Cottondale Woolly Clethra. Bob McCartney of Woodlanders in Aiken, SC, and Tony Avent of Plant Delights, found this plant in the wild in the panhandle of North Florida. In a Clethra cultivar evaluation published in American Nurseryman in 2008, from Longwood Gardens, this selection received the highest marks of any Clethra cultivar. It is native to the Southeast where it makes a suckering colony in moist acidic soils. Its flowers grow in 8-16" spikes or racemes, as the flower spikes will gracefully cascade because of its length. The overall plant can reach 6-8' in height. Grow in full sun to part shade. It is native to the Southeastern U.S.