Hydrangea (Hydrangea spp.) – Plant Description

Hydrangeas are deciduous flowering shrubs known for their large, showy flower clusters and lush foliage. They are popular ornamental plants in gardens, landscapes, and containers.

General Appearance

Growth habit: Rounded, bushy shrubs ranging from 3 to 10 feet tall, depending on species and cultivar. Some climbing varieties exist (e.g., Hydrangea anomala subsp. petiolaris).

Foliage: Broad, oval to heart-shaped leaves with serrated edges; usually bright to deep green.

Stems: Woody at the base; new growth may be green or reddish.

Flowers

Bloom type: Large, rounded “mophead,” flattened “lacecap,” or cone-shaped panicles depending on species.

Color: Shades of blue, pink, white, purple, red, or green.

Some species (especially Hydrangea macrophylla) change color based on soil pH:

Acidic soil → blue

Alkaline soil → pink

Bloom time: Typically spring through late summer, with dried flower heads often persisting into fall or winter.

Growing Conditions

Light: Partial sun to partial shade; some species tolerate full sun with adequate moisture.

Soil: Moist, well-drained soil rich in organic matter.

Water: Regular watering—hydrangeas are moisture-loving and can wilt in heat.

Hardiness: Usually hardy in USDA zones 3–9, depending on the species.

Common Species

Hydrangea macrophylla – Bigleaf hydrangea (mophead or lacecap).

Hydrangea paniculata – Panicle hydrangea; cone-shaped blooms, sun-tolerant.

Hydrangea arborescens – Smooth hydrangea (e.g., ‘Annabelle’).

Hydrangea quercifolia – Oakleaf hydrangea; distinctive oak-like leaves and great fall color.

Notable Features

Striking, long-lasting blooms.

Excellent for borders, hedges, woodland gardens, and cut-flower arrangements.

Some varieties offer four-season interest with fall foliage and winter seed heads.