The BloomStruck Hydrangea (Hydrangea macrophylla 'PIIHM-I' BloomStruck) is a deciduous flowering shrub belonging to the Bigleaf Hydrangea species. Known for its large mophead flowers, it is part of the Endless Summer series, offering a more extended blooming period by flowering on both old and new wood. Here are key features:

1. Flowers: The mophead flowers are large, rounded, and consist of both sterile and fertile florets. Their color varies based on soil pH, appearing blue in acidic soil and pink in alkaline soil.

2. Reblooming: As part of the Endless Summer series, BloomStruck can bloom repeatedly, enhancing its overall flowering duration.

3. Foliage: The dark green, serrated foliage provides a lush backdrop to the colorful blooms.

4. Size: A relatively compact hydrangea, reaching a mature size of 3 to 4 feet in height and 4-5 feet in width.

5. Sun Requirements: Prefers partial shade, benefitting from protection against the hot afternoon sun in warmer climates.

6. Soil: Well-drained soil is essential, and the flower color is influenced by soil pH. Acidic soil promotes blue tones, while alkaline soil promotes pink tones.

7. Hardiness: Hardy in USDA Hardiness Zones 4 to 9.

8. Landscape Use: Commonly used as a focal point in gardens, mixed borders, or in containers. Suitable for various garden styles, both formal and informal.

9. Pruning: Minimal pruning is recommended. If needed, prune after the first flush of blooms in late spring or early summer. Removing spent blooms can encourage additional flowering.

10. Disease Resistance: BloomStruck Hydrangea exhibits good overall disease resistance. Proper care, including adequate spacing and watering, helps maintain plant health.

11. Winter Interest: The dried flower heads can provide winter interest if left on the plant.

The BloomStruck Hydrangea is a popular choice for its vibrant blooms, reblooming capabilities, and versatility in garden design. Paying attention to soil pH can influence flower color, and providing appropriate care supports the health and performance of this attractive hydrangea.