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Guide botanique

Bigleaf Hydrangea.

Hydrangea macrophylla

Prononciation hy-DRAYN-jee-uh mak-ROH-fil-uh

Aussi appelée Bigleaf Hydrangea, Chinese sweetleaf, French hydrangea, Hydrangea, common hydrangea, hortensia

mophead hydrangea
Photo de Claude Kolwelter (CC BY) via iNaturalist

The Bigleaf Hydrangea is a beloved flowering shrub, famous for its large, showy flower clusters that can change color based on soil pH. It brings a touch of classic cottage garden charm to any landscape.

En un coup d'œil

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

Entretien

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

Signes qu'il faut rempoter

  • Roots growing out of the drainage holes.
  • Water drains very slowly or not at all.
  • Plant dries out much faster than usual.
  • Visible salt or mineral buildup on the soil surface or pot rim.

Sécurité

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.

Comment l'identifier

  • 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

Problèmes courants

  • 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.

La cultiver

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.

Softwood Cuttings

  1. Take 4-6 inch cuttings from new growth in late spring or early summer.
  2. Remove lower leaves and dip the cut end in rooting hormone.
  3. Insert cuttings into a moist potting mix.
  4. Keep the cuttings in a humid environment (e.g., under a plastic bag or in a propagator) with bright, indirect light.
  5. Roots should form within 4-6 weeks.

Layering

  1. Choose a low-growing stem that is still attached to the parent plant.
  2. Bend the stem to the ground and wound the underside where it will contact the soil.
  3. Bury the wounded section in moist soil, securing it with a rock or landscape staple.
  4. Keep the area moist.
  5. Roots should form by the following spring, at which point the stem can be cut from the parent plant.

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

Bonnes associations

  • 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.

À éloigner de

  • 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.

Espèces similaires

  • 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

Au fil des saisons

JFMAMJJASOND
Flowering
Fruiting
Foliage

Repères écologiques

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

Taxonomie vérifiée avec le GBIF.

Ce qu'on demande souvent

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.

D'où vient le nom

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'.

Bon à savoir

  • 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.

Ton bigleaf hydrangea a mauvaise mine ?

Cette page est un guide général. Pocket Botanist diagnostique les problèmes directement à partir d'une photo de ta plante, adapte l'arrosage à sa luminosité et te prévient quand il faut t'en occuper.

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Ce guide a été généré par IA et vérifié avec la taxonomie du GBIF. Il s'agit d'informations générales, et non de conseils horticoles ou vétérinaires. Découvre comment nous concevons ces guides.