What’s Behind Rhododendron Producing Yellow Leaves?

Asked September 28, 2020, 2:24 PM EDT

I planted two large Rhododendrons this summer – about 3-4’ tall. They are within 10 feet of each other. One is now dropping bright yellow leaves (100% yellow) from the bottom of the bush. See attached photograph. Is this an indication of too much or too little watering? Or are cooler temperatures these past few weeks just creating this process? The other is not doing this. See photos. Appreciate any insights. George from Crownsville

Anne Arundel County Maryland

1 Response

We think this looks like normal leaf shedding on the rhododendron. Monitor the shrubs and you can send us more photos if you notice additional symptoms.

Make sure mulch is no thicker than several inches and away from the base of the trunk. Check the soil moisture for new plants about once a seek and especially during dry periods and water deeply if needed. Move the mulch aside and check the soil moisture by probing with a screwdriver about 6 inches deep and feel with your finger. Soil should be damp to the touch. Let the soil dry before watering again. Check the soil moisture in the autumn months all the way up until the ground freezes. It can take about two years for new plants to establish their root systems.
See watering guidelines. https://extension.umd.edu/hgic/topics/watering-trees-and-shrubs