Rooting leaves in water is one of the more traditional methods of African violet propagation dating back to the early days of the plants’ popularity in North America. If your grandmother grew African violets from leaf cuttings she probably used this method (or merely pinched off a leaf and stuck it in the soil of the nearest house plant).
To root leaves in water you will need a rooting container to hold water and a means of suspending the leaf above the water while the stem remains in the water. We like to use small, colored glass bottles (colored glass slows the growth of algae) and aluminum foil. Cheap and easy.
First, choose a healthy, firm leaf from one of the middle rows of the parent plant. Make sure you choose a leaf with a long enough stem (petiole), preferably 1-1/2 to 2 inches long. Cut the tip of the petiole at an angle with a sharp blade.
Fill the rooting jar with water to just below the rim and cover with aluminum foil. Poke a hole in the foil large enough for the leaf stem. Large leaves or longifolia leaves may require additional support. If you will be using leaf supports, such as coffee stirrers or plastic plant tags, you’ll need to make openings for them as well.
An alternative to using additional leaf supports is to create support from the aluminum foil covering the rooting jar:
Monitor the water level in the rooting jar daily to make sure the stem is sufficiently covered. Plantlets should begin to grow and become visible along the stem within a few weeks.
This is a leaf of African violet ‘Cherry Dots’ showing several babies growing from the stem after approximately 3 months in water.