Hydrangea

About the Hydrangea

Their flower color changes based on soil pH - acidic soil produces blue flowers, alkaline produces pink. This is due to aluminum availability, which is pH-dependent. The color can be changed by adding coffee grounds (acidic) or lime (alkaline). What appear to be petals are actually modified sepals. They are one of the few plants that accumulate aluminum. Over 75 species. They can live 50+ years. Dried hydrangeas retain their color for years. In Japan, they are associated with the rainy season (tsuyu). Some varieties can have both blue and pink flowers on the same plant.