> What are the hardiest species, and how cold are people growing > tropaeolums? Which are most tolerant of moisture during winter? > > I live in nominally USDA zone 6 (NW Arkansas), with bouts of zone 5 (-20 > F/-26 C overnight). As usual, there are unexpected survivors, some with > the help of friendly microclimates (Gloriosa superba, for instance), some > just much tougher than the books say (the zantedeschias, alstroemerias). > > But the ground never freezes deeply or for long, and so things with nearly > any degree of hardiness which like to be planted deeply stand a good > chance if they'll tolerate winter moisture. I have grown Tropaeolum tricolour for 2 years, in a pot on the bench, in an alpine house that only occasionally goes below freezing. It looks a bit lack lustre after a cold night but no damage so far. T. polyphyllum I also have in the garden (in pots). Some survive some don't; I suspect too damp rather than cold, or a combination of the two. T. pentaphyllum survives in a pot against the south wall of the house, but as it is in leaf all winter only flowers some years depending on the state it is in by spring. I am told sandersonia will survive in a sheltered spot, but cannot confirm as I only grow it frost free. Similarly I have only tried littonia frost free. My pot of T. tricolour won an award this year in our local AGS group show, as the members choice of best in show, but was ignored by the visiting judge, as he did not consider it to be an alpine. Remembering that the definition of an alpine or rock garden plant, for AGS shows, is "one suitable for a rock garden of moderate size, or an unheated cold frame or alpine house, and which will survive an average winter in the area in which the show is held". Who knows what entries will be seen in the future. Brian Whyer, zone 8'ish, Buckinghamshire, UK