Hydrangea serrata ‘Beni-gaku’

mountain hydrangea

  • © Tim Wood

Outstanding Qualities

Hydrangea serrata 'Beni-gaku' features attractive tricolor, lacecap flowers on a compact, deciduous shrub. Flowers emerge white, then darken to pink with deep red edges. The small fertile florets are a dark purple, opening to light blue. As the season progress, all three colors are present at the same time. In fall the leaves turn dark purple. Complement 'Beni-gaku' with blue hostas, purpleleaf snakeroot (Actaea simplex 'Brunette'), and perennials with dark leaves or hot pink flowers. It works well in a woodland setting or a mixed shrub border.

Quick Facts

Plant Type: shrub

Foliage Type: deciduous

Plant Height: 5 ft. 0 in. (1.52 meters)

Plant Width/Spread: 5 ft. 0 in. (1.52 meters)

Plant Height-Mature: 8 ft. 0 in. (2.44 meters)

Plant Width-Mature: 8 ft. 0 in. (2.44 meters)

Hardiness: USDA Zones 6 to 9

Flower Color: pink

Sun/Light Exposure: light to open shade

Water Requirements: regular summer watering

Seasonal Interest: summer flowers and autumn foliage color

Colors & Combos

Great Color Contrasts: chartreuse, gold, burgundy

Great Color Partners: rose, lavender, white

Culture Notes
Mountain hydrangeas grow best in light to open shade. A location protected from hot sun will keep the foliage and flowers from prematurely fading or scorching. A humus-rich, well-drained soil produces the best growth and flowering. Hydrangeas are not drought tolerant and will grow and flower more prolifically with regular summer watering. The typically acidic soils of the Pacific Northwest will cause the variable flowers to bloom with purple and blue tones. For pink flowers, add lime to raise the pH and sweeten the soil. Have a soil test done to determine the amount of lime. Changing the color can often take a few years to accomplish with more than one application of lime. Remove a few old twiggy branches to the ground yearly or prune lightly to improve the overall shape. Heavy pruning can ruin the flowering for the following year. Consult an experienced pruner or take local classes before attempting substantial pruning.