Getting it to bloom

Why won't my Bigleaf Hydrangea 'Nikko Blue' bloom? (and how to make it flower)

Also called Nikko Blue Mophead (Hydrangea macrophylla 'Nikko Blue').

More about bigleaf hydrangea 'nikko blue'

About Bigleaf Hydrangea 'Nikko Blue'

Hydrangea macrophylla 'Nikko Blue' · also called Nikko Blue Mophead · flowering

'Nikko Blue' is a classic mophead bigleaf hydrangea with large rounded flower heads that turn vivid blue in acidic soil or pink in alkaline soil. A vigorous deciduous shrub blooming in summer on old wood, it needs moist, rich soil and shelter, and rewards correct pruning with its signature voluptuous blue domes.

Plant type: flowering

Watch for — No flowers after pruning: Blooms on old wood; pruning in autumn, winter or spring removes the flower buds. Prune only right after flowering, removing spent heads to the next strong buds.

The reasons bigleaf hydrangea 'nikko blue' isn't blooming

Almost every non-blooming bigleaf hydrangea 'nikko blue' traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding bigleaf hydrangea 'nikko blue' a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get bigleaf hydrangea 'nikko blue' to flower

Maximise sun. Give bigleaf hydrangea 'nikko blue' the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for bigleaf hydrangea 'nikko blue' and get the feeding right with the bigleaf hydrangea 'nikko blue' fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Bigleaf Hydrangea 'Nikko Blue' flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full bigleaf hydrangea 'nikko blue' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Bigleaf Hydrangea 'Nikko Blue' blooming — frequently asked questions

Why won't my bigleaf hydrangea 'nikko blue' flower?

Bigleaf Hydrangea 'Nikko Blue' blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make bigleaf hydrangea 'nikko blue' bloom?

Give bigleaf hydrangea 'nikko blue' the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does bigleaf hydrangea 'nikko blue' normally bloom?