I planted a couple Nikko blue hydrangeas two years ago, but the flowers
haven't been blue (they were more of a pinkish white). I watered them
with an aluminum sulfate solution this spring and last fall to try to
make the flowers blue this year. Now, I'm considering adding old coffee
grounds to the soil -- Will this counteract the aluminum sulfate, or
will it help to make the flowers blue?

Thanks in advance for any help you can provide.

Suzanne