Hydrangea macrophylla 'Hamburg'

Hydrangea macrophylla 'Hamburg' is a deciduous bigleaf hydrangea with broad, dark-green leaves and large, rounded mophead flower clusters. Its florets range from deep rose to purple-blue with soil conditions, then may age wine-red in autumn, creating a vivid display in a partly shaded border or container. ## Flowers and Placement The [Hamburg cultivar profile](https://www.gardenia.net/plant/hydrangea-macrophylla-hamburg) describes heads up to about 20 cm across and a compact, bushy shrub around 1.2–1.5 m tall and wide. Color depends partly on soil pH and available aluminum: more acidic conditions can favor blue-violet tones, while less acidic soil tends toward pink. The [Royal Horticultural Society profile](https://www.rhs.org.uk/plants/117180/hydrangea-hortensia-hamburg/details) places this selection in the deciduous mophead group. ## Growing Conditions Choose morning sun or partial shade and rich, consistently moist but well-drained soil. Bigleaf hydrangeas tolerate more sun when the root zone stays moist; shield this shrub from hot afternoon exposure. [NC State Extension](https://plants.ces.ncsu.edu/plants/hydrangea-macrophylla/) describes the species’ moisture, shade, and old-wood flowering needs. ## Maintenance Water during dry spells and mulch to slow moisture loss. Flower buds form on older stems, so shape the shrub just after flowering rather than pruning late in the season; remove winter-damaged or weak wood in spring.