I would be interested in the answer also

Hello,

Leaf must include the lower "collar" which contains the most meristem cells.

Please take a look at the following post for a response:

http://forums.gardenweb.com/discussions/1794449/gasteria-leaf-propagation

thanks, I had forgotten about that post. Food for thought!

Gasteria leaves do not need to have the collar attached to produce new plants. The whole Gasteria genus is adapted to grow from leaf pieces after grazing by native animals. When Ernst van Jaarsveld sent me his 'cultivars' in the 1990s many were leaves sliced off with a knife. All grew & most produced many plantlets from the base. The thing is a leaf can root & live for quite a long time.....sometimes until the next season before making its new plants. Also the use of rooting hormones is utterly unnecessary in propagating Gasteria. These plants are designed by the 'great Spirit' or who ever it was ;) to grow roots & new plants from leaves & all they really need is to land on the ground to succeed. In his original book van Jaarsveld stated that G.rawlinsonii was the only species that did not proliferate from leaves but he soon got reports from all round the world that leaves of this species were not only rooting but making lots of new plants. I have pots with many G.rawlinsonii propagated like this. Now Haworthis are a different story & they root & grow new plants better with the base attached though many will do it from cut leaves & some will even grow from root cuttings. As far as I know the other main member of the family, Aloes simply wont grow from leaves at all. Here is a picture of a Haworthia truncata root cutting after one year: