Getting it to bloom

Why won't my Mountain Hydrangea 'Bluebird' bloom? (and how to make it flower)

Also called Lacecap Mountain Hydrangea (Hydrangea serrata 'Bluebird').

More about mountain hydrangea 'bluebird'

About Mountain Hydrangea 'Bluebird'

Hydrangea serrata 'Bluebird' · also called Lacecap Mountain Hydrangea · flowering

'Bluebird' is a refined, cold-hardy mountain hydrangea bearing flat lacecap flowers, a ring of showy sterile florets around tiny fertile ones that turn vivid blue in acidic soil or pink in alkaline. Compact and dainty with red-tinged autumn foliage, it blooms on old wood, prefers dappled shade, and resists frost better than bigleaf hydrangeas.

Plant type: flowering

Watch for — Flower color won't turn blue (or stays pink): Color reflects soil pH and aluminum availability, not the cultivar. Lower pH with sulfur/aluminum sulfate for blue; raise it with lime for pink. Container mixes and concrete leaching can skew results.

The reasons mountain hydrangea 'bluebird' isn't blooming

Almost every non-blooming mountain hydrangea 'bluebird' 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 mountain hydrangea 'bluebird' 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 mountain hydrangea 'bluebird' to flower

Maximise sun. Give mountain hydrangea 'bluebird' 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 mountain hydrangea 'bluebird' and get the feeding right with the mountain hydrangea 'bluebird' 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

Mountain Hydrangea 'Bluebird' 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 mountain hydrangea 'bluebird' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Mountain Hydrangea 'Bluebird' blooming — frequently asked questions

Why won't my mountain hydrangea 'bluebird' flower?

Mountain Hydrangea 'Bluebird' 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 mountain hydrangea 'bluebird' bloom?

Give mountain hydrangea 'bluebird' 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 mountain hydrangea 'bluebird' normally bloom?