Why are the leaves on your hydrangea falling?

Leaves on a hydrangea may fall due to several reasons, including environmental stress, such as drought or excessive heat, which can cause the plant to conserve water. Overwatering or poor drainage can lead to root rot, resulting in leaf drop. Additionally, pests or diseases may affect the plant's health, causing leaves to wilt and fall. Seasonal changes can also play a role, especially in autumn when some varieties naturally shed their leaves.