I too will join the fray. I planted my first mature Veltheimia capensis bulbs with half of the bulb exposed when I lived in a very hot climate with summer temps over 100F for three months. By the end of the summer you couldn't see any of the bulbs. How? I don't know, but I don't think the physics is against it. If you tried to punch through asphalt with a shoot of a plant you couldn't do it, but plants frequently are able to do this amazing feat. Taking a bulb and pushing it into soil is very different from a bulb pulling itself deeper. I am sure there's someone who knows all about the physics of hydrostatic pressure, which has something to do with this. Diana Telos