Blue Billow Hydrangea

Plant in spring or fall in moist, well-drained soil in partial shade, spacing 3–4 feet apart. Blue Billow is a compact lacecap hydrangea with beautiful, flat-topped flower clusters featuring blue fertile florets surrounded by larger, white sterile florets. It is notably cold-hardy for a bigleaf hydrangea. Incorporate compost and water well. Mulch generously to protect buds through cold winters.

Prune only dead wood in early spring — removing live stems reduces flowering. Keep soil consistently moist. Flower color is pH-dependent: acidic soils produce blue, alkaline soils produce pink. Add aluminum sulfate to encourage blue color in neutral soils. Fertilize lightly in spring. The lacecap flower form is more refined and elegant than mophead types. Blue Billow's cold hardiness makes it more reliable than many bigleaf hydrangeas in northern gardens.