The removal of these spent blooms, or "deadheading", will help to maintain a fresh look to the plant and will encourage rapid new growth.

Be on the lookout for problems such as rose galls. These swellings are formed by small insects that lay their eggs in the stems. Upon hatching, the larvae feed on the inside of the stem, causing it to swell. If allowed to complete their life cycle they will infect other roses. Cut out any unnatural swellings as soon as they are noticed. Various infections such as cankers should be cut out as soon as you notice them. These often start on dead wood such as pruning stubs or winter-injured branches. They can quickly work their way into live tissue and cause a great deal of damage if not tended.