Hydrangea serrata 'Isusai-jaku' (L) (Mountain Hydrangea)

About

Hydrangea serrata 'Isusai-jaku' is a cultivar of mountain hydrangea valued for its lace-cap flowerheads and compact habit. It is a deciduous shrub reaching about 1.2 m tall and broad with ovate, serrated leaves to roughly 15 cm long. Flowerheads emerge from June to September and may be blue or pink. The foliage is dark green through the growing season.

About the genus

Hydrangea is a genus of more than 70 species of flowering plants native to Asia and the Americas. Hydrangea is also used as the common name for the genus; some are also often called hortensia. The genus was first described from Virginia in North America, but by far the greatest species diversity is in eastern Asia, notably China, Korea, and Japan.

Wikipedia contributors, "Hydrangea", CC BY-SA 4.0 — Hydrangea

In the garden

Hydrangea serrata 'Isusai-jaku' is a cultivated form of Hydrangea serrata (family Hydrangeaceae), a mountain hydrangea native to the upland regions of Korea and Japan. It follows the species' smaller stature, forming a rounded shrub of about 1.2 m in both height and spread, with toothed, ovate leaves and lace-cap clusters of fertile and sterile florets. Flowering runs from June to September, producing blooms that can be blue or pink. The species is noted for tolerating cooler, upland conditions better than the larger garden hydrangeas, so this cultivar suits sites where a more moderate-sized shrub is required. Provide a position where soil remains reasonably moist and where late frost and drying winds are minimised to protect developing flowerbuds. Because of its size and long season of interest, Hydrangea serrata 'Isusai-jaku' fits well at the front of mixed borders, in a woodland-edge planting or where a smaller specimen shrub is needed. Its lace-cap flowerheads give a clear mid-summer to early-autumn presence in the garden, carrying colour from June through to September.

More in the Hydrangea genus

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