PLNTversePLNTverse
Plants › Flowering shrubs

Bigleaf Hydrangea (Hydrangea macrophylla)

Hydrangea macrophylla is a perennial deciduous plant, generally growing as a multi-stemmed woody shrub, although sources differ and some describe the wild form as a subshrub.

LightPartial sun, dappled light, or shade is suitable; some sources also indicate that full sun is acceptable, though direct sun during the hottest part of the day is best avoided in hot or low-rainfall areas.
WaterIt requires consistent moisture and suits moist but well-drained soil; the roots should not remain dry for prolonged periods or become excessively waterlogged.
HumidityIt is reported to prefer high humidity and to need little air movement.
TemperatureSources differ, with the few available accounts placing the minimum temperature at about -10 °C. A USDA hardiness-zone range is reported, and the plant is generally reported to tolerate brief light frost.
Track your Bigleaf Hydrangea in the PLNTverse app
Bigleaf Hydrangea illustration

Overview

Hydrangea macrophylla is a perennial deciduous plant, generally growing as a multi-stemmed woody shrub, although sources differ and some describe the wild form as a subshrub.

Origin and habitat

Sources differ on the native range, with Japan given as the native area. In Japan it occurs in coastal areas and in woodland or sunny sites near the coast, and in cultivation it is also widespread in gardens, parks, and other human-made environments. It is widely cultivated in various climates, especially in temperate regions.

Characteristics

Sources differ on mature height, with the few available accounts placing it at about 100–300 cm, while mature spread is 91–300 cm and growth is rapid. The simple, opposite leaves are usually ovate to elliptic, with pointed tips and serrated margins. The large inflorescences may be corymb-like, cymose, or nearly spherical and may be white, pink, red, purple, or blue; typical wild forms have smaller fertile flowers in the center and large, conspicuous sterile flowers around them, while cultivated forms may have spherical mophead or flat lacecap inflorescences, with some flower colors influenced by soil pH and aluminum availability. Sources differ on the flowering period, describing flowering from late spring into autumn with summer as the main flowering period; the fruit is generally reported to be a nearly spherical capsule.

Light

Partial sun, dappled light, or shade is suitable; some sources also indicate that full sun is acceptable, though direct sun during the hottest part of the day is best avoided in hot or low-rainfall areas.

Watering

It requires consistent moisture and suits moist but well-drained soil; the roots should not remain dry for prolonged periods or become excessively waterlogged.

Humidity and airflow

It is reported to prefer high humidity and to need little air movement.

Temperature and dormancy

Sources differ, with the few available accounts placing the minimum temperature at about -10 °C. A USDA hardiness-zone range is reported, and the plant is generally reported to tolerate brief light frost.

Growing medium and mounting

It adapts to various soils, including clay and sandy soils, and does best with good drainage and moderate moisture; it tolerates acidic through alkaline soils, although shallow calcareous soil may cause yellowing. Growing-medium pH and aluminum availability can influence some flower colors.

Feeding

The soil should contain organic matter and mineral nutrients, and horticultural materials that affect soil pH or aluminum availability may also be used to adjust the flower color of some cultivars.

Propagation

It can be propagated by stem cuttings or layering, with cuttings being a common method; agricultural information from Taiwan recommends taking cuttings from the previous year's shoots before early-spring bud growth and reports that they root after a period of time.

Common problems

It is reported to be relatively susceptible to root-rot disease caused by honey fungus. Shallow calcareous soil may cause leaf yellowing, while pruning too late may interfere with flower-bud formation and affect the following flowering period. New spring shoots are sensitive to frost, and in hot, low-rainfall conditions strong direct sun during the hottest part of the day and drying of the roots should be avoided.

Identification

Large opposite serrated leaves and conspicuous large inflorescences are key identifying features; the inflorescences may be flat lacecap types or nearly spherical mophead types, and colors such as blue and pink can be influenced by growing-medium pH and aluminum availability.

Photos

Hydrangea macrophylla
📷 belvedere04 · CC BY 4.0 · source
Hydrangea macrophylla
📷 Tony Rebelo, some rights reserved (CC BY-SA), uploaded by To · CC BY-SA · source

Sources