I have started to realize how important it is to just ask for sustainable clothing, even if you are pretty sure a place doesn't carry it. First of all you can be surprised, many places are experimenting with carrying some organic options. Sadly they are often hidden and mixed in with everything else. Asking can often be a way of "training" the salesperson to understand what organic or sustainable is. I have been met by many a salesperson that asked me if "organic is a brand?" Until the sales staff is asked, they often won't bother to learn anything about it. I have also been in the situation where one person is aware that they carry a sustainable item and another isn't, it lets the store know that they should inform their whole staff on the sustainable options. Be sure once you ask you double check the tags yourself, I have also been told things are organic when really they just meant that they were cotton.
So while you're asking, you can ask the staff at Nordstrom to steer you towards these:
I love the World Wildlife Fund's hotter than I should be shirt, although I am not sure if I have the nerve to wear it. It is a great message, a little sassy, and bound to start conversations. A nice balance between the eco doomsayer tees and flowery eco hippy tees. I must admit I have a few of both. I saw these tees at Nordstroms and they are very soft and nicely cut.