Getting it to bloom

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

Also called mophead hydrangea, lacecap hydrangea, bigleaf hydrangea (Hydrangea macrophylla).

About Hydrangea

Hydrangea macrophylla · also called mophead hydrangea, lacecap hydrangea · flowering

Hydrangea is a deciduous shrub with large rounded (mophead) or flat (lacecap) flower heads from midsummer to autumn. Flower colour on bigleaf types depends on soil pH — acidic gives blue, alkaline gives pink. Toxic to pets.

Bigleaf hydrangea (Hydrangea macrophylla) is native to China and Japan; it is the species famous for soil-driven flower-color change in blue/pink cultivars.

Plant type: flowering

Watch for — No flowers: Pruned at the wrong time — bigleafs flower on old wood, panicle types flower on new wood.

Sources: rhs.org.uk, missouribotanicalgarden.org, rhs.org.uk

The reasons hydrangea isn't blooming

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

Pruned at the wrong time — cutting a mophead/lacecap in autumn or spring removes the very buds that would have flowered.
Flower buds killed by a late spring frost on early-leafing stems.
Too little sun — most flowering shrubs need several hours of direct light to bloom well.
Excess nitrogen (often from lawn feed nearby) pushing leafy growth over flowers.
Drought or root stress at the bud-forming time, so buds abort.

Pruning hydrangea at the wrong time and cutting off the wood that carries the flowers — the most common reason a healthy shrub never blooms.

The fix — how to get hydrangea to flower

Prune at the correct time. Know your hydrangea type: prune mophead/lacecap types only just after flowering (or barely at all), and only cut paniculata/arborescens types hard in late winter.
Protect the buds. Leave old stems over winter for frost protection and avoid cutting until the threat of hard frost has passed.
Give it sun and the right feed. Site it in good light and use a balanced or higher-potassium feed — not a high-nitrogen one — to favour flowers.
Let it mature. Give a young or hard-pruned plant a year or two to build flowering wood before expecting a full display.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for hydrangea and get the feeding right with the hydrangea 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

Hydrangea flowers in its established season — typically late spring through summer for a mature, correctly pruned plant — with the display improving year on year once it settles.

Post-bloom care so it flowers again

Deadhead (or leave seed heads where they protect buds), feed after flowering, and time any pruning to the plant's wood type so next year's flowers are not cut away.

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

Hydrangea blooming — frequently asked questions

Why won't my hydrangea flower?

Hydrangea flowers on wood from a specific year depending on type — many bloom on LAST year's stems, so flowering depends on not cutting off the buds and protecting them from late frost. The most common reason it is not happening: Pruned at the wrong time — cutting a mophead/lacecap in autumn or spring removes the very buds that would have flowered.

How do I make hydrangea bloom?

Know your hydrangea type: prune mophead/lacecap types only just after flowering (or barely at all), and only cut paniculata/arborescens types hard in late winter. Leave old stems over winter for frost protection and avoid cutting until the threat of hard frost has passed.

When does hydrangea normally bloom?