Brown leaves on Weigela bush

Question

My Weigela has suddenly developed brown leaves on one side of the bush. Do you know the reason for this?

Answer 1

Weigela Shrubs can become infected with Mealybug or Gray Mold.
Environmental issues also could cause brown leaves. If it's a new planting Leaf Scorch could be a possibility.
Inspect the plant and I would recommend a Neem Oil treatment. It is both a fungicide and pesticide.

https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm

https://www.gardeningknowhow.com/ornamental/shrubs/weigela/growing-weigela.htm