Yellow spotty Holly tree
I have a large Holly in full sun that is having yellow spotted/mottled leaves on the west side. The East side of the tree and the new growth at the trunk appears healthy and dark green. I just moved back so I don't know if it was exposed to herbicides while I was gone but it was much more robust several years ago. The soil is clay ish but has decent drainage and has not had fertilizer or any treatment. I am in Cheverly, MD
Overall the tree does not look bad. It is not unusual for hollies to display a yellowish winter color. It is normal for hollies to shed their one year old leaves in the spring about the time the new growth is forming. Leaves may be yellow and have some fungal spots. Scratch the branches with your fingernail and look for green tissue. If you see it, the branch is still viable. If brown, it is dead and you can prune. Light pruning may be all that is needed and new growth should fill in.
Wait to see if the new growth is looking good to determine if any other action is needed.
We notice that there is lumber underneath the tree. Remove it so it does not affect the root system. Make sure mulch is no thicker than several inches and keep away from the base of the tree.