Hydrangea Serrata Jogasaki. Named after a town in the Izu peninsula of Japan, A great Arnold/Schofield introduction. A Big blowsy hydrangea with fully double sterile flowers surrounding a lovely lace cap centre. For blue flowers make the soil acidic- add elemental sulphur or aluminium sulphate. For pink flowers, alkaline soil-add lime. Full sun to shade with regular water in good soil. To 5' tall and as wide. Prune old wood out in early spring. Water through summer. Deciduous.