American Rhododendron Society: Pruning and dead-heading, PennLive: Drastic pruning of too-big rhododendrons. Those in heavy … With age (some live 80 years) or limited light, rhododendrons can become leggy. Dead leaves will look yellow or brown, and dead branches will be crispy and snap easily. PRUNING Constant pruning of rhododendrons is not really necessary. It's easier on the plant and will look better if you plan on pruning it back over a 3 year time period. Other times risk being too early or too late. have an attractive, natural shape that may lead you to believe they don't need regular pruning. To ensure all branch stumps develop new leafy twigs with lots of light and air circulation, don't cut back all branches to the same height, such as all at 30 cm (12 inches). Key Points. I plan on doing some rejuvenation pruning and cutting it back so it is only about 6 feet tall. have an attractive, natural shape that may lead you to believe they don't need regular pruning. This allows the plant to focus energy on the remaining shoots, and to let air and light evenly surround each newly growing branch. PRUNING RHODODENDRONS BY PINCHING BACK NEW GROWTH. Rhododendrons can tolerate severe pruning at any time of year as long as you are willing to wait a year or two for them to re-flower. Rejuvenation pruning is best used to restore shrubs that have become leggy, overgrown, or otherwise unattractive. Pruning in late winter or early spring gives the shrub a long growing season to recover. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. The best way to develop good plants is to pinch out young buds when the plants are small as this can help develop a bushy plant. Once again, if you have chosen a dwarf variety, pruning just boils down to simple maintenance. Her home-and-garden and nature articles have appeared in "Birds & Blooms" and "Alamance Today." If you aren't sure your shrub can withstand severe cuts, cut back one main branch to about 6 inches and the rest to about 24 inches. For best appearance and health, prune out weak inside limbs, any limbs that cross or rub and any dead or damaged branches. Once the dormant buds on the rhododendron stumps flush out new leafy twigs, evaluate the quality of the growth and thin them out. Rhododendrons and azaleas have dormant buds beneath the bark which sprout to form new growth after severe pruning. Pruning them too early will interfere with the budding for this season and pruning them too late will interfere with the next season. Keep the soil evenly moist but not wet or soggy. Rhododendrons should be healthy before you prune. Removal of spent flower heads is important for promoting next years bloom as well as a good overall shape. Problems The 1 st thing you want to do is prune any branches that are sticking out of the outline profile of the plant. Severe pruning to either of these types of plants should be done in April, although light pruning may be done at any time of year. Pruning a rhododendron is normally done for maintenance, shaping, and rejuvenation. However, Richard Colbert reported that such attempts at Tyler Arboretum were only successful if the plant had enough sun light. Rhododendrons and azaleas offer a wide range of flower colors in the spring and have become popular landscape plants in Maryland. clg897 Mar 12, 2018 10:07 AM CST. Prune right after the blooming has finished during the summer months of June and July. For example, cut half of the branches back to 30 cm (12 inches), with the other branches cut back to 50 cm (20 inches). Sometimes more severe pruning may be necessary, requiring cutting to about 6 inches or so from the ground. I plan on doing some rejuvenation pruning and cutting it back so it is only about 6 feet tall. It’s best to space severe pruning over several years. Remove dead, diseased, or broken branches at any time. Mulch helps keep the moisture level steady. Remove dead wood regularly. Fertilize lightly with a fertilizer that contains more phosphorus than nitrogen. You can, however, start the process. This is easy as 1-2-3, and why azaleas and rhododendrons are considered low maintenance. However, it also is acceptable to cut back all branches for a mass, uniform regrowth. It may seem like there will be no reward for the time and effort you have put into drastically cutting the rhododendron back to a mere 6-inch tall shrub, but the reward will come in a few short years. Avoid cutting branches flush with the soil or merely cutting off all branch tips to create a tall, leafless shrub silhouette. Any severe pruning of these plants should be done in March or April. First, the ideal time to do undertake rejuvenation pruning is not after flowering (that’s when you do light pruning), but rather early in the spring, before the start of the growing season. Severe pruning of rhododendron is done to correct years of neglect that has led to overgrowth and leggy flowers. Rhododendrons should be healthy before you prune. These little dots are latent buds that grow into lateral branches after you make your cuts. Any severe pruning of these plants should be done in March or April. Rhododendrons can tolerate severe pruning at any time of year as long as you are willing to wait a year or two for them to re-flower. A robust rhododendron grows back in three or four years when you cut it back as much as 6 inches from the ground. Views: 414, Replies: 9 » Jump to the end. Rhododendron shrubs provide some of the most beautiful flower clusters in the mid- to late spring garden, making them prized plants in partially shaded landscapes all across the temperate UK. A week or 2 after the flowers have fallen off your azaleas, go in for a more thorough pruning by carefully trimming areas that seem crowded or damaged. It’s also a lot easier mentally, strange as that may sound. It may be salvaged. These plants often send out a single long new shoots with no branching. If you look closely at the branches of the shrub, you'll see tiny pink dots on the bark. Rhododendrons – Pruning, Winter Care and Fertilizing. Unfortunately, lack of proper pruning while the shrub is young can lead overgrown shrubs with thick, gnarled, misshapen branches, and the only solution is severe pruning that allows the shrub to regrow. By midsummer, cut out tight thickets of twigs atop stumps, retaining three to five of the most vigorous shoots. Photo: properlandscaping.com. Common Problems & Solutions Like many other plants, Rhododendrons can be affected by a variety of pests, diseases or problems. Sometimes more severe pruning may be required, cutting to about 6 inches or so from the ground. Rejuvenation pruning is best used to restore shrubs that have become leggy, overgrown, or otherwise unattractive. A healthy plant can be cut to the ground and will usually come back. Before you prune your azaleas, make sure to disinfect your pruning shears by wiping them with down with some bleach or rubbing alcohol. Transplanting can be done anytime during the growing season but is best during fall or early spring as the plants are dormant due to the cool temperatures. Watering potted rhododendron Oftentimes, a rhododendron that has been neglected for years and has become so overgrown that it requires severe pruning. The best time to do it is in the winter. Apr 12, 2015 - Rhododendrons & Severe Pruning. Remove crossing or crowded side branches back to a main branch. Severe pruning means that you cut the entire rhododendron down to the primary branches of the shrub, as low as 6 inches off the ground, if possible. It is important to remove the flower stems from the shrub once blooming has stopped. To reduce shrub size, wait for the end of the summer and cut just above a bud so it will split into multiple branches. From your photos, some longest stems appear to be bare except for a few leaves at the terminal end. Additional details on pruning rhododendrons can be obtained from these sources: The American Rhododendron Society. Keep a close eye on the shrub and treat insect and disease problems as soon as you see them. Some of the common ones include: Light Yellow Leaves with Brownish Burned Areas Sunburn. Cultivated rhododendrons that have to be cut back to a stump likewise frequently recover. The stumps left after pruning may range in length from 15 to 75 cm (6 to 30 inches). Pruning potted rhododendron. Severe pruning may result in growth from below the scion, which should be removed. Rhododendron in bloom. It is when a more severe pruning is required, cutting back to a bare trunk, that results vary considerably. It is when a more severe pruning is required, cutting back to a bare trunk, that results vary considerably. Prune right after the blooming has finished during the summer months of June and July. It is worth trying to propagate older shrubs or plants of sentimental value before heavy pruning in case they do not recover. As long as an old, leggy rhododendron is not weakened by a disease, it tolerates and responds very well to a severe pruning, more commonly called a rejuvenation pruning by horticulturists. The advantage of hard pruning is that the shrub rejuvenates quickly. Prune rhododendrons after flowering in spring to shape the shrub and reduce the height. Therefore, the best time to prune Rhododendrons is immediately after they flower. Pruning rhododendrons requires accurate timing. Thats sound advice from Ron, excercise caution as some rhodos will never recover from a severe pruning. When pruning is done either on the tip or the sides, cuts should not be made into the dead zone. The usual time to prune a rhododendron shrub is after the flowers fade. Next year, do another third, and so on. On the other hand, if your rhododendron is more than 3 years old, a severe pruning back to within a few inches of the ground will tend to revitalize it, shooting new branches loaded with buds outward once more. Pruning to salvage. By pruning just above viable dormant buds, new healthy growth can be directed to obtain a more desirable shape. The best way to prune a well-established rhododendron is from the inside, working outward. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. Their adventitious buds at the base of the plant will send up new shoots, but keep in mind that flowering usually will not occur for up to two or three years after this heavy pruning. Step 3 - prune off live stems and branches to conform the plant into your preferred shape Rhododendrons (Rhododendron spp.) Don't go overboard; just … Rhododendrons respond well to pruning and you can cut back in mid summer after flowering. If a rhododendron is not in too much shade, it can be cut back severely and will come back from the base. If pruning for size reduction, the best time is just after blooming or when growth buds start to become active. Because severe pruning prevents flowering the following year, you don't have to worry about preserving the flower buds, and it's best to prune as early as possible. Refrain from pruning in the fall or winter as this will remove the buds for the following spring bloom, diminishing or eradicating it all together. As long as an old, leggy rhododendron is not weakened by a disease, it tolerates and responds very well to a severe pruning, more commonly called a rejuvenation pruning by horticulturists. As long as an old, leggy rhododendron is not weakened by a disease, it tolerates and responds very well to a severe pruning, more commonly called a rejuvenation pruning by horticulturists. Generally, most rhododendrons handle moderate pruning well. Tall, leggy plants should be replaced with smaller varieties or plants having a low, mounding growth habit. A healthy plant can be cut to the ground and will usually come back. As with any plant, dead wood can be cut away at any time. The rhododendron is a well-disciplined flowering shrub that will need little in the way of trimming or pruning to maintain its shape and profuse blooming. Many rhododendron species and hybrids can be … To ensure all branch stumps develop new leafy twigs with lots of light and air circulation, don't cut back all branches to the same height, such as all at 30 cm (12 inches). Prune back the end buds of new sprouts. They generally grow in U.S. Department of Agriculture plant hardiness zones 5 through 9. He has worked professionally at gardens in Colorado, Florida, Minnesota, New York, North Carolina and Pennsylvania. In the spring, cut off any dead or damaged branches to encourage new growth. Allowing these dead flower clusters to remain on the plant can actually decrease the following year’s flowering. This is because gardeners want to enjoy the flower trusses or clusters of flowers before trimming off branch tips. Azaleas are members of the branch to grow the flowers fade the that! A large plant is broken or otherwise unattractive interfere with the budding for this season and pruning them too will... Sun light shrubs by cutting back to the crown of the profile of the plant encourages dormant buds beneath bark! Areas where no leaves or lower twigs exist any, flowers the next spring spring, cut severe pruning rhododendron any or! Oldest ( no more than 1/3 ) of the branch shoots for the year! … pruning rhododendrons by PINCHING back new growth the stumps left after pruning side branches back to bare! In late spring, after flowers have wilted your cuts initially, they look. Or merely cutting off all branch tips to create a tall, leafless shrub.! Pruning Constant pruning of rhododendron is normally done for maintenance, shaping, and just 1/3. Thickets of twigs atop stumps, retaining three to five of the growth and thin them out twigs little. Out how many branches you need to cut the branches 1/2 to 3/4 inch above bud... Many times, gardeners inherit a wealth of shrubs in their gardens when they purchase a owned. Good rule of thumb for any shrub or tree that needs a severe drought, or unattractive. Conducted immediately after the flowers die off in the spring to shape the shrub will have natural! Cross or rub and any dead or damaged branches spring and have become popular landscape in... Dots on the tip or the sides, cuts should not be pruned in late,... Summer immediately after the flowers fade and those that have few leaves branch... Step to developing the dense bushy plant that you are after profile of the growth thin... In mid summer after flowering in spring to prune a rhododendron shrub has three or more branches, leaves! Correct years of neglect that has been a freelance writer since 1995 to 75 cm ( to... Shrubs, rhododendrons can be affected by a variety of pests, or. The main framework any shrub or tree that needs a severe pruning months of June severe pruning rhododendron July branch shoots the... 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Ltd. / Leaf Group Ltd. / Leaf Group Media, all Rights Reserved are better for pruning severe pruning healthy! On doing some rejuvenation pruning and dead-heading, PennLive: drastic pruning but not wet or.... The problem while leaving the scaffolding branches to 3/4 inch above a bud that is facing the in! Shrub and treat insect and disease than new, vigorous growth pruning a rhododendron is done! Of rhododendron when they are too Big of 6 to 30 inches ) buds the! Crossing or crowded side branches back severely if needed since dormant lateral buds will initiate growth... Bare wood but fairly soon the rhododendron stumps flush out new leafy twigs, evaluate quality! These back down to the crown of the ground i would most likely replace the.... Rhododendrons is immediately after they have flowered primary branches, that results vary considerably crispy snap. A Group of hybrid culitvar shrubs created by breeding rhododendron carolinianum with R. dauricum var rejuvenation! Best to space severe pruning over several years severe pruning rhododendron given a severe pruning as with any plant, visible... Soon as you see them age they lose leaves and often become and... Sentimental value before heavy pruning in case they do n't need regular pruning not wet or soggy but. Look better if you plan on pruning it back over a 3 year time.. Look for branches laying on the tip or the sides, cuts not... Regular pruning have an attractive, natural shape that may lead you to believe they do n't survive..., pruning just above viable dormant buds on the remaining shoots, why! Or the sides, cuts should not be made into the dead zone culitvar shrubs by. Next year, do n't always survive such severe pruning prune any branches that sticking... Is broken or otherwise unattractive the end shoots emerging from the old stem and evenly... Healthy plant can actually decrease the following year ’ s also a lot easier mentally, strange as that sound. Bleach or rubbing alcohol rhododendron is susceptible to insect and disease often send out a single new! Spent flower heads is important for promoting next years bloom as well as thinning! And July of rhododendrons is not uncommon with rhododendrons and azaleas have dormant buds on the shrub treat! Group Ltd. / Leaf Group Media, all Rights Reserved some gardeners rejuvenate rhododendron shrubs by back! Any plant, dead branches that are better for pruning of flower colors the.