Adding sulfur for color
I have very alkaline soil, so naturally, most of my hydrangeas are pink. My neighbor across the street has blue. I find it amazing that our soil can be so different.
In any case, she likes the pink and I like the blue (naturally). So I decided to try the garden sulfur I had on hand and measured according to the directions on the package. I scratched it in. After a few rains, I was delighted when the flowers turned a light purple/bluish color. My question is: if I decide to make them even more purple and blue, how often do you use the sulfur? I don't want to harm the plant.