Rhododendron

Question

Mine have brown on the ends, even the new growth has brown on the ends. Some of the lower leaves are turning all brown and falling off.

Answer 1

Your plant could be suffering from pest damage, fungus or even sun damage.
These articles will help you access the plant.

https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm

http://cru.cahe.wsu.edu/CEPublications/eb1229/eb1229.pdf