Foster Holly. Starts with tips of leaves turning brown, with some having brown around the border of entire leaf. Can you identify disease and suggest a treatment?
Holly Bush Diseases
Certified GKH Gardening Expert
It is difficult to say for sure, as this could be attributed to a number of things. Usually brown leaves signify that they need more water. Using root stimulator solution on the plants once a month for at least six months may help too, provided that the issue is not root rot. If the bark is still green, the plants are still alive, and even if they lose all or the majority of the leaves, they should eventually leaf back out. Another possibility is scorch, if they're getting too much sun. This article has more information: https://www.gardeningknowhow.com/plant-problems/environmental/what-causes-brown-edges-on-leaves-of-plant.htm