My rhododendron has only a few blooms this year. when I bought it last year it was full of blooms. I potted the plant into a larger container. Watered well and mulched the top to help with retaining the moisture. Watered with rain water throughout the year and was hoping for the same spectacular flowers this year. Sadly, there are only a few flowers on the plant. The leaves look healthy after treating with a solution for Whitley, which seemed to cover the leaves soon after I bought the plant. It stands against a west facing fence. Gets sun in the morning right up until after midday. How do I deadhead correctly to ensure a mass of blooms next year? What am I doing wrong?
There are several things that might be causing this. As the leaves look
healthy, it is likely a nutrient issue. Try applying some bone meal or
phosphorous rich fertilizer to the plant.
This article will have some other possibilities: