Propagating african violets is very simple and lots of fun. They propagate quickly and don't need much to do it. One leaf can give you from one to many babies that will become beautiful plants. Its also a great school project for children.
There are many many ways to propagate. Below I have explained my way to do it. This way works fine for me, I am sure you will find the best way for you. If something works for you, please don't change your method, we don't like to fix things that are not broken.
First you need to cut a leaf from a plant, the leaves from the 3rd row are the best ones for the job. You count the rows of leaves starting from the center. One row should have 3 leaves therefore the 7th, 8th and 9th leaf from the center should be good candidates for the job.
Plant the leaf in a light mixture. You don't want to damage the angle cut of the stem by forcing it into the soil because this is where the plantlets will grow so I like to use a pencil to press a hole into the soil and then put the stem in the hole. Lightly press the soil around the stem to hold it in position and don't forget to mark the leaf so you will remember the name.
You can either place one leaf per container or many leaves together. The choice is yours. Do not fertilize the leaves in the first weeks. The leaves do not have roots to receive the fertilizer. I usually give them a very light fertilizer after 3-4 weeks, by this time, some roots will have grown for sure.
IT IS CRUTIAL THAT THE SOIL DOES NOT DRY OUT AT THIS STAGE, the leaf doesn't have stored energy to live on without water. The soil MUST be kept DAMP but NOT WET, if it is too wet, the stems might rot.
You can bag the pots if you like but if you do, you will have to gradually open the bags to let the plant get use to its new and dryer environement. Bagging a plant helps it keep a higher humidity.
In this photo, you can see the babies popping up beside the stem. You will be the judge to decide when it is the time to seperate the babies from the mother. You do this when you feel comfortable working with the size of the plantlets. The time it takes for leaves to make babies varies from one leaf to another. Normally after or 4 months, sometimes sooner, you will see some little leaves piercing the soil.
When you are ready to seperate the babies, delicately take the leaf and babies out of the pot. I like to use an exacto knife to cut off the babies. Try to cut so to leave some roots on the babies. Then delicately plant into a nice light mixture and don't forget to nametag the plant. You can replant the leaf, it could produce new babies
So you see, there isn't much to it. I have tried to explain as clearly as possible the how to do this but if you should have other questions, please feel free to contact me, it will be my pleasure to help you. firstname.lastname@example.org