If you have a little bit of spaghnum I'd mix that in with the bark mix to hold a little more moisture. It's been awfully dry and windy this fall, and they do like to stay pretty moist.
Mine plus the Miltassias and other similar ones are all under the mister section that gets watered every day here. Even with our cooler weather we've had this fall, it's been just enough to keep everybody happy because the wind dries everything out so quickly.