Why are my hydrangeas not blooming?

This is often due to late spring frosts killing the buds or improper pruning.

Prune immediately after flowering to avoid cutting off next year's buds.

Plant guide

Bigleaf Hydrangea.

Hydrangea macrophylla (Thunb.) Ser.

Pronounced hy-DRAN-jee-uh mak-ro-FIL-uh

Also known as Bigleaf Hydrangea, Chinese sweetleaf, French hydrangea, Hydrangea, common hydrangea, hortensia

mophead hydrangea — Photo by zebedeugalinha (CC BY) via iNaturalist

Bigleaf hydrangeas are beloved for their massive, showy flower heads that change color based on soil acidity. They bring a classic, lush feel to any garden space. These shrubs thrive when they get plenty of moisture and protection from the harsh afternoon sun.

Another photo of Bigleaf Hydrangea — Photo by Frank Ashwood (CC BY) via gbif

At a glance

Care level: Moderate
Plant type: Deciduous shrub
Light: Morning sun and afternoon shade
Indoor light: Bright indirect
Water: Every 2 to 4 days
Mature size: 3 to 6 feet
Growth rate: Medium
Hardiness: USDA 5 to 9
Bloom time: Late spring to late summer

Care

Keep the soil consistently moist but never soggy to prevent root issues. Watch for wilting leaves during hot afternoons, which signals the plant needs a drink. You can influence bloom color by adjusting your soil pH with amendments.

Watering: Water deeply whenever the top inch of soil feels dry to the touch.
Feeding: Apply a balanced fertilizer once in early spring and again in late spring.
Pruning: Prune immediately after flowering to avoid cutting off next year's buds.
Repotting: Repot only if the plant becomes root-bound or needs a larger container for better moisture retention.
Soil: Rich, well-draining, organic soil
Soil pH: 5.0 to 7.0
Temperature: -15 to 35°C
Humidity: 50 to 70%
Drought tolerance: Low
Lifespan: Perennial, typically 10 to 20 years
Deer and rabbits: Low

Signs it needs repotting

Roots growing out of the drainage holes
Water running straight through the pot
Stunted growth during the active season

Safety

People: All parts of the plant contain cyanogenic glycosides which are toxic if eaten.
Pets: This plant is toxic to cats and dogs if ingested, as it contains cyanogenic glycosides.
Children: Keep this plant away from small children as ingestion of leaves or flowers can lead to stomach upset.
Contact allergens: Handling the foliage may cause mild skin irritation in sensitive individuals.
Airborne allergens: The pollen is generally not considered a significant airborne allergen.
Edibility: This plant is not intended for consumption and can cause gastrointestinal distress if ingested.

How to identify it

Large, serrated, oval leaves
Showy mophead or lacecap flowers
Woody, multi-stemmed shrub habit
Flowers shift color with soil pH

Height: 0.9 to 1.8m
Spread: 0.9 to 1.8m
Leaves: green, deciduous
Flowers: blue, pink, purple, white, 10 to 25cm

Problems to watch for

AphidsCommon
Leaf ScorchCommon
Powdery MildewCommon
Botrytis BlightUncommon
ChlorosisUncommon
Root RotUncommon

By symptom

Check your bigleaf hydrangea from a photo

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Growing it

Propagation: cuttings, division
When to plant: spring, autumn
Overwintering: Apply a thick layer of mulch around the base to protect roots from freezing temperatures. If you live in a very cold area, wrap the stems in burlap to protect the flower buds.
In containers: They grow well in large pots, provided you use a container at least 40 centimeters in diameter with good drainage.

Softwood cuttings

Take a 10 centimeter cutting from a non flowering stem in early summer.
Remove the lower leaves and dip the end in rooting hormone.
Place in a moist potting mix and cover with a plastic bag to maintain humidity.
Keep in bright, indirect light until roots form.

Pair with other shade loving perennials that appreciate consistent moisture to create a lush woodland look.

Grows well with

Hosta — They share similar requirements for shade and moisture.
Astilbe — These provide a nice textural contrast in shady borders.

Similar species

Oakleaf Hydrangea — It offers distinct foliage and better drought tolerance.
Smooth Hydrangea — This species blooms on new wood, making it easier to manage.

Science

Family: Hydrangeaceae
Genus: Hydrangea
Order: Cornales
Class: Magnoliopsida
Native range: Japan and East Asia
Conservation: This species is not currently of conservation concern.

It thrives in cool, moist, shaded woodland edges where it can access consistent soil moisture.

Value to wildlife: nectar source
Pollinators: bees, butterflies
Uses: ornamental shrub, cut flowers, foundation planting

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Moisture: 7/9
Nutrients: 6/9
Soil reaction: 5/9
Light: 4/9
Temperature: 5/9

Taxonomy resolved against GBIF.

Questions people ask

Why are my hydrangeas not blooming?: This is often due to late spring frosts killing the buds or improper pruning.
How do I prune them?: Prune immediately after flowering to avoid cutting off next year's buds.

Where the name comes from

The genus name Hydrangea is derived from Greek words meaning water vessel, while macrophylla means large leaf.

Good to know

Hydrangeas are native to Japan and were introduced to Europe in the eighteenth century.
The name comes from the Greek words for water and vessel, referring to the seed pods.
You can change the color of your blooms by adding aluminum sulfate or lime to the soil.

Also in

Plants toxic to cats and dogs

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This guide was generated with AI and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.