Done every three to five years, this extreme method of pruning can indeed rejuvenate an overgrown or misshapen shrub, just as the name implies. I have considered setting them out to dry prior to composting but wonder if the seeds would still be viable. Rejuvenation Pruning. Flowering quince. If you have an overgrown shrub that is no longer flowering, try rejuvenation pruning in early spring by cutting all the stems back to the ground. Here is one example from my work site. That's it. Once established, most evergreen shrubs are fairly low maintenance and need little or no regular pruning. A: Rhododendrons are impressive plants in a landscape. In this case we employ pruning action three: rejuvenation, which sounds better than renovation. Pruning large rhododendrons can seem like an overwhelming undertaking, but it doesn’t need to be. If digging in fall, remove the plants carefully, shake off as much soil as possible, allow the tubers to dry for a few days and then store them in a frost-free, dry and somewhat dark place. So out came the saw as soon as the request was made. Flowering quince. Rejuvenation pruning. If not, when? Prune your large rhododendron right after it finishes blooming. Please support high-quality local journalism. Weigela. Prune your large rhododendron right after it finishes blooming. Some shrubs will have a single main stem from which the framework branches grow. A tip I have seen time and time again is: when you are doing some rejuvenation pruning, don’t forget to … Rejuvenation pruning removes most of the branches of the plant, initi- Hollies and gardenias are other shrub candidates for this pruning method. Fortunately, they are actually not too difficult to prune back. You can cut back woody branches into areas where no leaves or lower twigs exist. Plants that respond well to rejuvenation include, forsythia, lilac, and spirea. Pruning rhododendrons is not that different from pruning other types of flowers. Somewhere down the road we will be rewarded with a less unruly plant. The second type of rejuvenation pruning involves cutting off the trunk of the rhododendron shrub to 6 to 12 inches from the soil. But what if your rhodo is too big? Others that sprout abundantly should not be opened excessively to light. Deciduous shrubs that respond well to rejuvenation pruning include: Lilac. This will shorten the plant and enable you to see out your window. What do you recommend? Normal pruning takes precedence with younger shrubs. Rejuvenation pruning, can be useful to reshape a plant. Just follow the branch down to the last whorl of leaves you want to keep and cut just above those leaves. How do you treat a stem canker in a maple tree. Now is the perfect time to prune, after this year's blooms and before the buds form for next year's flowers. A: Rhododendrons are impressive plants in a landscape. This is extreme pruning! © 2020 Advance Local Media LLC. If your plant has become quite leggy with old wood, then what you’ll need to do is rejuvenation pruning. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. There are three pruning actions associated with rhododendrons. A tip I have seen time and time again is: when you are doing some rejuvenation pruning, don’t forget to … What’s yours? – Josephine County, A: You must wait until the current plantings have “rebuilt” the necessary strength in the tuberous roots to bloom again. Pruning large rhododendrons can seem like an overwhelming undertaking, but it doesn’t need to be. You can consult any good source of information on perennials to find out how this is done and when. Pruning of hardened wood can be done at any time except during periods of freezing weather. (604) 729-2234 This video, from the local garden program, Garden Time, shows you how to do this: Pruning Rhododendrons and Azaleas. Rhododendrons often have three or more main branches rising from the crown of the plant. As you have noted all are potentially invasive. Reduced to 30%. Spiraea. Maintenance pruning: Maintenance pruning is performed on rhododendrons just after they have flowered. Rejuvenation pruning works on rhododendrons because they produce small buds all over the surface of branches, even the old ones. Take your time and prune over a couple of years. Rejuvenation pruning. This may delay flowering for several years but will result in a more manageable shrub. Other times risk being too early or too late. Email: Perhaps there are other factors causing the low bloom. Drivers couldn’t see properly when turning. This works because rhodos are special. 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. With a rhododendron or azalea that lives up to their reputations as the … When to prune. This will mean that in years to come – just as the shrub is reaching its full glory, there will be a need to take drastic action by way of cutting down hard. 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. It even creates more flowers as the shrub redirects its energy into flower production rather than overgrowth. Landscaping and Property Maintenance - How renovation pruning saved Escallonias - Proper Landscaping Inc. 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. Administrative Mailing Address: This was the result. Rejuvenation pruning removes most of the branches of the plant, initi- I prefer hand pinching. Always aim to cut above these buds. I'd rather keep the rhododendron but in a much smaller version, and I'm willing to forgo blooms for a year or two to do so. My husband advocates pulling it out and planting an azalea there. Many rhododendron spe-cies and hybrids can be severely pruned and come back as good as new. Rejuvenation pruning, also called renewal pruning, involves cutting some types of shrubs almost down to the ground, leaving only 6 to 24 inches. Note to readers: if you purchase something through one of our affiliate links we may earn a commission. – Anne Schmidt, OSU Extension Master Gardener, Dahlia breed: Scott's Caldera Katie Currid/The Oregonian LC-LC-, Q: I have several dahlias in my yard that grow well but have little to no bloom. It's best to remove only 25-30 percent of the leaves in a year, as hard pruning will stimulate the plant to put out vigorous, messy growth. Unlike many shrubs, Rhododendrons seldom require pruning, although they may benefit from an occasional maintenance trim. The most common type of pruning is maintenance pruning, which simply involves the … Red-stemmed dogwoods. Photo: properlandscaping.com. When pruned properly, the result is a fuller plant that produces an abundance of flowers. Many rhododendron spe-cies and hybrids can be severely pruned and come back as good as new. However, on very old wood, the dormant buds may have atrophied and are not viable. Mark Graves/The Oregonian/OregonliveLC- Mark Graves. Most rhodos produce seeds and you can get your rhodo to concentrate on growth by removing the spent flowers. This growth may need subsequent thinning out to select the strongest, best placed shoots. The main goal of rejuvenation pruning is height reduction, and in many cases, plants may be reduced in height by 75 to 90 percent. Pruning is spread over two or three years to gauge response or maintain the natural shape. After a rhododendron shrub is severely cut back for rejuvenation, expect few, if any, flowers the next spring. You will be removing all old wood, and the plant will begin producing new juvenile stems and new foliage shortly after pruning. First, the ideal time to do undertake rejuvenation pruning is not after flowering (that’s when you do light pruning), but … This makes neat little mounds of twigs that will explode with new growth come spring. Remember! This makes neat little mounds of twigs that will explode with new growth come spring. Forsythia. Spiraea. I made this vid for my daughter to show her what I've done in her dad's yard at her childhood home. The larger-leafed rhododendrons have many dormant buds that can be forced into new growth. What this translates to is after the frost in fall when the plants die back. Kym Pokorny | For The Oregonian/OregonLive. Plants that respond well to rejuvenation include, forsythia, lilac, and spirea. Rejuvenation pruning requires faith. PO Box 32125 RPO Westgate,Maple Ridge, BC. Your previous question to Ask an Expert seems to indicate that you have such a location. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of Advance Local. When to prune. This is what I recommend to clients who wish to keep their rhododendrons from getting too big. The seeds would probably survive composting. Forsythia. All rights reserved (About Us). Gardening season is in full swing and there are lots of questions out there. I have a rhododendron in my front yard that is completely overgrown to the point that it is taller than the lowest point of my roof. – Anne Schmidt, OSU Extension Master Gardener, Q: I have a small water garden and I need to safely dispose of excess salvinia, frogbit and water hyacinth. Red-stemmed dogwoods. Use hand snips if you are worried. Most rhododendrons respond well to pruning. Rejuvenation pruning of Rhododendrons Rhododendron in need of hard pruning In more extreme cases, if your Rhododendron has become overgrown/leggy or you have taken over a new garden that has not been maintained for a while, you will need to utilise a more drastic pruning technique called rejuvenation and the good news is Rhododendrons usually respond well to hard pruning. Follow up this hard pruning with a feed and mulch in spring. By pruning just above viable dormant buds, new healthy growth can be directed to obtain a more desirable shape. Maintenance pruning is the removal of spent flowers and old, dead wood. Rejuvenation pruning consists of cutting down a plant to about 6-18 inches. Community Rules apply to all content you upload or otherwise submit to this site. Rejuvenation Pruning for Azaleas & Rhododendrons Because these are generally slow-growing shrubs, there is often a tendency to plant them too close to other shrubs or obstructions. This major pruning may be a shocking experience for many gardeners. If you look closely at the bark you'll see tiny pink buds everywhere. (Too much nitrogen, for example, causes green growth at the expense of blooms.) The pruning method for each is different. Are you feeding the plants properly? The instructions below are specific to rhododendrons, and will ensure that you prune them such that you increase their beauty and are still able to enjoy them season after season for some time to come. These branches, called primary branches, form the basic scaffold of each shrub. Rejuvenation Pruning. A: It's great that you're taking the trouble to dispose of potentially invasive plants correctly. Pinch off flower clusters (trusses) soon after flowering and prune for size. If in doubt, proceed cautiously, or seek expert advice. Just be careful so you don’t injure the buds below. […] I have also done renovation pruning on rhododendrons. Mock orange. The stumps left after pruning may range in length from 6 to 30 inches. Salvinia (Salvinia minima) is listed as “Quarantine” by the U.S. Department of Agriculture, Noxious and Invasive Plants in Oregon. Pruning, when required, is generally carried out in mid to late spring. Members of the Falconeri series (and 'tree' rhododendrons in general) will not produce new growth from bare wood; rhododendrons in the Thompsonii series also may resent pruning. It would be very unfortunate to get any of these plants into our streams and wetlands. Deciduous shrubs that respond well to rejuvenation pruning include: Lilac. In subsequent years you can continue that process and shape other parts of the plant to a more appropriate form for your landscape. Best case: cut above a cluster of latent buds. The Anah Kruschke rhododendron also has a better tolerance to heat and scorching sun than other varieties. We are talking only of Rejuvenation Pruning of older shrubs. We strongly suggest you consult some good references for a thorough understanding of this beautiful addition to your flower garden. Fortunately, they are actually not too difficult to prune back. Rejuvenation Pruning for Azaleas and Rhododendrons Because these are generally slow growing shrubs, there is often a tendency to plant them too close to other shrubs or obstructions. Some that do not sprout readily from old wood cannot be much improved. Pay special attention to watering. If you have an overgrown shrub that is no longer flowering, try rejuvenation pruning in early spring by cutting all the stems back to the ground. Deutzia. If in doubt, proceed cautiously, or seek expert advice. In the second year after the harsh pruning, many more branch tips will produce flower trusses and by the third year, the shrub should be full and lush, producing numerous and widespread flowers all over. Rejuvenation pruning involves the careful cutting back of each primary branch of the plant’s framework. For rejuvenation pruning, you need to cut each of the primary branches forming the main frame of the plant, carefully. Frogbit (Limnobium spongia) or (Hydrocharis morsus-ranae) is so far unknown in Oregon, but is highly invasive and considered capable of surviving here, Common Frogbit. The Anah Kruschke rhododendron (R. Anah Kruschke) is a cultivated variety that grows up to 5 feet tall and can tolerate winter temperatures down to minus-15 degrees Fahrenheit. I believe more sun is needed so am building a bed for them in a sunny location. This may delay flowering for several years but will result in a more manageable shrub. Rejuvenation pruning calls for dras-tic cuts on old wood Rejuvenation pruning is best used to restore shrubs that have become leggy, overgrown, or otherwise unattractive. This involves bravely making large cuts and significantly reducing the plant size. Rhododendrons are forgiving plants. Bravely make big cuts if rejuvenation is required. Phone: Pruning a rhododendron is normally done for maintenance, shaping, and rejuvenation. Incidentally, Sunset recommends a lightly shaded area rather than full sun for dahlias. […]. Some people use a box of wood shavings or sawdust to put around the tubers to better avoid any rotting. Rejuvenation Pruning for Azaleas and Rhododendrons. Latent buds in action, a cluster of four buds below the cut. The best and safest way to dispose of any invasive plant material is to bag it and put it into the garbage – not compost it. One is the removal of spent flowers (trusses) and any diseased or dead wood. I'd like to prune it way back, but I've heard that it won't bloom for years if we do. This will mean that in years to come - just as the shrub is reaching its full glory, there will be a need to take drastic action by way of cutting down hard. Can I transplant them now? Pruning rhododendrons requires accurate timing. This will mean that in years to come - just as the shrub is reaching its full glory, there will be a need to take drastic action by way of cutting down hard. Such plants fall into RHS Pruning groups 8, 9 and 10 . The second pruning action is for shape. Those are latent buds. The best time to perform the rejuvenation pruning is winter while the plants are dormant. Do this soon after flowering before the new buds get big and set. Do this soon after flowering before the new buds get big and set. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. A rhododendron shrub needs extra care for the first year or two after severe pruning. Most rhodos produce seeds and you can get your rhodo to concentrate on growth by removing the spent flowers. The rejuvenation prune. By pruning just above viable dormant buds, new healthy growth can be directed to obtain a more desirable shape. Photo: properlandscaping.com. Azaleas, which are also members of the Rhododendron genus, are much Registration on or use of this site constitutes acceptance of our User Agreement, Privacy Policy and Cookie Statement, and Your California Privacy Rights (each updated 1/1/20). It will take a couple of years and may decrease blooms, but the plant’s health and appearance will improve substantially. This major pruning may be a shocking experience for many gardeners. This rejuvenation pruning was done at a corner unit where there was a problem with vehicle sight lines. This article, How and When to Prune Rhododendrons, from The American Rhododendron Society has excellent additional information. That's it. Witch hazel. Faith, that nature will do her job. Because these are generally slow growing shrubs, there is often a tendency to plant them too close to other shrubs or obstructions. Photo: properlandscaping.com. 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. Examine their bark and look for tiny pink dots. Then watch. Weigela. Staggered renovation. Others that sprout abundantly should not be opened excessively to light. Rejuvenation pruning consists of cutting down a plant to about 6-18 inches. It’s done by removing the extra branches on a large scale so it’s essential to be sure of this technique before starting. Regular pruning maintains the shrub size and prevents breakage during the winter months by managing the structure. Bluebeard (Caryopteris) -- done annually. Not much to look at right after pruning. Subscribe to OregonLive. james@properlandscaping.com Go slowly, one carefully considered cut at a time. There are three common reasons for pruning rhododendrons: maintenance, shaping, and rejuvenation. Pruning of hardened wood can be done at any time except during periods of freezing weather. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. In rejuvenation pruning, you cut all of the stems down to the ground in one go. Rejuvenation pruning, can be useful to reshape a plant. When spring arrives, after the last frost, dig holes at least a foot deep, place the tuber and fill the hole about a quarter full. As these plants are potentially invasive, I want to know of a safe way to compost them. Sunset Western Garden Book has an excellent chapter on dahlias, and OSU Extension has a good publication about growing dahlias. However, there are some mistakes that you can make if you follow a generic pruning plan. Rejuvenation pruning calls for dras-tic cuts on old wood Rejuvenation pruning is best used to restore shrubs that have become leggy, overgrown, or otherwise unattractive. However, on very old wood, the dormant buds may have atrophied and are not viable. A: Rhododendrons are impressive plants in a landscape. Trimming rhododendrons is typically done for maintenance, shaping, and rejuvenation- as is the case for overgrown plants. I plan on doing some rejuvenation pruning and cutting it back so it is only about 6 feet tall. Q: I love our deep red rhododendron, but it has grown so big that it blocks our front window completely. Deutzia. In rejuvenation pruning, you cut all of the stems down to the ground in one go. This year prune out several selected taller branches by following them to a growth point – a main stem – then removing them. That nature will forgive us for our transgressions. To ask a question, simply go to the OSU Extension website and type in a question and the county where you live. Prune right after the blooming has finished during the summer months of June and July. Save my name, email, and website in this browser for the next time I comment. Now what? I prefer hand pinching. – Multnomah County. Some that do not sprout readily from old wood cannot be much improved. Old rhododendron shrubs of various species come back as fresh and attractive as young plants after they are severely pruned for rejuvenation. Large clumps of tubers on one plant should be divided. There are three pruning actions associated with rhododendrons. – Multnomah County. Here are some questions asked by other gardeners. – Marjorie Neal, OSU Extension Master Gardener. Rhododendrons is a genus of flowering woody shrubs that are enormously popular, at least partly because they are very easy to care for. Water Hyacinth (Eichhoria crassipes) also has “Quarantine” status in Oregon, but there are populations already here so it is capable of surviving here. Most rhododendrons respond well to pruning. Rejuvenation pruning, sometimes called renewal pruning, is used to restore and reinvigorate older shrubs that have “thinned out” over time. The larger-leafed rhododendrons have many dormant buds that can be forced into new growth. OSU Extension faculty and Master Gardeners reply to queries within two business days, usually less. When did you last dig and divide, for example? I am aware that they won't survive in cold temperatures but was not certain if it got cold enough in Portland to kill them off in a compost site. Bluebeard (Caryopteris) -- done annually. By taking action you are doing your part to prevent their spread here in Oregon. All of them have the potential to be highly invasive. Mock orange. In fact, excessive growth may require a heavy pruning. When you cut back a main branch, from these buds will emerge new growth that begins to form the new shrub. Keep the soil evenly moist but not wet or soggy. Fortunately, they are actually not too difficult to prune back. Rejuvenation Pruning. One way of doing rejuvenation pruning is by cutting back the main branches of the plant. One is the removal of spent flowers (trusses) and any diseased or dead wood. Crystal Springs Rhododendron Garden, March 30, 2018. This method will have to be adjusted according to how the basal framework of individual shrubs it set at ground level. It is important to remove the flower stems from the shrub once blooming has stopped. The Art of Pruning: Timing and Techniques Pruning is one of the best things you can do for your shrubs. Get answers from Ask an Expert, an online question-and-answer tool from Oregon State University’s Extension Service. Witch hazel. Pruning them too early will interfere with the budding for this season and pruning them too late will interfere with the next season. If your location does not regularly reach the low 20s freezing weather, you can leave them in the ground until spring. 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. As the shoots grow in the warming weather, add more soil gradually until you reach the ground level.