Endless Summer Bloomstruck Hydrangea

Light Needs

Part Shade to Part Sun

(3-6 Hours Direct Sun)

Mature Height

3-4 Feet

Mature Spread

4-5 Feet

Growing Zones

4 to 9

Endless Summer® BloomStruck Hydrangea (Hydrangea macrophylla 'PIIHM-II') is a reblooming bigleaf hydrangea that produces a season-long parade of large mophead flowers. The flowers range from deep rose in alkaline soil to violet-blue in acidic soil. Red-purple stems, dark green leaves, red petioles, and red veins give this shrub added interest before the flower heads fully open. 

This Endless Summer selection was bred by Bailey Nurseries and Dr. Michael Dirr from two well-known reblooming hydrangeas, The Original and Twist-n-Shout. It flowers on old and new wood, helping extend the bloom season while giving colder-zone gardeners another chance at summer flowers if some overwintered buds are lost. Endless Summer Bloomstruck Hydrangea grows 3 to 4 feet tall and 4 to 5 feet wide, with strong stems and above-average powdery mildew tolerance. Use it as an accent, low hedge, patio shrub, container feature, or mass planting where morning sun and afternoon shade support repeat color.

Endless Summer Bloomstruck Hydrangea Care

Plant Endless Summer Bloomstruck Hydrangea in part shade, ideally with morning sun and afternoon protection. Rich, moist, well-drained soil supports the best flowering and helps the large leaves hold up through summer heat. Soil pH controls bloom color, with acidic soil encouraging blue to violet-blue flowers and alkaline soil encouraging deep rose tones.

Water deeply during the first growing season. Once established, provide steady moisture when rainfall is limited. On hot afternoons, leaves may droop as a heat response and recover when temperatures cool, so check the soil before adding more water. Fertilize in early to mid-spring with a balanced fertilizer, and avoid heavy nitrogen that can favor leaves over flowers. Mulch the root zone with shredded bark, compost, or leaves to conserve moisture and protect roots through winter.

Pruning should stay light because Bloomstruck flowers on both old and new growth. Remove dead, damaged, or crossing stems in spring as new buds begin to show, and deadhead faded flowers during the season for a cleaner look. Avoid fall pruning and protect the crown with a generous mulch layer to help preserve flower buds in Zones 4 and 5.

Endless Summer Bloomstruck Hydrangea Spacing

Space Endless Summer Bloomstruck Hydrangea 4 to 5 feet apart for hedges or grouped plantings. Allow 5 to 6 feet for a single specimen so the rounded-to-spreading habit has room to develop. For containers, choose a wide pot at least 18 to 22 inches across with drainage holes and a high-quality potting mix that holds moisture without staying saturated.

For part-shade beds, pair Endless Summer Bloomstruck Hydrangea with hostas, primrose, Jacob’s Ladder, or barrenwort and provide steady moisture. Sweetspire and fothergilla can add seasonal flowers and fall foliage while staying comfortable in similar soil conditions. In large containers, use coleus or fuchsia around the hydrangea for shade-friendly foliage and flowers that can handle regular watering.

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