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Big-leaved hydrangeas are valued for their showy flowers. However, in Zone 5 and lower, these small shrubs from Japan are generally not flowerbud hardy in cold winters. This type of hydrangea sets its flower buds on the previous year’s growth (old wood), so they are more susceptible to freeze damage. In recent years, some cultivated varieties have been developed that are somewhat hardier. But even the new cultivars will do better if placed in a protected location and are covered with snow throughout the winter.

Blue flowers are one of the plant’s appeals, but big-leaved hydrangeas only have blue flowers when planted in acid soils. In alkaline soils, such as those in most of the Chicago region and the Great Plains, the flowers will be pink. Flower clusters will vary by cultivar. Some cultivars have large clusters of mostly showy (sterile) flowers, with a few non-showy (fertile) flowers in the interior of the cluster. These are often referred to as mopheads. Other cultivars have lacecap-type clusters. These usually feature a center of non-showy (fertile) flowers surrounded by an outer ring of the showy (sterile) flowers.

The species and older cultivars bloom only on old wood. In zone 5, the plant often dies to the ground in winter so there is no old wood, and no flowers. Many newer cultivars will bloom on old and new wood (current season’s growth). Thus, if the old wood dies back, the plant can still bloom on the new wood.

  • Family (English) Hydrangea
  • Family (botanic) Hydrangeaceae
  • Tree or plant type Shrub
  • Native locale Non-native
  • Size range Low-growing shrub (under 3 feet), Small shrub (3-5 feet)
  • Light exposure Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 5 (Chicago), Zone 6, Zone 7, Zone 8, Zone 9
  • Soil preference Acid soil, Moist, well-drained soil
  • Tolerances Alkaline soil
  • Season of interest early fall, early summer, late fall, late summer, mid fall, midsummer
  • Flower color and fragrance Blue, Pink
  • Shape or form Multi-stemmed, Round
  • Growth rate Fast

Size and Form: 

Big-leaved hydrangeas typically grow 3 to 5 feet high and 3 to 5 feet wide. The newer cultivars can vary in size. They are multi-stemmed with a rounded form.

Native geographic location and habitat: 

Big-leaved hydrangea is native to Japan.

Bark color and texture: 

The stems are green to light gray or light brown.

Leaf or needle arrangement, size, shape, and texture: 

The leaves are simple and opposite with toothed margins. They are 4 to 8 inches long.

Flower arrangement, shape, and size: 

These plants bloom mostly on old wood.  Severe winters will kill the flower buds, but the leaf buds will survive. Large flower clusters may vary by cultivar.  Some cultivars have large clusters of mostly showy (sterile) flowers, with a few non-showy (fertile) flowers in the interior of the cluster.  These are often referred to as mopheads. Other cultivars have lacecap-type clusters.  These usually feature a center of non-showy (fertile) flowers surrounded by an outer ring of the showy (sterile) flowers. Flowers can be blue in acid soils, but will be pink in alkaline soil.

Fruit, cone, nut, and seed descriptions: 

The actual fruit (a dry capsule) is not ornamentally important, but the remains of the dry flower heads that surround them do provide winter interest.

Plant care: 

Big-leaved hydrangeas grow best in part shade. Some cultivars will tolerate full sun when provided with adequate soil moisture and a layer of mulch. Plant them in a moist, well drained, moderately fertile soil. The plants are drought sensitive, so be sure to water during dry periods. They should be protected from winter winds and extreme cold temperatures. Prune out the dead stems in early spring. The newer cultivars bloom on both old and new wood.

List of pests, diseases, and tolerances: 

This plant has no serious pests.

All Summer Beauty (Hydrangea macrophylla ‘All Summer Beauty’): 

This cultivar has a mophead-type flower cluster. The nearly rounded flower heads are up to 8 inches across. It will have a blue flower in acid soil, and a pink flower in alkaline soil. It flowers on both old and new wood. 

Blushing Bride (Hydrangea macrophylla ‘Blushing Bride’): 

This plant has a mophead-type flower cluster. The white (semi-double) flowers blush pink with age. It blooms on new and old wood. It is part of the Endless Summer® Collection.

Endless Summer® (Hydrangea macrophylla ‘Bailmer’): 

This 3 to 4 feet tall plant has a mophead-type flower cluster. It will have pink flowers in our alkaline soils (blue in acid soils). It blooms on new and old wood, but it is an inconsistent bloomer. 

Light-O-Day® (Hydrangea macrophylla ‘Bailday’): 

This cultivar has a lacecap-type flower cluster with white showy sterile flowers on the outer ring surrounding small pink fertile flowers. It blooms on new and old wood and has variegated foliage. 

Nikko Blue (Hydrangea macrophylla ‘Nikko Blue’): 

This plant has a mophead-type flower cluster with large rounded flower heads.  It will be blue in acid soil, pink in alkaline soil. It blooms on last year’s woody stems, leaving flower buds vulnerable to winter damage. It seldom blooms in zone 5. It has dark green leaves in summer.

Pia (Hydrangea macrophylla ‘Pia’):

 A dwarf cultivar, growing only 2 feet tall, this mophead-type hydrangea has pink flowers. It blooms on old wood only, but is considered hardy to zone 5.

Twist-n-Shout™ (Hydrangea macrophylla ‘PIIHM-I’):

This has a lacecap-type flower cluster which blooms on both old and new wood. Its sturdy red stems support abundant flowers in which deep pink is surrounded by pink or periwinkle blue, depending on the soil type. Glossy deep green leaves turn burgundy in fall. It is part of the Endless Summer® Collection.

Variegata (Hydrangea macrophylla ‘Variegata’): 

This has a lacecap-type flower cluster with rosy pink flowers up to 4 inches wide. It has variegated leaves with light and dark green areas and creamy or silvery-white margins. It flowers on old wood only.

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