The inflorescence of Hydrangea macrophylla is a corymb, with all flowers placed in a plane or hemisphere, or even a whole sphere in cultivated forms.

The four sepals of decorative flowers have colors ranging from pale pink to red fuchsia purple to blue.

[9] This is caused by a color change of the flower pigments in the presence of aluminium ions which can be taken up into hyperaccumulating plants.

Its rich foliage and large size make it a wonderful background for white or light colored flowers, even tall growing perennials and annuals.

In warm climates H. macrophylla is good for adding a splash of early summer color to shady areas and woodland gardens.

This may be due to cold winter damage to the flower buds, not getting enough sunlight, too much nitrogen fertilizer, or pruning at the wrong time of year.

[15] The various colors, such as red, mauve, purple, violet and blue, in H. macrophylla are developed from one simple anthocyanin, delphinidin 3-glucoside (myrtillin), which forms complexes with metal ions called metalloanthocyanins.

Hydrangeae Dulcis Folium is a drug made from the fermented and dried leaves of H. macrophylla var.

[20] Hydrangea macrophylla is included in the Tasmanian Fire Service's list of low flammability plants, indicating that it is suitable for growing within a building protection zone.

[21] Leaf extracts of Hydrangea macrophylla are being investigated as a possible source of new chemical compounds with antimalarial activity.

[24] Some popular hydrangea cultivars (those marked agm have gained the Royal Horticultural Society's Award of Garden Merit) include:[25] Yuan, Qi, H., Yang, S., Chu, Z., Zhang, G., & Liu, C. (2023).