It’s the bottom section on the leaf that forms leaves, which means that if you cut a leaf into three parts, be sure to always orient it so the bottom portion of each cut is the part that goes into the soil I forget the exact term, but its the portions closest to the center of the plant that are apt to grow more bulblets. The further away you get from the center, the less likely that the leaf sections will produce bulbuls. I know _ I making it sound more confusing!

It should work just fine without bottom heat. Just avoid colder than 50° F soil temps. I haven’t tried cooler medium, but it was worked at room temperature or under lights.

Thanks!

In April 2013 I was given 1 pea sized L Bulbifera and 2 tiny bulbils. I put them in a 3" pot on my kitchen window sill. In November 2013 the pea sizes bulb produced 2 leaves and 1 flower stalk with 3 coral red bells. The 2 bulbils each produced 1 leaf.
After the flowers died there were 2 black seeds which I put on the surface by their mother. There were also several bulbils. Now (Nov 2014) I have just separated them. The pea sized bulb is now cherry sized and growing strongly and there are 8 bulbils which I've planted around her in the same 3" pot with a little added compost. Very prolific!
I'm anticipating even more flowers to enjoy at eye level as I work at the kitchen sink!