Andrew, I never saw your request for information on Hippeastrums here at the PBS forum but of course if I was too busy it is possible that I simply missed it. Here you can find great growers like Nhu, Jim Shields, Monica Schwartz. Mary Sue Ittner, Peter Taggart, just to name a few, some with immnese collections, that will share their knowledge (and valuable plants) in a most generous way. As for Hippeastrum mandoni it grows in the typical lateritic soil, poor, acid, high in iron content. It drains like a sieve. You must grow it hot as temperatures are critical in obtaining a fatter bulb each year. Even during its long winter dormancy it must be kept in a warm spot. Rainfall in the wild arrives in late spring and lasts until mid Fall. A common mistake is to start watering at the slightest sign of Spring weather, this is a wrong as the plants go through a period of dry warmth before "waking up". Bulbs must be actually planted deep, as in the wild, not kept half buried. You never find them this way unless the slope went down from a landslide.During the growing period they are HOT, you can grow (and harvest) bananas in those regions.Half day direct sun does not harm althought they grow in dappled shade in most cases.