I have been on Dave's Garden for many years. I like it because it has information on growing each plant and pics, as well as the members' trade lists. You do not have to pay the subscription if you want to trade less than 3 times in a 24 hour period. I have never paid the subscription, and use the site for plant information all the time. Have traded from there many many times.

Also, if you are on Facebook, you can join pages there for trading. I'm a member of three, Seed Swappers Paradise Group, Plant Addicts Anonymous, and Seed Exchange. :)