Don't ship plants with lots of water. I've found success pulling them from the aquarium wet, laying them out by species, wrapping the bottoms lightly in paper towel, and lightly dipping the bottom inch or less of paper towel in aquarium water. Then you bag them up in Ziplocs, seal 'em tight with enough air so they don't get squished. Ship in a flat rate box--NOT an envelope--and if there's extra space around the sides, add in another plastic bag filled with enough air as cushioning, or better yet, wrap the plant bag in newspaper for cushioning and insulation.
Also, it'll earn you major points if you label each species. You can write on the bag in order of left to right if you take steps of some sort to make sure they don't bounce around and switch places. More simply, you can take a picture and label the picture in MS paint with each species, and send that to the recipient. You could include in the package a quick drawing reference labeled with each species if you're decent enough at that. You could get one of those little packages of different colored rubber bands kids use to make bracelets, and wrap them around the paper towels, so they're color coded and you can include a key. Really, there are a ton of ways to do this. But it earns you a ton of goodwill with your buyers if you take care to label things. It's pretty frustrating getting a plant pack and not knowing which ones should be near the light, which ones grow fastest, etc. Especially since you're having trouble ID-ing them yourself!
Last edited by myexplodingcat; 09-08-2014 at 01:17 AM.