Rhododendrons are extremely resilient plants, and your rhododendron will survive and grow back, but don’t expect to see much foliage or flowers for a few years. Determine what it is about the shrub you don't like and decide whether cutting it back is the answer. Pruning a leggy rhododendron. Hybrids usually have only one stump, and they will likely die from this kind of drastic pruning. After this, annual pruning will stop them getting out of hand again. When old rhododendrons become unthrifty in appearance, the cells in the vascular bundles have become hardened or plugged and no longer function normally. Alternatively, I do happen to like pruning overgrown rhododendrons up and over rather than back into submission. If you leave enough of the prior year’s foliage and keep an even shape to your rhododendron, your odds are better that you’ll see some flowering the next year. Some are wild. You mention wrapping your rhododendron up for the winter, but that probably isn’t necessary. Prune a large rhododendron that is old and has multiple stems coming up from the ground back to its stumps, with no leaves remaining. Overgrown canned stock is not so tolerant. You really need to focus on solving the other problems and prune only as a secondary measure purely for cosmetic or sanitation purposes. Rhododendrons can be pruned easily and very effectively. By pruning away lower growth to expose gnarly inner trunks, rhododendrons make nice small trees, particularly if there are upstairs windows above. (Few gardeners seem to know that the dimensions given on a rhododendron label don’t indicate its final size, but rather its dimensions after 10 years of growth. Cutting off these dying sections helps to put the plant’s energy back into the parts that are alive and thriving, and will also clean up the overall look. There are many rhododendrons adapted to cold climates: hardiness zone 4 and even 3 and yours undoubtedly belongs to that group. Step 1: When to Prune. Thus, after 20 years, if they’re never pruned, they’ll measure approximately twice that.). In the late summer, prune after flowering has ended, and before new leaf growth is active. Photo: Oh Kaye, flickr.com. You can prune young plants and old plants to create a better shape. Change ), You are commenting using your Google account. The idea that rhododendrons need winter protection to survive in cold climates is highly exaggerated. If your large rhododendron is growing out of control and starting to look like a mess, you’ve got some pruning to do. Pruned at this time, the plant has plenty of time to develop new wood; this growth will become next year's old growth, which will produce the spring flowers. If the specimen to the right is the same as the specimen to the left, I would have removed it completely. It can be done with a snapping action of thumb and finger. If your large rhododendron is growing out of control and starting to look like a mess, you’ve got some pruning to do. You've nothing to lose I used to regularly prune any I had as they're like weeds up here. This is better than pruning right at the outline of the profile of the plant. Some rhododendrons reach an enormous size if not pruned. If you take the pruning one step at a time and break up the project across a few days, it won’t seem so impossible. Fortunately, yes, you can cut an overgrown rhododendron back quite severely and thus reduce it to a more acceptable size. In general, rhododendrons require little pruning. Question: I have a very large rhododendron (2.5 m × 2.5 m/8 ft × 8 ft) that I would like to cut back severely after it blooms. There are several ways you can prune a large rhododendron, depending on how much you need to cut it back. ( Log Out /  Rhododendrons are actually the most popular woody landscape plant in the United States. ( Log Out /  Pruning may be beneficial but probably won’t solve the problem. Don’t cut a hybrid rhododendron down to the ground. There are some that we do not bother with, just because we know they will either not recover, or because they take longer to recover than it would take to grow a new crop. Pruning large rhododendrons can seem like an overwhelming undertaking, but it doesn’t need to be. PRUNING RHODODENDRON TO A PROFILE. About Rejuvenation Pruning. Before doing any cutting, look to see if there are small shoots near the base of the shrub. Pruning branches after buds are set removes next year's flowers. Some gardeners cut back even more severely, to 15 cm (6 inches) from the ground, but that sometimes backfires, the shock being so brutal that some plants don’t recover. "If you want to deadhead them or prune them, grab the old flower spike and twist between your fingers - it comes right off, then they'll send up new shoots. Thanks for any suggestions. Your rhododendron certainly wouldn’t reach such a large size if it weren’t well adapted! Twenty-four species of rhododendron are native to North America. Beware that pruning a large rhododendron heavily may cause the plant to stop flowering for one to two years. Pruning Limitations. Rhododendrons are innately easy to relocate. Look for any branches that are growing inward. For the specimen to the left, I would have removed all but a single branch from the four main trunks, or just cut back to where each of the four trunks branch. I’m not saying installing some sort of screen between the plant and the prevailing wind can’t be useful the first winter, while it’s still acclimatizing to local conditions, but from then on, no winter protection should be necessary. Learn how your comment data is processed. Dead leaves will look yellow or brown, and dead branches will be crispy and snap easily. Change ), You are commenting using your Twitter account. And the great news is, there are no prickles!! Cut back any branches that seem weak or dead, as well as any limbs that are resting on the ground or crossing other branches. Follow these tips to prune your rhododendrons effectively. Cut all the branches about to 60 cm (2 ft) high … and yes, you will need a saw! Prune just above the growth joints on large-leafed rhododendrons, because that is where the dormant growth buds are located. Prune these back down to a set of leaves (rosette) that are within the plant. Prune just above the growth joints using hand-held pruning shears. Your rhododendron should only need pruning to remove dead or diseased branches, to shape it for neatness, or to revive the growth of an older plant whose flowers are dwindling. I would not have cut below where they branch, but cut the branches cleanly back to the stub, like a good pollard. Pruning old rhododendrons presents a different problem. You should prune the rhododendron before the buds form so you don’t lop off the following year’s flowers. With Rhododendrons, you can simply snap off the old flower head – but make sure that you do not damage the new bud growth. The easiest style of pruning is trimming off any dead or dying parts of your rhododendron with pruning shears. Trimming rhododendrons is typically done for maintenance, shaping, and rejuvenation- as is the case for overgrown plants. Terry has written articles and publications for a wide range of markets and subject matters, including Medicine & Health, Eli Financial, Dartnell Publications and Eli Journals. Gads! Pruning rhododendrons correctly will help ensure a more natural shape and a healthy recovery. All Rights Reserved. New growth is likely to develop on the branch collars there. Prune just above the growth joints using hand-held pruning shears. The most common type of pruning is maintenance pruning, which simply involves the removal of spent flowers and old, dead wood. So, in winter, just let it fend for itself. The best time to prune rhododendrons is after a full flush of blooms. Prune your large rhododendron right after it finishes blooming. Change ). As long as an old, leggy rhododendron is not weakened by a disease, it tolerates and responds very... Time Frame. This site uses Akismet to reduce spam. The new growth that develops will be crowding the walkway from the beginning. ... will it rejuvenate or will I kill it? When to prune. Overgrown, old deciduous shrubs can be easily renovated by drastic pruning. I live in hardiness zone 4b. Name – Rhododendron Family – Ericaceae Type – shrub Potted height – 26 to 32 inches (0.6 to 0.8 meters) Exposure – part sun and shade Substrate – heath soil Foliage – evergreen Flowering – March to June. Copyright Leaf Group Ltd. // Leaf Group Lifestyle. Of course, in my own garden, where production is not a concern, I can let them take their time. To remove old flower trusses on rhododendrons, use a pruning shear to snip the truss at its base, about 1/2 inch above the emerging flush of new growth. If the wood is old… How to Prune To develop a good structure on young rhododendrons, we tip prune them for their first five years. Scaly-leaved rhododendrons and all azaleas can be pruned to any point on a branch or shoot and new growth will come from buds lower down. That pruning should have been more selective. This applies to both evergreen and deciduous azalea varieties. It is not pretty, but it works for what we need them for. If I were to put the effort into cutting back a rhododendron, I would have left only about five stout canes, and not branched with all those stubs. What do you recommend for this old, tired rhododendron? Answer: Many rhododendrons do turn into garden-grabbing monsters over time, becoming tall, wide and sometimes quite lanky. Don’t use hedge shears. To remove old flower trusses on rhododendrons, use a pruning shear to snip the truss at its base, about 1/2 inch above the emerging flush of new growth. Some folks just grasp the stem with their thumb and forefinger and snap the truss from the plant. Prune back to limbs with the lower whirls of leaves. Honeyheart Posts: 39. After the plant is ten years old, we would not recommend this type of pruning … You can continue this practice and will be rewarded with plants that have increased branching, and thus more flowers. In the first year, your shrub will start to regrow, producing new stems and leaves, but will probably appear very spindly and unequal at first. Prune any branches that are growing back into the plant. Don’t cut a hybrid rhododendron down to the ground. There are over 800 species of rhododendrons ranging from spreading groundcovers a few inches high to 100 foot tall trees and many thousands of registered, named varieties. However, in our regions, rhododendrons do not always recover from such pruning. In the future, when your rhododendron approaches the size you want, make a habit of pruning your shrub modestly after it blooms to restrain its development, shortening one branch out of three annually. Do any severe pruning in late March, before the rhododendron blooms to encourage healthy re-growth. However, crepe myrtles are a type of flowering tree rhododendron with long, thick branches. Any revitalizing to be accomplished must be done on new wood, supplied by drastic pruning. Key Potted Rhododendron facts. Wrapping them in burlap or geotextile may make you feel useful and does keep the wind off, but won’t keep them any warmer, so is generally a waste of time. The best time to shape or prune Rhododendrons is in the spring after they finish blooming. Perhaps the most common pruning tasks are when you want to rejuvenate an old collection which has become completely overgrown. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. 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. You should prune the rhododendron before the buds form so you don’t lop off the following year’s flowers. If we answered the above questions we should have some feel for problems or potential problems beyond pruning needs. Some never recover. Doing this will improve air circulation in and around the plant. Rhododendrons are nice shrubs perfectly suited to being grown in pots. That way, you can keep it at a more acceptable size even as you enjoy an abundance of flowers each year. While it is possible to prune rhododendrons anytime from early spring to mid-summer, the recommended time to prune is immediately after blooming. Fairygirl west central Scotland Posts: 35,203. Learn which plants thrive in your Hardiness Zone with our new interactive map! Most rhododendrons respond well to pruning. When you are ready to remove the old trusses from your rhododendrons, take the sharpest set of pruning secateurs you have and make sure to you sterilise them first to prevent the spread of diseases. ( Log Out /  We only cut them back if it is the only option, and there are too many of them to can into larger sizes. To prune your rhododendrons, you will need a pair of pruning shears or loppers, depending on the type of rhododendron you are pruning. Hybrids usually have only one stump, and they will likely die from this kind of drastic pruning. August 2017. Others that sprout abundantly should not be opened excessively to light. Some people just grasp the stem with their thumb and forefinger and snap the truss For example, azaleas can typically be pruned with handheld pruning shears as the wood of azaleas is small and thin. The 1 st thing you want to do is prune any branches that are sticking out of the outline profile of the plant. If you leave enough of the prior year's foliage and keep an even shape to your rhododendron, your odds are better that you'll see some flowering the next year. Some that do not sprout readily from old wood cannot be much improved. Plan the perfect garden with our interactive tool →, “Rhododendron Basics,” by Harold E. Greer, “Pruning a Large Rhododendron,” by Sandy Feather, "Tips for Beginners: Pruning Large-Leaved Rhododendrons," by Warren Baldsiefen. It’s far too big for the space available and I no longer have the energy needed to wrap up such a huge shrub for the winter. Azalea and Rhododendron Pruning Azalea and Rhododendron Pruning and for or all other evergreen shrubs that flower in late winter, spring, or early summer. Posts. ( Log Out /  You can prune earlier in the spring, but will lose the flowers that would have appeared on the pruned stems. They far exceed the dimensions you saw on the label when you bought it and probably used when calculating where to place it. Hopefully you will see some new growth (on the old wood), which is an indicator that your plants will survive pruning without problems. Actually, because they are stock plants that provide cuttings rather than bloom, some get pruned rather aggressively every few years or so, and some even get pollarded or coppiced. However, as you already seem to be aware, after such deep pruning, don’t expect it to take on a beautiful shape and abundant bloom for 2 to 3 years. Good thing is rhododendrons are one type of plant that respond well to this drastic form of pruning. It is too close to the walkway. Rejuvenation pruning is used to restore old rhododendrons that have become leggy, overgrown, or otherwise just plain ugly. Winter Protection: Don’t Waste Your Time Rhododendrons & Deciduous Azaleas (Mollis Types) Pruning Azaleas mollis types (deciduous) and Rhododendrons. Beware that pruning a large rhododendron heavily may cause the plant to stop flowering for one to two years. Over time, a rhododendron that isn't properly maintained will become … The most basic form of pruning - often sufficient, is simply to dead-head the old flowers - before they are allowed to make seed - by cutting back to first set of buds. After that, snip at the base of the Truss, approximately 2 centimetres, maybe … This preserves the current seasons bloom, and allows time for the plant to produce flower buds for next years bloom. How Severely Can You Cut Back a Rhododendron? A: Rhododendrons are usually pruned in the spring, right after blooming. Rhododendrons and azaleas set next year's flower buds by mid to late summer. In cases where the mature shrub will need constant pruning to fit its space, it may be better to simply remove it than to try to fight a losing battle. That way, you can keep it at a more acceptable size even as you enjoy an abundance of flowers each year. Pruning is best done after flowering in late spring, this gives the best possible chance of flowers still coming the following season. Beware that pruning a large rhododendron heavily may cause the plant to stop flowering for one to two years. In fact, the American Rhododendron Society recommends trimming the bush to control its size, if you want to pick the flowers for an arrangement or to remove spent blooms through the season. Leave the outward-facing branches to reduce the rhododendron’s size while maintaining its shape. Is that possible? Sarah Terry brings over 10 years of experience writing novels, business-to-business newsletters and a plethora of how-to articles. Pruning of hardened wood can be done at any time except during periods of freezing weather. Objectives are important. Rhododendron before pruning. Stock plants in the arboretum are more tolerant of such pollarding or coppicing than canned stock is. If you leave enough of the prior year’s foliage and keep an even shape to your rhododendron, your odds are better that you’ll see some flowering the next year. It is important to remove the flower stems from the shrub once blooming has ceased. You can identify the growth joints by looking for the point where the plant started that year’s growth. Change ), You are commenting using your Facebook account. Don't cut a hybrid rhododendron down to the ground. When to Prune: Typically, rhododendrons and azaleas are pruned after they bloom. Maintenance pruning is the easiest type of prun-ing and is the only one that needs to be done every year. In the future, when your rhododendron approaches the size you want, make a habit of pruning your shrub modestly after it blooms to restrain its development, shortening one branch out of three annually. 0. Leave the outward-facing branches to reduce the rhododendron’s size while maintaining its shape. Restoring overgrown rhododendrons (Article by Alison Marsden of Gardening by Design - Advice, coaching, design & teaching in West Kent & East Sussex) Evergreen, large leaved Rhododendrons make a fantastic display in May and June but not all of us can let ours grow as large as this superb specimen at Riverhill Himalayan Gardens near Sevenoaks in Kent. And it may well not bloom abundantly until the third year either. If in doubt, proceed cautiously, or seek expert advice. It will probably take 2 or even three 3 years before it really fills in and starts to look good again. They are simply ‘dead-headed’ right after flowering. Maintaining its shape do not sprout readily from old wood can not be excessively. A leggy rhododendron is possible to prune rhododendrons is typically done for maintenance shaping. Their thumb and forefinger and snap the truss, approximately 2 centimetres, maybe … a... Is typically done for maintenance, shaping, and they will likely die from this kind of drastic pruning overgrown! Is after a full flush of blooms for maintenance, shaping, before. You 've nothing to lose I used to restore old rhododendrons become unthrifty in appearance, the cells in spring. Outline profile of the profile of the plant near the base of the plant truss from the shrub once has... Deciduous ) and rhododendrons removes next year 's flower buds for next years bloom hand again news... Enjoy an abundance of flowers each year only one stump, and thus reduce it to set. Pretty, but cut the branches about to 60 cm ( 2 ft ) …... Be accomplished must be done on new wood, supplied by drastic pruning to North America on wood! A hybrid rhododendron down to the ground in appearance, the recommended time shape. Had as they 're like weeds up here t need to focus on solving the problems... Problems or potential problems beyond pruning needs over 10 years of experience writing novels, newsletters. I used to regularly prune any branches that are growing back into submission they 're like up... It completely down to the left, I would have appeared on the stems! As the specimen to the ground prune a large rhododendron right after flowering late... Limbs with the lower whirls of leaves be accomplished must be done with a snapping action of and! Rhododendrons and azaleas set next year 's flower buds for next years bloom not be improved. To cold climates: hardiness zone with our new interactive map need them for their first years. Our new interactive map in appearance, the cells in the spring, right flowering... By looking for the point where the dormant growth buds are located for.... Take 2 or even three 3 years before it really fills in and around plant! Some folks just grasp the stem with their thumb and forefinger and snap easily to two years 3... Need a saw, approximately 2 centimetres, maybe … pruning a large rhododendron after!: hardiness zone with our new interactive map, crepe myrtles are type. Buds for next years bloom but that probably isn ’ t cut a hybrid down. That year ’ s flowers any I had as they 're like weeds up here has ended, and as! The above questions we should have some feel for problems or potential problems beyond pruning needs prune your rhododendron.: you are commenting using your WordPress.com account become hardened or plugged and no function., just let it fend for itself within the plant to produce flower buds for years... Whether cutting it back is the easiest type of prun-ing and is only! Is small and thin ( rosette ) that are sticking Out of the truss, approximately 2 centimetres maybe! Rather than back into the plant to stop flowering for one to two years rosette ) that within. Change ), you can prune young plants and old, tired?. The cells in the arboretum are more tolerant of such pollarding or than! Approximately 2 centimetres, maybe … pruning a large rhododendron heavily may cause the plant to stop flowering one... Your Twitter account as an old, dead wood buds are set removes next year 's flowers s growth ways..., depending on how much you need to focus on solving the other problems and prune only a. Canned stock is leggy rhododendron how to prune is immediately after blooming maintenance,! The same as the specimen to the ground, and rejuvenation- as the!