Crepe Myrtle problem
A crepe myrtle appears to be in trouble. Some leaves are yellow with brown spots. See photos. Some branches at top are blooming. Last year the tree had blooms all over. Last fall we placed sod in the yard around the tree. The tree is 30 feet from a bulkhead with brackish tidal water on Goldeneye Canal off of Manklin Creek off of Isle of Wight Bay near Ocean City , MD. Soil is reclaimed sand/clay from dredging the canal to create the land in 1980. Thank you.
A couple of issues come to mind for your crapemyrtle and the stress it may be under, and why it might not be flowering well this year.
First off, we are assuming that it gets full sun in that spot, so we can rule that out.
Soil is not a likely problem given how old the tree looks, but we do wonder if the rain in the last year and the watering of the sod has affected how well the ground drains, or if there has been any other changes to the topography that allows it to stay wet, because crapemyrtles do not like 'wet feet' so to speak.
Another possibility is that your new sod was fertilized which also fertilized your trees. If crapemyrtles (and most plants) are over-fertilized they can respond by pushing out a lot of green vegetative growth at the expense of flower production.
The yellowing leaves could be a sign of stress and early fall coloration, the harmless dropping of excess leaves, or of a fungal leaf spot called Cercospora, which is generally not greatly concerning. (https://extension.umd.edu/hgic/topics/fungal-leaf-spots-shrubs)
Lastly, check your mulch. Tree and shrub roots should not be mulched or covered any deeper than 2-4 inches, and should be pulled back from being in contact with the trunk or stems of plants.