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Mountain hydrangea

  • Trees and Shrubs
Hydrangea serrata 'Beni Gaku'
Photo: Gilles Murray
 Hydrangea serrata 'Beni Gaku'



Origin and description

This small shrub (1 m x 80 cm) closely resembles H. macrophylla but it is slightly more hardy (Zone 5a). The leaves of most cultivars turn red in the fall. Flower heads, comprised of flat corymbs, are formed by a ring of sterile flowers surrounding a centre of fertile flowers (marginalis). The flower colour is less influenced by soil acidity but varies slightly over the growing season.

Species, cultivars and related plants

‘Arctic Blue,’ ‘Blue Billow,’ ‘Beni-Gaku,’ ‘Bluebird,’ ‘Golden Sunlight,’ ‘Preziosa’.


All parts of the plant are poisonous.

Common name

Mountain hydrangea

Latin name (genus)

Hydrangea serrata

English common name

French common name

Botanical family

  • Hydrangeaceae

Growing conditions

Lighting conditions

Sun or partial shade.


Rich, cool, well-drained, acidic to slightly alkaline.

Hardiness and protection

Hardy to Zone 5, the base of the plant should be covered with a good layer of shredded-leaf mulch (30 cm) and snow accumulation encouraged for the best winter protection.

Pruning and maintenance

The flowers bloom on old wood, so prune lightly. Pruning too heavily (coppicing) will prevent it from flowering that year. In the fall, just cut the stems that have flowered above a pair of healthy buds and cover with mulch. In spring, prune to remove any stem sections damaged by the cold.


  • Zone 5

See also

Pests and diseases
Physiological disorders

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