Don Smetana of Washington registered this sport of H. 'Love Pat' in 1994. Forming a large size (19 inches high) mound, this cultivar is known for its thick, heavily corrugated and cupped foliage. 'Kit Kat' has a chartreuse colored leaf center when it emerges in the spring which turns to blue-green by mid-summer. It produces dense clusters of near white flowers from late June into July.