Walking Iris

Walking Iris (Neomarica gracilis) produces offsets which flower in the very early spring . When the offsets touch the ground they root, and in this way walk away from the Mother plant.This habit accounts for another name of the plant,Apostle plant. I grow them in pots so the offsets never reach the ground .The offsets can be taken off and set in pots and they readily root and  start growing. Information I have gathered suggests that they will live outdoor in zone 8, but the one time I tried them outside, they did not survive the winter.I have grown these for years and have forgotten where I originally got them although I do remember they were given to me. I have heard that there are yellow ones, but I have never seen any, except in pictures. (Google images is a wonderful thing!)