There are a lot of misconceptions and much misinformation flying around regarding Bletilla species and hybrids. They are indeed much hardier than generally supposed and also thrive in full sun here in SE Pennsylvania. They are often touted as obligate shade plants. In our zone 6b garden (minimum recorded by us was -2F) we have about a dozen clumps of various striata leaf and flower variants and the older hybrids (Yokohama, Coritani etc.) which number hundreds of shoots per clump, and thousands of flowers. Clumps are a couple of feet across and very dense. The colors are very intense. They set seed regularly but I haven't seen any seedlings yet. I also have in the garden smaller clumps of the newer hybrids of the "Penway" series and they are also reliable. Of the other species, B. ochracea seems fine, B. szetchuanica (sp?) faded away but that maybe because it is much smaller and less vigorous anyway. The noses of these plants are not far below ground and I have failed to mulch them at all in the past couple of years, which have seen cold winters. In late May and early June the Bletillas make a spectacular display, early in their season the large clumps of Iris tectorum they are intermingled with complement them very nicely. I'll be uploading some of this year's pictures to my web site when I get the chance. Best, J.