Here's an interesting event - an LA garden tour of great gardens that use at least 50% native plants:
http://www.theodorepayne.org/Tour/tour.html
Oh, and Dphile: the other option available to you is to have your embroidery done on a separate piece of cloth, then sew the cloth onto the chair back (which in theory could even be done by hand if necessary). This has the added benefit of no backside of embroidery being visible.