The black stained look is on the glossy side of the leaf. Only a small speck or two show on the back side of the leaf. The leaves are falling off. The berry buds and flowers are plentiful. The weather has been erratic with heat in the 80s this past week. We have not had a deep cold spell for a while. The tree is in the center of our recently replaced deck. I would also like to know how to keep it healthy. Thanks for your help.
Carol
This sounds like either tar spot or sooty mold. Sooty mold is normally a result of a pest infestation. These articles will help: https://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-problems-holly-leaf-spot-or-holly-tar-spot.htm
https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
Neem oil can be used to treat both. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
My four year old female holly bushes are not looking so good after I took the winter tenting off of them. There seems to be a lot of dead leaves, over most of the bush. . . . are they completely dead? Should I prune off all of the dead leaves (which is most of the bush?) Any suggestions?
Yes, you can prune out the dead growth. In fact, you can cut the plant back by a third of its growth to help rejuvenate it, though this will affect berry production but if it's looking poorly anyway, this shouldn't be an issue right now.
We have two new holly bushes, which were planted last year, that are showing signs of distress. Some of their leaves are turning yellow, and my wife has noticed a large number of flies and bees on its blooms. Do you have any advice on the problem?
If you have had a lot of rain and the drainage in the area is not good, it can cause problems with leaves. Is the ground swampy? If the ground stays wet, the roots can't "breathe" and falling leaves or yellowing would be a sign of this. Too much water causes iron chlorosis. This article will help you fix the problem: https://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-yellow-leaves.htm
The insects are likely visiting for pollination.
I have two holly bushes within 3 feet from each other. One is doing wonderful and the other one is thin and has a lot of dead branches. The first one is full and beautiful and healthy. What is the difference? Can I prune the dead branches?
The second one that is not doing well may have a fungus or pests (or both). You can remove the dead branches, but I would treat the plant with a pesticide and a fungicide to treat both possibilities. I personally like neem oil as it is both a pesticide and a fungicide and is organic.
What can we do to fix the problem?
If you have had a lot of rain and the drainage in the area is not good, it can cause problems with leaves. Is the ground swampy? If the ground stays wet, the roots can't "breathe" and falling leaves or yellowing would be a sign of this. Too much water causes iron chlorosis. This article will help you fix the problem: https://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-yellow-leaves.htm
I have roots sticking out above the ground and need to do something to lower or remove them. I don't want to kill the tree if I can avoid it.
This article, which would apply to shrubs as well, should help with suggestions: https://www.gardeningknowhow.com/ornamental/trees/tgen/exposed-tree-roots.htm
The other night it we got frost and the new growth of my holly bush has turned brown. Should I cut the tips off or leave it alone? It looks like just the new growth has been affected.
Yes, new growth is much more cold tender than mature growth as it has not had time to toughen up. If it is brown and the stems are brittle, then you can remove it. If the stems are still pliable, I would leave it as it may still regrow leaves.