Hydrangeas one of the top ornamental plants in the country - but they have a special place in Cape Cod. Dubbed the signature plant of the area, the naturally acidic soil and mild winters of coastal regions are conducive to the growth and color of this popular perennial. There's even an annual hydrangea festival.

Coming in a variety of colors including blue, green, pink, purple, red and white, depending on the type, the hydrangeas are particularly vivid this summer.

But what determines this variety of colors in one plant? And how come sometimes different blooms on the same plant can be different colors?

Learn more at heraldnews.com.