When I said "tropicals" I was referring specifically to tropical bonsai or trees/shrubs intended for bonsai. I have a couple of species of Ficus, a Serissa 'Kyoto Sport,' my daughter's elephant bush, and a few others. All (except the elephant bush) are woody; their native habitat varies in degree of wetness. So far, at least, I've managed to keep them all alive when I leave for a week or two. (Is it a cliche for a bonsaiist to quip, "Knock on wood?")