Q.Mature dwarf mugo pines are almost all brown with needles falling off. Could they be drowning from too much rain?
Mugos are around 40 years old and always healthy. They are turning brown quickly with falling needles – less than two weeks. Only about 1/4th of the plants are green. What is most likely cause? Can they be saved? Weather is fluctuating but still below 20 degree nights and more snow on the way. Were fed with Hollytone in the fall. Foundation plants in front of house.
Certified GKH Gardening Expert
Overly wet conditions could be the problem which could contribute to root rot or fungal disease. Pest infestation is also a possibility. It's hard to tell from the photo. I would contact the local extension service in your area for a definitive diagnosis. Did you by any chance use a salt de-icer that is getting into the ground near them? That could kill them.
https://extension.umd.edu/baltimore-county
https://www.gardeningknowhow.com/ornamental/trees/pine/mugo-pine-information.htm
https://www.gardeningknowhow.com/ornamental/trees/pine/pine-tree-drying-bottom.htm