Rhododendron not flowering

Question

In Glasgow, Scotland, with clay soil. Moist and partial shade. For the past 2 years my rhododendron bush has not flowered, but the bush itself is flourishing. I had transplanted it to a different area of my garden, on the year before it stopped flowering.

Answer 1

It's likely the soil. If soil has too much nitrogen, it will encourage more foliage growth as opposed to flowering, which needs more phosphorus. Use a "bloom booster" fertilizer or add some bone meal to the soil to help add some phosphorus.