離 Hydrangea Color Magic Comes from the Soil! 離 Did you know hydrangea flowers dont choose their color? Its actually the pH of the soil that decides! Acidic soil pH below 5.5: blooms turn deep blue Neutral soil around pH 6.57: they become purple-pink Alkaline soil pH above 7: youll see bright pink flowers Gardeners tip: Want blue? Mix in garden sulfur. Prefer pink? Try some lime. Nature will do the rest just watch and enjoy!