Ask Mr. Smarty Plants

We don't know which cypress you are referring to. There are 8 species of the cupressus genus native to North America, none of which are native to Florida. Of the three species of the taxodium genus native  to North America two, Taxodium ascendens (pond cypress) and Taxodium distichum (bald cypress) are native to Florida. 

We are also unclear in what exactly the dirt piled up around the tree involves. Did you do some grading, raising the  soil level by 3 feet in a large area? Did you just pile soil up around the tree itself at the trunk base? Either scenario could eventually result in the death of the tree. 

We found an article from Iowa State University Horticulture and Home Pest News, Tree Root Systems by Sherry Rindels, with information on the effects of dirt being on top of tree roots. Another article from the Missouri Dept. of Conservation, Tree Planting Breakthrough by Ann Koenig, approaches the problem with the idea that trees are often planted too deep. Your tree may have been planted at the proper depth, but is now suffering the same effects because dirt has been placed on top of the roots.

Since we don't know which tree you have, how extensive the layer of dirt is or why you chose to do this, we recommend that you contact a trained, licensed arborist and ask for his ideas on what, if anything, you can do to save your tree.