I took one Rex begonia leaf and used florist pins to anchor it to the soil in a 6" pot. It grew several babies along the veins.

How long did it take those to get to that stage in the photo?

A few weeks to get to that stage in that photo. The beauty of this is they can stay fairly small for months if you choose to not pot them up - just keep them from drying out completely and with a cover over them you rarely have to water them after the initial wetting of the pellets.

Here is one where I used the entire leaf in a blueberry container (perforated holes top and bottom). The leaf is from Alligator Alley (Greg Sytch hybrid). I used a technique that Mike Flaherty described earlier this year where you keep the petiole as long as possible and bury it horizontally about half an inch or so. He said babies pop up along the entire petiole but in this picture it is only at the cut end (so far).

I started over 300 last year and potted them up later in the year and due to that fact, I lost several. (neglect on my part). Here are some of the survivors that were potted up to 3 inch pots last year. This photo is from late September this year. I think there are four pans of starters in this photo. I can fit 18 three inch pots in these aluminum pans. I punch holes in the bottom of the pans for drainage and when I take them indoors for winter they go simply fit into the same size pan with no holes. Makes caring for them a lot easier.

This is the original poster- but i am using a different account.
I dont understand...
When you put the petiole in the soil, do you have to make sure that the leaf does not touch the soil?
And will the new plants always look like the original plant you propagated?
And if you do it with a wedge, how do you cut the leaf?
so you just cut it in half and stick it in moist soil?

I really want to make babies with mine.

see link ... even a video

ken

Here is a link that might be useful: link

Depends on the leaf and how wet the surface of the soil is as far as the leaf touching. Some rot if it is too wet and the leaf is fleshy. Others dry up if the humidity is not kept high and the soil kept somewhat "wet". You just need to experiment and find out what works for you. You have to kill 1000 or so before you get the hang of it. Just kidding on how many you have to kill (but there is some truth to it as well).

Wedge cuttings are like dividing a piece of pie except you want a major vein kind of in the middle of each wedge piece. Here is a photo of wedge cuttings. This is a 72 count tray.

And a close up of a few of those. I had so much luck with this method that I started 4 more 72 count trays and a few 36 count trays as well. VERY EASY...

Im gonna have to try this.
Free plants!!!

Go for it. Remember you will eventually have to pot them up to bigger and bigger pots. I did wash my leaves in a soapy bath, rinsed and dried before sticking them. Hoping to get rid of most of the germs before sticking them. Not sure if that is really needed since others I just stick in almost anything during summer without much fanfare. Some rot but some make new plants. The pellets I poured hot water on them to hopefully give them a little sterilization. Again probably not needed. Let cool before sticking if you go with the hot water.

Here is a bit fancier mini-greenhouse that has a reservoir and a water wicking mat included. The plants are too big to use the cover on now so I need to pot them up before I lose them all.

Hello I have done a video explaining 3 ways to propagate rex begonias here https://youtu.be/KQu_H3Yroa0 hope you enjoy