Infestation advice for native holly tree
One of the holly trees in the woods around my house (we have about 2.25 acres in Gambrills, MD) appears to have something infesting the trunk for about a foot about 5 or 6 feet above the ground. I'll attach a photo - the leaves above that infested foot of trunk are completely brown this year (I thought it was from the winter), but the branches still seem alive. Below the infestation, the tree is trying to send out new branches. I am not sure if the same infestation is also attacking a nearby boxwood, but it also now is showing wilting leaves at the ends of several branches. I don't want this spreading through my woods.
Based on the photos that you sent it looks like the holly was subject to possible winter damage, a root problem, and/or sapsucker damage. The sapsucker damage will not immediately weaken the tree but monitor the health of the tree throughout the growing season. Prune out any dead plant material. Scratch the branches and look for green tissue. If you see it then the branches are viable.
See our website for photos and more information on sapsucker damage. http://extension.umd.edu/hgic/woodpeckers-and-sapsuckers
All you can do is keep the tree watered during dry periods to prevent further stress.
That makes sense. Many thanks. Next question is about the nearby boxwood that has wilting/browning leaves on the new growth - clearly not a sapsucker issue, but I don't want it to die. Suggestions? I'll attach a photo.
Your boxwood, like many others in our area, is suffering from cold damage. The plant probably had a lack of adequate soil moisture at a time when the foliage was beset by cold, dry winds. Such damage can also occur when there are wide fluctuations of temperature in a short period of time. Both of these conditions occurred in early spring.
No treatment is necessary. The plant should grow out of the situation as the growing season progresses. Be sure to provide the plant with supplemental irrigation during dry spells, especially in late fall before the soil freezes. If there is dead wood in the summer, simply prune it out.