I'm about 90 miles north and the poplar and blackberry are still blooming. The bees are definitely moving after the rainy few days we had. I'm praying for a good sourwood season.
Never underestimate your bees. I don't look any more at what is blooming to determine the nectar. Any number of seasons I have called the end only to find new wax and additional stored honey two weeks later. Most of those times I had no idea where the nectar came from. My rule of thumb is to wait until the second week in June. By that time....it is always finished.