Why Is My Hydrangea Not Blooming?
Work through the causes in order, starting with the two that explain most cases.
Why is my hydrangea not blooming? Penn State Extension sums it up: usually because of poor pruning, by people or by the weather. Both come down to the same thing. Most bigleaf hydrangeas flower on buds that formed the summer before, and anything that removes those buds removes the flowers.
If your plant is a panicle or smooth hydrangea, which bloom on new wood, the cause is more likely shade, fertilizer, drought or a young plant. The checklist below covers both.
Hydrangea not blooming, the usual causes: 1. Pruned at the wrong time (bigleaf cut between fall and early spring). 2. Winter-killed buds on old-wood bigleaf. 3. A gift or florist hydrangea that is not winter hardy. 4. Too much shade. 5. Too much nitrogen. 6. Drought. 7. A plant still establishing in its first season.
Think it was the pruning? See How to Prune Hydrangeas in Canada for when to cut each type.
First, Which Hydrangea Is It?
| Type | Flower Heads | Blooms On |
|---|---|---|
| Bigleaf | Round mopheads or flat lacecaps; blue, pink or white | Old wood (rebloomers: old and new) |
| Panicle | Cone-shaped, white aging to pink | New wood |
| Smooth | Round, white (e.g. Annabelle) | New wood |
| Oakleaf | Cone-shaped; oak-shaped leaves | Old wood |
If it blooms on new wood and still does not flower, skip to shade, fertilizer and water below.
1. Pruned at the Wrong Time
Penn State Extension: if you cut back a hydrangea that blooms on old wood between autumn and early spring, you have trimmed off all the future flowers. The University of Illinois says old-wood hydrangeas start forming next year’s buds in August and September, so any pruning should happen right after flowering and by August 1. The University of Massachusetts adds that spring is the time only to remove stems that are clearly dead.
2. Winter Killed the Buds
The University of Massachusetts lists low temperatures, fluctuating temperatures and late frost or freeze as what kills bigleaf buds, and notes that even with good care there will be years a bigleaf hydrangea does not bloom. In much of Canada this is the main cause. The winter protection guide covers what helps.
3. It Was a Gift Plant
Penn State Extension warns that a hydrangea received for Easter or Mother’s Day, in foil or a plastic sleeve, is often a florist’s hydrangea that is simply not winter hardy: the roots may survive, but the top and its flower buds do not.
4–7. Shade, Fertilizer, Water and Age
The University of Massachusetts lists the rest. Shade: bigleaf prefers morning sun and afternoon shade; too much shade reduces flowers. Fertilizer: too much nitrogen gives deep green leaves but few flowers, sometimes from lawn fertilizer washing into the bed. Water: drought stress reduces blooming, even the following year, and so can overwatering. Age: in its first season a new plant is building roots and may not flower much.
Frequently Asked Questions
Why is my hydrangea not blooming?
The two most common causes are pruning at the wrong time and winter-killed flower buds, both on bigleaf hydrangeas that bloom on old wood. Others are a non-hardy gift plant, too much shade, too much nitrogen, drought, and a young plant still establishing.
Did I prune my hydrangea at the wrong time?
If it is a bigleaf (mophead or lacecap) and you cut it back between fall and early spring, yes. Penn State Extension says that removes all the future flowers. Prune right after flowering and by August 1.
Why does my hydrangea have leaves but no flowers?
Often winter-killed buds or too much nitrogen. The University of Massachusetts notes excess nitrogen gives deep green leaves with few flowers.
Will my Easter hydrangea bloom in the garden?
Often not. Penn State Extension says gift or florist hydrangeas are usually not winter hardy; the roots may survive but the flower buds are killed.
Does shade stop hydrangeas blooming?
Too much shade reduces flowers. The University of Massachusetts says bigleaf prefers morning sun and dappled afternoon sun or part shade.
Should I switch to a different hydrangea?
If bigleaf rarely flowers in your garden, the University of Massachusetts suggests panicle hydrangea as a more reliable bloomer, though it will not give blue or lacecap flowers.
Sources
- Penn State Extension — Why Doesn’t My Hydrangea Bloom?
- University of Massachusetts Amherst Extension — Why Hydrangea macrophylla Don’t Flower
- University of Illinois Extension — For showy blooms, pruning hydrangeas is all about the timing