If I add alkaline to my rhododendron (like I do to my hydrangeas), will it make the buds (flowers) more purple, similar to what it does to my hydrangea? We live in a northeast coastal community, on the water, and the rhododendron is under two oak trees. It has bloomed profusely the last two years; however, the color is a very pale purple. I'd like to give it a little more color, but not change its color. I know if you add Miracle Grow to a hydrangea, it changes color. That's why I need to know about the rhododendron.
Certified GKH Gardening Expert
Rhododendrons do not have the ability to change their blossom colors like hydrangea. This is unique to hydrangea. Rhododendron prefer a more acid soil and will do better is you provide them with this.