Bigleaf Hydrangea.

At a glance

Care level

Moderate

Plant type

Deciduous flowering shrub

Light

Partial shade

Indoor light

bright-indirect

Water

Every 2 to 4 days

Mature size

3 to 6 feet tall and wide

Growth rate

medium

Hardiness

USDA 5 to 9

Bloom time

Summer

Care

Provide consistent moisture and protect from harsh afternoon sun. Prune after flowering to avoid removing next year's buds. Watch for signs of powdery mildew or leaf spot in humid conditions.

Watering

Keep soil consistently moist, especially during dry spells.

Feeding

Fertilize in early spring and again in early summer, using a balanced fertilizer or one formulated for hydrangeas.

Pruning

Prune immediately after flowering in summer to avoid removing next year's flower buds, which form on old wood.

Repotting

Repot container-grown plants when rootbound, typically every 1 to 2 years.

Soil

Well-draining, moist, humus-rich soil

Soil pH

Acidic (for blue flowers) to alkaline (for pink flowers)

Temperature

-17.8 to 29.4°C

Humidity

40 to 60%

Drought tolerance

low

Lifespan

Perennial, typically 10 to 20 years or more with good care.

Deer and rabbits

low

Safety

People

Ingestion of leaves, stems, or flowers can cause stomach upset, vomiting, and diarrhea.

Pets

Mildly toxic to cats and dogs if ingested, causing vomiting and diarrhea.

Children

The plant contains compounds that can cause gastrointestinal upset if ingested, so keep out of reach of small children.

Contact allergens

Sap may cause mild skin irritation in sensitive individuals.

Airborne allergens

Pollen may cause seasonal allergies in some people.

Edibility

This plant is not intended for human consumption.

How to identify it

• Large, mophead or lacecap flower clusters
• Opposite, serrated, ovate leaves
• Deciduous shrub with upright stems
• Flower color varies with soil pH
• Canes are woody and persistent

Height

0.91 to 1.83m

Spread

0.91 to 1.83m

Leaves

Green, deciduous

Flowers

Blue, Pink, Purple, White, Red, 15 to 30cm

Common problems

• Powdery Mildew — A white, powdery growth on leaves and stems, often in humid conditions.
• Aphids — Small, pear-shaped insects that feed on plant sap, causing distorted growth.
• Leaf Spot — Fungal or bacterial infections causing discolored spots on leaves.
• Bud Drop — Flower buds may fall off due to stress from drought, extreme temperatures, or transplant shock.

Growing it

Propagation

Cuttings, Division

When to plant

Spring, Fall

Overwintering

In colder climates, protect the plant by mounding mulch around the base after the ground freezes to insulate the roots and protect the lower stems, which often produce the best blooms. Avoid heavy pruning in fall, as flower buds form on old wood.

In containers

Yes, Hydrangea macrophylla can do well in containers, especially dwarf varieties. Use a pot at least 12-15 inches in diameter to allow for root growth.

Plant hydrangeas with other shade-loving perennials that also appreciate consistent moisture for a lush, cohesive look.

Grows well with

• Astilbe — Astilbes thrive in similar shady, moist conditions and offer a contrasting feathery texture.
• Hostas — Hostas provide beautiful foliage contrast in shady garden spots and appreciate consistent moisture.
• Ferns — Ferns complement hydrangeas with their delicate textures and love for shade and humidity.
• Coral Bells — Coral bells add color with their foliage and do well in partial shade alongside hydrangeas.

Keep away from

• Full Sun — Prolonged exposure to intense direct sunlight can scorch the leaves and stress the plant.
• Drought — Hydrangeas require consistent moisture and can suffer from wilting and bud drop if the soil dries out.
• Strong Winds — Strong winds can damage the large leaves and delicate flower heads.

Similar species

• Climbing Hydrangea — This species is a vining hydrangea, unlike the shrubby macrophylla, and has different growth habits and flower forms.
• Oakleaf Hydrangea — Oakleaf hydrangeas have distinct lobed leaves resembling oak leaves and offer beautiful fall color, differing from macrophylla's smooth leaves.
• Smooth Hydrangea — Smooth hydrangeas typically have more cone-shaped or flattened flower clusters and are often more cold-hardy than macrophylla.

Science

Family

Hydrangeaceae

Genus

Hydrangea

Order

Cornales

Class

Magnoliopsida

Native range

Native to Japan.

Conservation

Not of conservation concern.

In its native habitat, it grows in moist, shaded woodlands and along stream banks.

Value to wildlife

Provides some shelter

Uses

Ornamental, Cut flowers

Taxonomy resolved against GBIF.

Questions people ask

How do I change the flower color?

To get blue flowers, add aluminum sulfate to acidic soil. For pink flowers, add lime to raise the soil pH.

When is the best time to prune hydrangeas?

Prune after flowering in summer, as most varieties bloom on old wood.

Do hydrangeas need full sun?

They prefer morning sun and afternoon shade, especially in hotter climates.

Why are my hydrangea leaves turning yellow?

Yellowing leaves can be caused by nutrient deficiencies (especially iron), overwatering, or poor drainage.

Are hydrangeas deer resistant?

Generally, deer find hydrangeas quite palatable, so they are not considered deer resistant.

Where the name comes from

The genus name 'Hydrangea' comes from the Greek words 'hydor' (water) and 'angos' (vessel), referring to its need for water and cup-like flowers. The species name 'macrophylla' is Latin for 'large-leaved'.

Good to know

• The name 'Hydrangea' comes from the Greek words 'hydor' (water) and 'angos' (vessel), referring to its cup-like flowers and need for water.
• In Japan, hydrangeas were historically used to make tea.
• The color of the flowers is determined by the soil pH: acidic soil (low pH) produces blue flowers, while alkaline soil (high pH) produces pink flowers.
• Some varieties can grow quite large, reaching up to 6 feet tall and wide.