Q.My Weigela
My weigela has flowered and now I am noticing that the leaves are starting to fall…..it this normal?
Inspect the plant for signs of Scale pests. Weigela can be susceptible to infestations and leaves may yellow and then drop off the plant.
Heavy infestations can kill the plant.
Neem Oil can be used to treat these pests.
Check the watering. Weigela can be susceptible to crown or root rot. Make sure the soil is well draining.
Here are some links with more information.
https://www.gardeningknowhow.com/ornamental/shrubs/weigela/growing-weigela.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm