Hydrangea macrophylla, commonly referred to as bigleaf hydrangea, is one of the most popular landscape shrubs owing to its large mophead flowers. Although it does not have any serious insect or disease problems, Hydrangea macrophylla can be a challenging shrub for those looking for prolific and consistent blooms every year. 

Hydrangea macrophylla is a perennial shrub that has the unique ability to re-bloom throughout the spring and summer months. It is a deciduous shrub growing to 2 meters tall by 2.5 meters broad with large heads of pink or blue flowers in summer and autumn.

Hydrangea macrophylla blooms can be blue, red, pink, light purple, or dark purple. The color is affected by soil pH. An acidic soil (pH below 7) will usually produce flower color closer to blue, whereas an alkaline soil (pH above 7) will produce flowers more pink. This is caused by a color change of the flower pigments in the presence of aluminum ions which can be taken up into hyperaccumulating plants.