Violets are one of many plants that can be propagated vegetatively, without pollination, into a new plant by rooting a leaf cutting. According to the University of Nebraska Lincoln, whole leaf cuttings are one of the preferred methods for propagating African violet plants. Harvest leaves that are well-developed from a relatively healthy plant with a look you admire, as the leaf will produce a clone of the donor plant. Very old violet plants that are on their last leg can also serve as donor plants to save and propagate a favored plant.
Harvest a healthy, fleshy, robust leaf from the donor violet plant by severing the leaf at the top of the stem cleanly and on the bias. Leaving 1/4 to 1/2 inch of stem on the leaf is fine.
Fill a small nursery pot to within 1/2 inch of the lip with fresh, sterile and lightweight potting mix containing vermiculite and/or perlite.
Anchor the whole leaf cutting in the potting medium, burying the stem end up to where the leaf flares out, or roughly an inch. Firm the soil around the stem and base of the leaf.
Water the pot to make the soil evenly very moist but not sopping wet.
Tent the pot with a clear plastic bag, tucking the bag ends under the pot to create a makeshift greenhouse.
Place the tented pot in a brightly lit room where ambient temperatures remain between 60 and 70 degrees Fahrenheit. Avoid direct sunlight as this will overheat and easily kill the leaf cutting.
Transplant the cutting when it is well-rooted and a new leaf or two appear.