@bigemrg they are fantastic and don't mind part shade or heavy clay soil (both of which I have). This is one year old and is already bulking up nicely. I have two others now. Be careful, they're addictive 😉
@charlottejhurst oh dear. They tend to do best in damp conditions so maybe it needs more water. Mine gets the run off from the deck and seems to like it. Also, they're notoriously slow to establish so if it's a younger plant it may just need more time.