Q.Are used coffee grounds good for hydrangeas?
I was told used coffee grounds are good for hydrangeas, roses and azaleas. I would like to know if it is true. Thank you for your help.

Here are links that have great information.
It can be beneficial, and adding your coffee grounds to your compost is also a great idea.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/diluted-coffee-for-plants.htm
https://www.gardeningknowhow.com/composting/ingredients/coffee-grounds-gardening.htm