Hydrangea serrata, lacecap hydrangeas, are compact deciduous shrubs with clusters of small fertile flowers, surrounded by showy sterile flowers, in summer.
Hydrangea serrata 'Mont Aso' was discovered growing on Mount Aso in Japan. It is a compact cultivar that bears flat flowerheads of pink, blue or purple - the flowers are lilac-blue on acidic soils and purple or pink on neutral or slightly alkaline soils. The foliage colours up beautifully in autumn, with tints of red, orange and purple.
Hydrangea serrata 'Mont Aso' prefers moist, fertile soil. It looks good growing with other hydrangeas or shrubs, or large perennials.