The Tennessean's consumer columnist has all the details about this year's free Gardenweb plant swap held in Hohenwald, TN.
If you go, don't forget that you aren't too far from either of the two Mennonite bulk food stores, as well--one between Hohenwald and Summertown, the other just outside Lobelville.
If you like to camp, you can take advantage of free rustic campsites at Meriwether Lewis National Historic Site just off the Natchez Trace (just a few minutes from the first Mennonite store).
We have also camped at the secluded Mousetail Landing State Park on the banks of the Tennessee River (closer to the 1-40 exit and the Cane Creek Market). Sounds like a fun weekend trip for someone who's not this pregnant!