Why is my holly tree dying?
I have four holly tees on my wooded lot and they all get approximately the same amount of sun and are seemingly healthy, except one. It showed a sudden die-off that I first noticed in January. Leaves on 3/4 of the tree are brown, but some at the back and lower part of the tree are still green. On closer inspection, it looks as if there has been insect infestation at the same level on the problem branches, but I have not found anything that indicates the solution to my problem through my on-line research. Are the affected branches doomed for good or is there a treatment? If I cut off major limbs below the infestation, can the tree come back with new shoots? Can you analyze the problem through my attached photos and offer me advise? Although I watered a lot throughout last summer, the tree is surrounded by azaleas and three tulip poplars — mulching has been less than probably necessary, despite leaf cover. Your advice?
Many broadleaf evergreens -- and especially hollies -- suffered winter damage this year. It's unusual, however, that the symptoms are just on one of your four hollies. Perhaps it is in a location that is dryer and more susceptible to drying winds. Winter injury can occur on dry, windy, warm or sunny winter days when the ground is frozen. Plants are unable to move water from the frozen soil to replace the water being lost from the exposed leaves. Leaves curl and droop, then brown from the tips and margins, giving them a scorched appearance. https://extension.umd.edu/hgic/winter-damage-trees-and-shrubs
We also notice in your photo that there is sapsucker damage on the trunk of the tree. This may have been a factor in weakening the health of this particular plant. Read about sapsucker damage here: https://extension.umd.edu/hgic/woodpeckers-and-sapsuckers
Wait until you see new leaves developing on the plants. If winter injury did not kill the leaf buds, you will get new growth. Where there is no new growth, you can prune out dead branches.