Daphne dropping leaves that have turned yellow

Question

I have a daphne caucasian x collins growing for many years in a patio planter. Recently leaves are turning yellow and dropping. It is a mature shrub about 3 ft wide x 2 ft tall.

Thank you.

Answer 1

Yellowing leaves can indicate watering issues, disease or pests.
This article will help you review care.
https://www.gardeningknowhow.com/ornamental/shrubs/winter-daphne/pruning-winter-daphne.htm