Last year my blue Hydragnea flowers were more pink and green than blue. I read to fertilize it and that should help but what fertilizer should I use?
What Is the Best Fertilizer to Make My Blue Hydrangea Rebloom Blue?
Certified GKH Gardening Expert
This article will also help: https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/change-hydrangea-color.htm
blue(nico) hydrangeas can be made more blue by using aluminum sulphate as prescrkibed by the manufacturer to bring ten PH down to the 4.0 to 5.5 range. If you do not soil test begin as soon as yu start to get blossoms and add al/so4 every 2 weeks