2002 AAS Flower Winner. Sporting silvery-white blooms with dark purple centers, Tidal Wave Silver is distinct. Unlike other petunias, gardeners can decide the height of the mature plant. Tidal Wave Silver can attain heights of 2 to 3 feet if spaced closely together, about 6 inches, and given support such as a trellis. If plants are spaced a foot apart, the mounded, hedge-like plants will reach 16 to 22 inches. Neither pinching nor pruning is needed for flowers all season. Exhibiting excellent botrytis resistance and rapid recovery in severe weather, Tidal Wave Silver is also adaptable to container culture.