For now, be patient. By Kevin Wilcox  – Rhododendrons have had a tough year. The damage was principally to the leaves and not stems of the plants, so when it is time for new growth to emerge, it will. It only takes a little practice, you soon pick up the knack without causing any damage. Kevin Wilcox is the owner of Silver Spring Nursery in Bloomfield, and is a member of the CHS Board. Most rhododendrons will begin to grow in the next few weeks, showing you where they may need to be pruned, or that they don’t need to be pruned at all. There are more than 900 species in the Rhododendron genus, which vary greatly. Last but not least, we had many days with bright sunlight that reflected off the snow and burned the leaves of rhododendrons. It is not worth letting the seedheads fill up and develop as you are unlikely to be trying to breed your own from seed. Those buds are still alive. Rhododendron are often planted in afternoon shade so hot summer sun won’t burn the leaves. To me it is therapeutic on a warm spring afternoon to be helping channel the natural energy into plants that have given so much pleasure already. If you look closely on the next picture you will see that at either side of the seed spikes there are leaf buds. Some of the most common dangers to your rhododendron include aphids, root rot and Japanese beetles. You may also find flower buds dried and brown in their center, but if you’re lucky, they will still be green. Let’s assume you are seeing damage from stem borers. If you feel the need to fertilize, do so sparingly and with something organic instead of the blue colored liquid soluble fertilizers. Dark brown dead roots= Phytophthora caused by poor drainage. It usually attacks plants that are under stress due to drought, too much sun or late frosts. My Rhododendron Is Losing Leaves and Is Crispy. Rhododendrons (including deciduous azaleas) may be attacked by several diseases, causing unsightly foliage or a lack of flowers. Required fields are marked *. Look at the bark on a stem or main branch of many rhododendrons and you will see tiny buds, little pink dots about the size of a pinhead that pepper the surface of older branches. It has lost all but perhaps 10 leaves which are producing flowers. These plants are therefore more susceptible to winter leaf burn because the sun reflecting off the snow reaches foliage that is not usually exposed to such intense light, resulting in a light to medium browning of their leaves, especially on the south facing side. Here you can see the seeds have been removed and added to the compost heap. Save my name, email, and website in this browser for the next time I comment. Perhaps a good book will help the beginner get an overview. The damage can be traced to one or more of three problems: heat stress from last summer, infestations of Rhododendron stem borers, and/or our harsh winter weather from these past few months. Your email address will not be published. Failing that there is membership of the RHS specialist section The Rhododendron, Camellia & Magnolia Group. Those plants with the highest degree of stress are the plants that are now dead. The evergreen leafed species of Rhododendron are just that, they remain green throughout the winter months. Rhododendrons are lovely plants with enchanting blooms that range from dark red to lavender. Look out for plants with the Award of Garden Merit including the following Lepidote species Augustinii, Edgeworthii, Keiskei, Racemosum and Yunnanense. The former is a naturally occurring phenomenon that takes place as the result of changing weather patterns and doesn't necessarily indicate a dead plant. Keep the area weed free. A fungus called phytophthera takes hold if the roots are in overly damp conditions. I find the canopy of Rhododendron leaves works well keeping weeds down. In some cases, plants with a single branch of browned leaves may have been damaged by the weight of snow, which could bend the stems enough to cause vascular damage. And this past winter we had it all. More rhododendrons are killed by waterlogging and poor drainage than any other cause. Agricultural Experiment Station, either in Windsor, or New Haven. It can be a long job on a large Rhododendron but I pinch out the seedheads to divert energy back to the shrub and give the leaf buds space to develop. Fungicide application in late spring and summer help the shrub to recover. Pinching the often sticky seedsheads, I give a twist to break the stem just above the new leaf joint. Is my Rhododendron dead ...or not? Charlotta Wasteson / Flickr Creative Commons. The easiest style of pruning is trimming off any dead or dying parts of your rhododendron with pruning shears. The other cause for dead branches on an otherwise healthy looking plant could be an infestation of Rhododendron stem borers. You can find them at www.ct.gov/caes/site/default.asp. Soon the display of colourful Rhododendrons will falter and be over for another year. It can be a long job on a large Rhododendron but I pinch out the seedheads to divert energy back to the shrub and give the leaf buds space to develop. Let’s assume you are seeing damage from stem borers. I still like the leaf colours, textures and shapes and Rhododendrons are easy to for. www.rhodogroup-rhs.org/ This society controls ‘The International Rhododendron Register and Checklist’ of the named 29,000 +varieties, cultivars and group names. So any energy put into the seedheads is energy lost from next years plant and flowers. Use fungicides and follow the directions in the bottle. The two primary reasons that rhododendron leaves turn brown are cold weather and rhododendron wilt. Failing to deadhead is not to say leaving the shrub to its own devices will be a failure but as we are growing for ornamental purposes every bit to care helps. And, don’t forget about your rhododendrons when the weather turns hot and dry; if nature doesn’t provide any rain, a little bit of water each week will reduce their stress. It is during July and August when rhododendron are finishing their yearly growth, forming flower buds for spring, and getting ready for winter. Generally there are two leaf buds for each dead flower. Scrape away some of the stem to see if there is any green healthy tissue before giving up on it completely. Winter’s colder temperatures keep the leaves’ green chloroplasts from turning brown even after they are damaged. In the wild Rhododendrons manage quite nicely thank you without this TLC. Rhododendrons are shallow rooted so they like a drink and an occasional feed of ericaceous fertiliser. The adult borer is a moth, which lays eggs typically at the base of the shrub or at the bottom of the v-crotch of two branches. To test this theory, you can check the stems to see if they look full and plump, or wrinkled and dry. Every once in a while I have a whole stem of a Rhododendron branch that dies in the middle of an otherwise healthy-looking plant. So, before you prune or hack your rhodies to the ground, try to assess the problem. If you look closely on the next picture you will see that at either side of the seed spikes there are leaf buds. The excess of heat may not have prevented these shrubs from completing their biological preparedness for winter, but it did ensure that many plants started winter with unresolved stress-related problems. The latter is … Once you have the insect inside the stem, there is no chemical control, but you can snake a thin piece of wire into the entry hole and skewer the insect. Cold temperatures resulted in the snow staying around and not melting. E-mail: office@cthort.org. (NOT the … There are some good tips to get a great show next spring, it is never to early too start. On the above photo the petals have just fallen and the long,  tubular seedheads are just beginning to form. I hear some of you say but it is the natural ericaceous medium for Rhododendrons). Generally there are two leaf buds for each dead flower. Box 330966 It has lost all but perhaps 10 leaves which are producing flowers. West Hartford, CT 06133-0966, Phone: 860-529-8713 Blooming rhododendrons look like colorful, puffy clouds floating through the landscape, so when they don’t deliver, not only is it a huge disappointment, but a cause for concern for many gardeners. Cut off dead wood and flowers for a low-maintenance prune. This past year we saw all four extremes, with one after another increasing the stress on our plants.