Treating variegated red twig dogwood
Leaves are turning red on established variegated red twig dogwood bushes. What does this mean? Lost one bush already. What can I do to save the others?
Dogwood is effected by a few different diseases.
From your description, I would say it is likely Septora Leaf Spot.
I have listed some links for you that include images to help you pinpoint the cause and determine if treatment is necessary.