The holly plants (3) have blackening leaves with a few white coccoon like things about 1/8 in. long on the under side of the dying leaves. What is it and what is the treatment to save plant?
Wilting Holly Shrub
Hopefully these two articles will help: https://www.gardeningknowhow.com/ornamental/shrubs/holly/growing-holly-bushes.htm
You may have mealybugs...This article talks about mealies on houseplants, but it's the same for landscape plants: https://www.gardeningknowhow.com/plant-problems/pests/mealybugs-white-residue-on-plants-leaves.htm