Let's Dance® Rhythmic Blue® Reblooming Hydrangea

Geometric florets pack tightly into mopheads that shift to a rich blue more readily than most bigleaf hydrangeas. Hydrangea macrophylla Let's Dance® Rhythmic Blue® 'SMHMES1' grows 3 to 4 feet tall and wide in part shade, hardy from Zone 5 through Zone 9. The florets are unusually angular, which gives the flower head a tighter, more structured look than a rounded mophead. It reblooms, flowering on old and new wood. Bigleaf hydrangeas change color with soil pH. Acidic soil below about 6.0 gives blue, alkaline above 7.0 gives pink, and the range between produces purple or a mix of pink and blue on the same plant. White varieties stay white. Aluminum sulfate pushes flowers toward blue and garden lime pushes them toward pink, and either takes a season to show. Older bigleaf hydrangeas flower only on old wood, meaning buds set in late summer for the following year, so a hard winter or a late frost could cost a whole season. Most varieties now bloom on both old and new wood, though the second round is lighter than the first. Prune in summer after the first flowering and no later than August, since cutting in fall or early spring removes the buds that carry the heaviest bloom. Dead stems can come out in spring, once new growth shows which ones are dead. Give it morning sun and afternoon shade with steady moisture.