Which flowering plant is known to react to pH levels with color variation?

Hydrangeas are well-known for their ability to change color based on the pH levels of the soil in which they are planted. When the soil is more acidic, hydrangeas tend to produce blue flowers, while more alkaline soil often results in pink flowers. This phenomenon is due to the presence of aluminum ions in the soil; in acidic conditions, aluminum is more available for uptake by the plant, influencing the color of the flowers.

Roses, tulips, and sunflowers do not exhibit this pH-related color change in the same way. They typically maintain consistent flower colors regardless of soil pH. Roses, for instance, are bred for specific colors, and their blooms do not change color based on soil conditions. Tulips have a stable color palette as well, and sunflowers are primarily known for their vibrant yellow hue, which is unaffected by soil pH. This unique characteristic of hydrangeas makes them particularly interesting in gardening and floral design, offering opportunities for visual variation based on growing conditions.