Scientific Name: Hydrangea serrata ‘Bluebird’ Common Name: Mountain (Lacecap) Hydrangea Garden Size: 4-6 ft. x 4-6 ft. USDA Zone: 5 to 9 Native Range: Japan, Korea Exposure: Part Shade Water & Soil: Average, Medium Moisture; Well-drained Soil Habit (Form): Small, Compact, Rounded Foliage: Deciduous, Warm Green Leaves Bloom Time: Blooms on Old Wood, June to July Bloom Color: Blue to Pink Flowers, Domed Flower Heads (See additional information) Uses: Mass or Group in Shrub Border, Accent for Foundation Plantings, Woodland Garden Care: Prune these hydrangeas only in the summer before August, before they set their bloom buds for the next year. Mountain Hydrangeas produce flower buds on stems around August, September or October for the following summer’s blooms. If those stems are removed (pruned) in the fall, winter, or spring, the bloom buds will be removed, and there may be little or no bloom the following summer. Additional Information: Soil pH affects the bloom color of most Hydrangea macrophylla cultivars except white (Blue in highly acidic soils and lilac to pink in slightly acidic to alkaline soils). Add aluminum sulfate to the soil to make the flowers bluer or add lime to the soil to make the flowers pinker. Add in late autumn or early spring.