One of the biggest surprises and sometimes disappointment is when a flower you expect to be blue emerges pink. This is pure science - acidic soil will produce the blue to purple tones while neutral to alkaline soil will yield pink flowers. 'Outer Banks' is a blue lacecap hydrangea when grown in the acidic soil that is typical of the maritime Pacific NW but may produce pink flowers when grown in an alkaline potting soil. Part of the Seaside Serenade series of hydrangeas, this variety grows roughly four feet tall and wide at maturity, and has a higher resistance to scorching on hot summer days. Regardless of the color, bees and butterflies love the small inner flowers that are surrounded by blue (or pink) bracts. Prune 'Outer Banks' in the fall (or late winter) to keep the shrub more compact.