Hello Gordon, I am so happy to read this email from you, as it means I am not completly crazy, to do such experiments mysef with Hippeastrum. I have a very similar experience, however I will say this: most hybrids will substain temps hovering over the freezing point, some will survive temps even down to -12 C. Of course, in certain conditions. In this case, I find the most important is the humidity, especially in soil. If one experiments with Hippeadtrum in zone 9a and bellow, best is in completly dry soil! This either means in a an unheated greenhouse or to a house wall, where it does not rain at all! Snow in this case would be beneficial, but with the climate change we all experience recently, the permanent snow cover has become a long distant dream. So I suggest got for it, try various things, learn. And most important,fFollow your intuition! Most hardy for me have proven to be H. papilio, H. aulicum, xAcramanii, Exotic Star, most Rascals, La Paz, Evergreen and you will laugh, Chico too. All survived short temps down to -12 C, here in Berlin. And not just one winter. Yes, they were completly dry and not exposed to winds or any rain. Most bloomed in 2nd half of May, when it warms up here. Good luck, Vlad On Tue 16. Nov 2021 at 18:48 Gordon Hogenson via pbs < pbs@lists.pacificbulbsociety.net> wrote: > I grow Lilium species and have no difficulty finding cultural requirements > for almost all species that I have come across. Not so with Hippeastrum, > although some great resources exist, such as the Bulb Maven blog and the > PBS Wiki. > > Well, the Hippeastrum in Bolivia book is inspiring and has prompted me to > add some new species to my collection. My Hippeastrum growing is mostly > limited to indoor spaces, but I do have some limited greenhouse-like spaces > that is usually not heated. I'm in zone 7b in Washington State. > > I've always been interested in pushing the limits of hardiness, but with > rare and expensive bulbs, I hesitate to do any experiment that would risk > the loss of the bulb. However, information available says that, for > example, H. papilio is hardy down to -7C (from a scientific study). > > The Hippeastrum in Bolivia book includes a table that indicates which > species are present at the highest altitudes, which would be an indication > of their hardiness. H. cybister is said to grow at over 3000 m and the list > of Bolivian species growing at over 2000 m contains 18 species. One can > look up the climate in La Paz, Bolivia and find that average lows are just > below freezing, so clearly H. cybister from these areas must be quite > hardy. > > It is clear that the genes exist for hardiness in Hippeastrum. Hippeastrum > hardiness was discussed previously on the list, and many people had success > growing hybrids outdoors in marginal zones, as long as the bulbs were > planted near heated buildings. Others tried deep burial and deep mulches to > protect bulbs in winter. > > I have tried the so-called "hardy amaryllis" that are sometimes available, > hybrids such as the Rascal series of Sonatini types sold by Breck's and > others. Names include Red Rascal, Pink Rascal, Balentino, etc. Also, > Hippeastrum x johnsonii (St. Joseph's lily) is fairly hardy outdoors in the > South and has persisted for many decades as a heirloom pass-along plant in > zone 8 and maybe into zone 7? I found that most of these bulbs did > overwinter outdoors for me in my climate. However, performance in the cold > temperature was not great. Emergence in spring was very late and slow in > the cold soils. Foliage also suffered in the cold spring rains. The > emerging foliage also suffered from the depredations of slugs and snails. > > But even so, I did get blooms and was able to collect seeds outdoors from a > cross involving red hardy amaryllis and Hippeastrum x johnsonii and have > raised those seeds almost to blooming size, although because of the > difficulties the plants faced outdoors, I am only growing them in the house > now. > > However, I think that some of the "hardy amaryllis" Sonatini types are not > thriving indoors, and actually need more of a cold period to do well. > Hippeastrum x johnsonii has bloomed indoors for me, but not consistently. I > suspect it needs the cold period to flower best. My next step is to move > the "hardy amaryllis" to a mostly unheated greenhouse and see what > happens. I suspect that this would also be a good environment for H. > cybister and other higher-altitude species. The space is not completely > unheated. I have a thermostatically controlled heat source, an electric > heater plugged into a "thermo outlet" of the type available in hardware > stores and designed for heaters to prevent pipes freezing. It comes on only > around freezing temperatures. I use this space to overwinter Liliums as > well whose hardiness is in question. The advantage of this space for > Hippeastrums like cybister is that they could be kept dry, consistent with > the dry winter of their Andean home. > > I eventually hope to set up a passive solar greenhouse, another mostly > unheated structure with lots of thermal mass and insulation. Maybe an ideal > environment for further experiments with pushing the limits of Hippeastrum > hardiness. With patience and persistence, it should be possible to breed > hybrid strains adapted to such conditions. > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > http://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> > _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>