Adding coffee grounds to hydrangea soil?

Question

I have a hydrangea that I just bought and planted yesterday. Its in a 10 gallon pot and I'm keeping it on my patio. The flowers are kinda mauve in color. I want to make them blue in the future. How much coffee grounds should I add and how often do hydrangeas bloom. I'm in zone 9 by the way.

Thanks

Thanks so much for the advice. I currently have the hydrangea on the patio where it receives morning sun. By noon the flowers and leaves are a somewhat limp. I'm concerned maybe the heat is doing this. I have the pot in a part of the patio where its not in direct sunlight but it is warm. Its 82 degree's outside but feels much hotter due to humidity.

Answer 1

Add as much coffee grounds (tea bags too) as you like. Won't hurt them. Epsom salts also good for blue.