We contacted the National Park Service with your query and Amy Genke, an NPS guide for the Natchez Trace, wrote to recommend that March to Mid-April are probably the best months. Obviously it's impossible to predict exactly when things will start blooming, but Amy provided the following notes from last year's prime blooms as a general guide: wild plum from Tupelo to the North End (March 14); redbuds in the Tupelo area (March 21); spring beauty, violets in the Tupelo area, dogwoods from French Camp south (March 25); redbuds and Chickasaw plum at their peak in the Tupelo area, dogwoods just about ready to bloom (March 27); dogwoods starting to bloom (March 29); crimson clover and wisteria in the Tupelo area (April 7). Hope this helps!