Sometimes rooting begonia leaves can be very slow. A lot of that depends on several factors such as the health and age of the leaf, rooting conditions (soil, temps, humidity, light, etc.), and the season you start it in. I think I read somewhere that summer and fall are the best times to root a lot of rhizomatous begonias (rexes fall in this category).

Anyway if you got it to root, it could sit there for the right conditions to pup. I had rooted a beefsteak leaf in fall a couple of years ago and it didn't do a thing all winter but it didn't die either. Then in spring it finally started throwing up some small leaves. Talk about slow. I bet it was six months before it threw up some new leaves.

Now I root most of my leaves by water rooting and always tent them with a plastic cup or plastic bag. I have several in the basement now that have rooted in a week and are ready to be potted in some soil.

Then there are the oddballs. I rooted 'Lalomie' by water this summer and let it sit in the water for a couple of months until it had pups at the cut stem sitting in water. I finally potted it up and it is slowly growing. In the same glass of water I rooted two 'Martin's Mystery' leaves and stuck them in a cookie jar the same time I potted up the 'Lalomie'. The cookie jar is full. Go figure.

Then I put four leaves of 'Lalomie' in the same glass as the first leaf (I cleaned it out first) on Feb 22. I see it now has some small pups at the sinus of two leaves and all 4 stems have some roots. That is slow but it beats rotting or drying up and blowing away.

My best results now are from water rooting for most leaves. Some varieties are so easy to start by leaf that sticking them almost anywhere will root (that includes gravel, sand, Perlite). The two easiest for me have been 'Joe Hayden' and 'River Nile'.

My latest experiment is 'Pink Diamonds'. I put four leaves in water, four in Perlite, and eight in a big aquarium with some on the edges of the aquarium where it is wetter, and some in the middle where it is hotter and drier. This way I can see which is better for this variety.