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. In rejuvenation pruning, you cut all of the stems down to the ground in one go. The second pruning action is for shape. This involves bravely making large cuts and significantly reducing the plant size. A: Rhododendrons are impressive plants in a landscape. Plants that respond well to rejuvenation include, forsythia, lilac, and spirea. The second type of rejuvenation pruning involves cutting off the trunk of the rhododendron shrub to 6 to 12 inches from the soil. – Multnomah County. Perhaps there are other factors causing the low bloom. Rejuvenation pruning. Prune right after the blooming has finished during the summer months of June and July. That nature will forgive us for our transgressions. 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. Please support high-quality local journalism. This works because rhodos are special. Photo: properlandscaping.com. With a rhododendron or azalea that lives up to their reputations as the … The larger-leafed rhododendrons have many dormant buds that can be forced into new growth. Unlike many shrubs, Rhododendrons seldom require pruning, although they may benefit from an occasional maintenance trim. 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. When pruned properly, the result is a fuller plant that produces an abundance of flowers. […] I have also done renovation pruning on rhododendrons. For rejuvenation pruning, you need to cut each of the primary branches forming the main frame of the plant, carefully. – 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. Many rhododendron spe-cies and hybrids can be severely pruned and come back as good as new. This will shorten the plant and enable you to see out your window. Rhododendrons is a genus of flowering woody shrubs that are enormously popular, at least partly because they are very easy to care for. Rejuvenation pruning consists of cutting down a plant to about 6-18 inches. Photo: properlandscaping.com. Because these are generally slow growing shrubs, there is often a tendency to plant them too close to other shrubs or obstructions. Sunset Western Garden Book has an excellent chapter on dahlias, and OSU Extension has a good publication about growing dahlias. If not, when? Rejuvenation pruning, can be useful to reshape a plant. 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. This is what I recommend to clients who wish to keep their rhododendrons from getting too big. That's it. It’s done by removing the extra branches on a large scale so it’s essential to be sure of this technique before starting. The rejuvenation prune. 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. The larger-leafed rhododendrons have many dormant buds that can be forced into new growth. Most rhodos produce seeds and you can get your rhodo to concentrate on growth by removing the spent flowers. 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. Use hand snips if you are worried. This major pruning may be a shocking experience for many gardeners. Done every three to five years, this extreme method of pruning can indeed rejuvenate an overgrown or misshapen shrub, just as the name implies. Pruning rhododendrons is not that different from pruning other types of flowers. This makes neat little mounds of twigs that will explode with new growth come spring. Deciduous shrubs that respond well to rejuvenation pruning include: Lilac. 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. It would be very unfortunate to get any of these plants into our streams and wetlands. Forsythia. This growth may need subsequent thinning out to select the strongest, best placed shoots. If in doubt, proceed cautiously, or seek expert advice. Others that sprout abundantly should not be opened excessively to light. Email: 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. Salvinia (Salvinia minima) is listed as “Quarantine” by the U.S. Department of Agriculture, Noxious and Invasive Plants in Oregon. Not much to look at right after pruning. We are talking only of Rejuvenation Pruning of older shrubs. 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. Red-stemmed dogwoods. If you look closely at the bark you'll see tiny pink buds everywhere. Once established, most evergreen shrubs are fairly low maintenance and need little or no regular pruning. Can I transplant them now? This method will have to be adjusted according to how the basal framework of individual shrubs it set at ground level. Deutzia. Remember! Take your time and prune over a couple of years. Somewhere down the road we will be rewarded with a less unruly plant. Pruning large rhododendrons can seem like an overwhelming undertaking, but it doesn’t need to be. 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. It is important to remove the flower stems from the shrub once blooming has stopped. Faith, that nature will do her job. Pruning a rhododendron is normally done for maintenance, shaping, and rejuvenation. There are three pruning actions associated with rhododendrons. Staggered renovation. Weigela. But what if your rhodo is too big? These branches, called primary branches, form the basic scaffold of each shrub. Some shrubs will have a single main stem from which the framework branches grow. What this translates to is after the frost in fall when the plants die back. Plants that respond well to rejuvenation include, forsythia, lilac, and spirea. Note to readers: if you purchase something through one of our affiliate links we may earn a commission. Examine their bark and look for tiny pink dots. Drivers couldn’t see properly when turning. Rejuvenation pruning works on rhododendrons because they produce small buds all over the surface of branches, even the old ones. 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. Best case: cut above a cluster of latent buds. Bluebeard (Caryopteris) -- done annually. Rejuvenation pruning, sometimes called renewal pruning, is used to restore and reinvigorate older shrubs that have “thinned out” over time. Rejuvenation pruning consists of cutting down a plant to about 6-18 inches. Do this soon after flowering before the new buds get big and set. Fortunately, they are actually not too difficult to prune back. Spiraea. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. Maintenance pruning is the removal of spent flowers and old, dead wood. Large clumps of tubers on one plant should be divided. – 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. Rejuvenation pruning, also called renewal pruning, involves cutting some types of shrubs almost down to the ground, leaving only 6 to 24 inches. 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. By taking action you are doing your part to prevent their spread here in Oregon. – Josephine County, A: You must wait until the current plantings have “rebuilt” the necessary strength in the tuberous roots to bloom again. – Multnomah County. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. If your plant has become quite leggy with old wood, then what you’ll need to do is rejuvenation pruning. What’s yours? Kym Pokorny | For The Oregonian/OregonLive. All of them have the potential to be highly invasive. Rejuvenation Pruning. Mock orange. Others that sprout abundantly should not be opened excessively to light. Rejuvenation Pruning. Old rhododendron shrubs of various species come back as fresh and attractive as young plants after they are severely pruned for rejuvenation. Community Rules apply to all content you upload or otherwise submit to this site. This article, How and When to Prune Rhododendrons, from The American Rhododendron Society has excellent additional information. Pruning, when required, is generally carried out in mid to late spring. Fortunately, they are actually not too difficult to prune back. A: It's great that you're taking the trouble to dispose of potentially invasive plants correctly. Phone: Flowering quince. However, there are some mistakes that you can make if you follow a generic pruning plan. Regular pruning maintains the shrub size and prevents breakage during the winter months by managing the structure. Subscribe to OregonLive. The pruning method for each is different. Incidentally, Sunset recommends a lightly shaded area rather than full sun for dahlias. Crystal Springs Rhododendron Garden, March 30, 2018. 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). All rights reserved (About Us). Latent buds in action, a cluster of four buds below the cut. Prune your large rhododendron right after it finishes blooming. The main goal of rejuvenation pruning is height reduction, and in many cases, plants may be reduced in height by 75 to 90 percent. Q: I love our deep red rhododendron, but it has grown so big that it blocks our front window completely. 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. We strongly suggest you consult some good references for a thorough understanding of this beautiful addition to your flower garden. When you cut back a main branch, from these buds will emerge new growth that begins to form the new shrub. The best time to perform the rejuvenation pruning is winter while the plants are dormant. Spiraea. 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. When did you last dig and divide, for example? You can consult any good source of information on perennials to find out how this is done and when. First, the ideal time to do undertake rejuvenation pruning is not after flowering (that’s when you do light pruning), but … Save my name, email, and website in this browser for the next time I comment. This makes neat little mounds of twigs that will explode with new growth come spring. Some that do not sprout readily from old wood cannot be much improved. 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. This may delay flowering for several years but will result in a more manageable shrub. PO Box 32125 RPO Westgate,Maple Ridge, BC. You will be removing all old wood, and the plant will begin producing new juvenile stems and new foliage shortly after pruning. 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. Always aim to cut above these buds. Then watch. Pay special attention to watering. Pruning of hardened wood can be done at any time except during periods of freezing weather. Red-stemmed dogwoods. © 2020 Advance Local Media LLC. Pruning rhododendrons requires accurate timing. It even creates more flowers as the shrub redirects its energy into flower production rather than overgrowth. Rejuvenation pruning removes most of the branches of the plant, initi- Your previous question to Ask an Expert seems to indicate that you have such a location. Many rhododendron spe-cies and hybrids can be severely pruned and come back as good as new. Rejuvenation pruning, can be useful to reshape a plant. – Marjorie Neal, OSU Extension Master Gardener. Gardening season is in full swing and there are lots of questions out there. 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. The stumps left after pruning may range in length from 6 to 30 inches. Deutzia. 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. Cutting back a rhododendron leaves little more than stubs… but don’t worry, it will grow back. Get answers from Ask an Expert, an online question-and-answer tool from Oregon State University’s Extension Service. Photo: properlandscaping.com. 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