redearslider.com

this might sound stupid but live plants can live in sand right? also what kind of plants are turtle safe

look on the main site, there is a list, and ur tutrle will probably eat the plants. and they can survive in just sand forever. but they can for a while

I grow plants in sand in my fish tanks. Near the bottom of this page shows some plants that are safe for RES to eat.
http://www.redearslider.com/plants.html

Like rsour said though, even if they don't eat the plants your turts will probably just tear them up for the fun of it

I've done pretty good with Anacharis. They are super easy to grow and don't need much (light and water). My two have gotten pretty good at leaving the planted ones alone. I'll plant about 15-20 strands and float 4 or 5. They'll eat at the floating strands but just hide in the planted ones. The minnows and guppies I have in the tank eat the crap out of the planted ones though. So far I've been lucky and they'll only eat the leaves and leave the stalks so they keep growing. Just have to break the strands down once they start growing again at the top.