Wee Bit Grumpy® Reblooming Bigleaf Hydrangea

Deep moody purple-blue flowers, saturated enough to read almost black in low light, on a dwarf bigleaf hydrangea 1 to 2 feet tall. Hydrangea macrophylla Wee Bit Grumpy® 'Stragrum' spreads 2 to 3 feet in part shade, hardy from Zone 5 through Zone 9. That depth of color is unusual in a hydrangea, where most run toward clear pinks and blues. 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. Dark flowers show best against a light background or where afternoon light catches them. It needs no pruning beyond dead wood.