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Rhododendron Questions
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Date Posted: Thu, May 08 - 11:14 pm
- I have an established rhododendron and a couple of questions 1. Some leaves tern yellow and die and fall off 2. Others show yellowing but remain 3. New shoots form at the base but die never to mature 4 is there any way to encourage new growth on the old branches
- Thanks for reaching out with your rhododendron questions! You’ve made some great observations, and your plant is definitely trying to tell you something. Here are a few possible explanations and tips based on what you described: Yellowing and Leaf Drop: Some yellowing and leaf drop is normal, especially for older inner leaves. However, widespread or early-season yellowing in Richmond can also point to stress from heat or underlying root issues, particularly since rhododendrons are naturally cool-climate, understory plants. Our warm springs and hot summers can make them more susceptible to systemic diseases or environmental stress. Persistent Yellow Leaves: This could be a sign of sun stress—rhododendrons prefer morning sun with dappled afternoon shade. Too much direct, hot afternoon sun can cause the kind of yellowing you're seeing. Poor drainage or soil that’s too alkaline can also cause nutrient uptake issues, leading to chlorosis (leaf yellowing). New Shoots Dying Back: When new shoots at the base fail to mature, it often points to root zone stress, such as poor drainage, fungal root diseases, or heat stress. Check that mulch isn't piled too high against the base and that the soil is staying moist but not soggy. Encouraging New Growth on Old Branches: Yes! Light pruning in early spring, just after flowering, can stimulate new growth. Avoid heavy pruning all at once; instead, gradually thin out leggy or unproductive branches over time. Make cuts just above a healthy bud or leaf whorl to encourage branching. Good luck with your rhododendron!
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Rhododendrons
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Date Posted: Wed, Apr 26 - 3:24 pm
- I have several rhododendron bushes in my front yard. They usually bloom once a year. I would like them to bloom more often. I don’t understand why one of the bushes leaves turned completely brown and died. Will this bush come back? Should I pull it up? What can I do?
- Hello there, Rhododendrons bloom once a year, in late winter into spring depending on variety. You could add other varieties with different bloom times to extend the show. You could also add some azaleas (which are in the same family). Some of those do bloom twice a year. The variety Encore comes to mind. As for the browning of the leaves and leaf drop, a number of issues could be causing that. Poor drainage, leaf burn from too much sun, winter burn, nutrient deficiency. It's difficult to diagnose in this manner. But you can try this practice - if you give the plant plenty of time to begin spring growth—waiting until late spring—you can then scratch the bark on dead-looking branches with your fingernail. If there is green wood underneath, the branch is still alive. Leave it be and it may very well leaf out. If it's brown underneath, the branch is dead and you can prune it off. Also, you can visit one of the Master Gardeners that man the desk at your local library. Call the library to see when the Help Desk is in session. Any information you have about the plants-photos, samples, will be helpful. But sometimes you need to assess the planting environment to narrow down the problem. You can also get a soil testing kit and the results will help you improve the nutrients and condition of your soil to ensure future plant health.
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Yellow Spots on Rhododendron Leaves
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Date Posted: Wed, Aug 18 - 2:01 pm
- My large rhododendrons have some yellow specked leaves. Been watering every other day. What are you suggestions
- Hello! Thanks for your question. Given our recent warm and humid weather conditions, the problem you are having with your rhododendron is certainly not uncommon. I suspect your plant has a fungal condition called leaf septoria (yellow leaf spot). It sounds as though the condition on your plants is not widespread at this point and there are a few steps you should take to rid your plants of this fungus. First, remove the affected leaves to get rid of as many fungal spores as possible. Secondly, take away any fallen leaves from under the plant and keep the area clean. Discard all removed leaves in the trash (not compost). Mulch the area under your rhododendrons; this helps prevent spores from spreading. It will also help retain/absorb the water when you are watering the plants, and reduce splash upwards. And when you water, it’s best to use a soaker hose at the base of your plants, versus overhead watering. Watering overhead and watering in the evening can increase fungal disease development on these plants. You can also apply a simple, all natural spray solution consisting of the following: one quart of water in spray bottle with 1 teaspoon of baking soda; add 1/2 teaspoon of canola oil and a few drops of dish soap; shake the solution well and spray on the plants. Good luck with this - improved weather conditions in the coming weeks hopefully will help as well! Let us know if you have further questions. Thanks! And of course keep a close eye on your other grow bags with your other vegetables for any similar signs. Good luck with your garden, and wishing you a strong yield!