Propagate wilmottianum in spring by pulling off basal growths. Works for me. Griffithi is better....glossier leaves but prob more tender. A penstemon, is it Joyce grenfell? Has wonderful true blue flowers too. Flosilverfairy, blue flax is about 30 cm tall, glaucous green foliage and delicate looking... Not sure if chickens will eat it. Can't see why they should though.