Initially, a generous helping of mulch is the single most beneficial thing you can do for neglected, established trees. Apply a 2 to 3 inch layer in as wide an area as you are willing to sacrifice to the trees, but never up against the trunk.

If these trees were covered up with vines, etc., there may be some problems with sun scald in the upcoming months. Maybe even a severe decline due to injury.

I hope I'm getting this port in on time to be of some help...There are numerous factors to take into consideration with Dogwoods..Be it known, these trees are now suffering many disease problems which one needs to check into on existing trees. Check the over all appearance of the tree prior to making any mechanical adjustments of the specimen. The prior submission makes a valid point regarding sun scald..If the trees have been neglected and covered from ample sunlight, the possibility of sun scald can be a major issue.
The first attempt I would take to revive the trees would be to eliminate and significant sucker growth and also to tip back the entire foliage area. Cutting back will allow and encourage the tree to set a better root system, which in your case is priority.
Once a good shape is accomplished, I would apply a base feeding of a high phosphorous fertilizer, preferably a 5-10-10 or similar formulation..Fritted trace elements are also a great benefit in your case as well..Manganese, libdomum, boron, calcium etc will add to the over all vigor of the plants.
Again, Be well aware that florida species Dogwoods are now suffering various diseases such as anthracnose and root rot in significant numbers throughout the US and Canada.
At one time back in the 50's and 60;s the Merit Parkway was lined with these gorgeous specimens and today hardely one is left surviving.
Dogwoods require attention and in some cases, alternative trees are a better substitute.
The Kousa Dogwood is one species that is much more lenient in the maintenance department, but in your case, you are dealing with plants that are established.
I truly love Dogwoods and often times use them in my designs for obvious reasons, but a warning always goes out to the client of the possibility of future problems in health.
I wish you the best of luck in reviving these trees and if you are fortunate to bring them back, you will be well rewarded with the grandest display of spring color ever...If you have any questions further, please feel free to refer to my email posted on my blog at www.hortservices.blogspot.com Best of luck, and I hope this helps.

Here is a link that might be useful: Horticultural Services

Hi! Thanks so much for the suggestions! How do I tip back the foliage as suggested? I have no idea how to do this. I will do whatever I can to save them. They do have flowers popping out on them now its early march yet but I see flower buds starting and new growth actually popping up in the middle of the branches where there was no foliage so Im sure this is a good sign! Thanks so much for the help!

Following up...To tip off is a technical term professionals use to refer to hard pruning...By this I mean to scan the tree for elongated branches, suckers, and/or intersecting branches and cut them back, depending on tree height, about 12" from the tip of the branch. Be sure to cut at a node or a point where leaves are breaking out..If you have other questions, refer to me email address and contact me that way if it's easier...Chet

Good care plus the tincture of time.

When I moved into my current home there was a little dogwood growing not three feet next to a giant hickory. We had the hickory taken out for other reasons which then exposed a leaning, misshapen sad little thing- visible here dried up right behind the hickory.

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And now five years later- it is directly behind the birdbath and above that tiny speck of red.

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I have not done much in the way of pruning to reshape it figuring that it needed every leaf it had to support itself and recover. I mulch and feed some Hollytone very sparingly every year and make sure it gets enough water and that's it.
It is about ready for some pruning and while it will never be as beautiful as some of the layered canopy dogwoods I have in other areas the tree will always be special to me.
Just decent care and let nature do the rest.

If you're thinking that your Dogwood desperately needs sunshine - think again. It's an understory tree that needs the shade. If it gets too much sunlight or heat, it will be dead before you can say "princess of the forest"!

Thanks everyone for your posts and cearbhaill your little tree looks great! My tree is much bigger than yours and has very green leaves and is making an excellent come back now that we uncovered it from the tangle of vines it had on top of it. I am afraid to tip the branches since the last poster said they need all their leaves for energy. I am just taking good care of it and watering it and hoping she will once again find her glory.