Whoa, hey, calm down buddy. I read your original post. I just couldnt figure out how you couldnt find a plant the barbs wouldnt eat... but...
I think I get it now. You have been trying aquarium plants in your pond, but your selection is limited at the lfs and the barbs mutilate everything you can find.
I think you will do much better at the plant store you just went to. I picked up all my pond plants at pond or garden stores, none at the lfs (no lfs' sell pond plants here.) If you havent, you should ask the storekeeper if they have other plants that would work for a pond, I think you will find that they have a lot, water features are becoming very popular. Plus, pond plants tend to be a bit thicker or harder than the plants commonly used in aquariums making them tougher to chew on.