Q.My 13 Year Old Pyracantha Suddenly Looks Like It Is Dying. All Of The Leaves Are Brown And Curling. What Can I Do Please.
It is possible that weed killer has been applied (not by me) next to a path which is next to the pyracantha – could this cause the damage?
Certified GKH Gardening Expert
This could, certainly, be the culprit. It could resemble fire blight, but this doesn't seem likely with the speed of progression. Here are some articles that will help:
https://www.gardeningknowhow.com/plant-problems/environmental/herbicide-plant-damage.htm
https://www.gardeningknowhow.com/plant-problems/disease/fire-blight-remedies-and-symptoms.htm
https://www.gardeningknowhow.com/ornamental/shrubs/firethorn/care-of-firethorn-bush.htm