Hydrangea macrophylla 'NIKKO BLUE' mop-head hydrangea

Nikko Blue is another reliable and hardy (for zone 6) mop-head hydrangea variety. It produces large, globular inflorescences composed of small, sky blue flowers which emerge pale bluegreen to soft yellow. It flowers on previous year's growth so no trimming is recommended in spring. If you need to shape or rejuvenate the plant do so in midsummer. The leaves are deciduous, medium to dark green, glossy, and heavily serrated at margins. It grows moderately into a sizeable shrub which under ideal conditions may slightly exceed 1.5m which makes it a great choice for informal, flowering hedge.

As its blue colour is determined by the soil acidity we strongly recommend using solely peat-based substrate for ericaceous plants or blueberries of low pH value. Grow it in fertile, always moist but well-drained soil. Never let the soil dry out especially in the first year before it gets established. The name hydrangea suggests it will need a lot of water but dislikes standing water in heavy clay soil. It will love part shade, shade, or filtered sunlight. In colder regions it should be protected with fir branches in harsh winters. Good mulch is advisable at all times. Fully hardy to about -23°C (USDA zone 6).

Last update 18-12-2019