How to Fertilize hydrangea 'Shirotae'?
Hydrangea feed in spring and again early summer

hydrangea 'Shirotae' · Hydrangea serrata 'Shirotae'
Grow in moist but well-drained, humus rich soil, in a lightly shaded spot with shelter from cold, drying winds. Mulch annually in spring. See shrubby hydrangea cultivation for more detailed advice
Hydrangea feed in spring and again early summer