Thanks Ann, I didn't know about the Hosta virus, I'll check it out with the sellers. Thanks for the weblinks Ann and Susan, very helpful.
Susan, I keep thinking of zone 8a as a really cold zone, because in Australia there are few places people live that are colder. Although we are cold enough here to not need to grow low-chill stonefruits/berries and Dogwoods flower every year, I forget there are plants from much colder places still. I suspect that the really low chill Hostas are not readily available in Australian nurseries though. There is not really a comparable product to Milorganite in Australia. Our problems are kangaroos and rabbits. I can tell you the wastewater from our septic doesn't deter either of those animals! Deer are a feral animal here, but haven't reached this area yet, though they seem to be moving closer all the time. Just a few days ago I photographed some just over an hours drive west of us! Thanks for your suggestions, I've had my eye on Paradigm and Guacomole, very interesting!