Question: I am new to propagating African violets. My question is: how long does it take for them to sprout? The leaves aren’t dying or anything, just sitting there.
Answer: How many plantlets a leaf produces, and how quickly it does so, depends upon a number of things. First, the age of the leaf. It’s best to use leaves that are mature, but not old. This usually means leaves taken from say, the third row. Leaves much older than this have petioles that are “tougher” in texture. If the petiole is hard or leathery, it will likely be slower to produce plantlets. Leaves that are too young also propagate less well. For this reason, it’s best to avoid using the undersized, “baby” leaves that appear first on a very young plant. We’ve found that plantlets can be removed from the mother leaf and individually potted anywhere from 3 to 5 months from the date the leaf was first put down.
Other factors are rooting medium, your growing conditions, and variety. Use a very light rooting medium, one that can be kept moist without rotting the leaves. Personally, ours is about 75% coarse vermiculite, 5% perlite, and the remainder sphagnum peat moss. Many growers use a mix of only vermiculite and perlite. In any event, keep it light and porous. Leaves also seem to produce plantlets more quickly when they are kept covered say, in clear plastic box or baggie. When doing this, be sure not to overwater the medium (damp but not soggy). Keep the leaves in a bright area (no direct sun) that’s neither cool nor warm–65f to 75f degrees is best. Too cold and they will develop very slowly, too warm and they may rot. As it is with most things, variety can also be a big factor. Some varieties just seem to propagate more quickly and prolifically.
A couple of final tips. Don’t cut the petioles too long and don’t bury them too deep. Most plantlets are produced from the cut end of the petiole. The further this end is beneath the soil surface, the longer it will be before plantlets appear. We cut them to about 1/4″ to 1/2″ in length, and root the leaf so that the bottom of the leaf blade is level with the surface of the rooting medium. It also speeds things along if the tip of the leaf blade is trimmed away. This keeps the leaf itself from growing and promotes more rapid root and plantlet development. Finally, add a little fertilizer to the rooting medium, though some might disagree with this. Our feeling is that every growing thing needs food. After all, we wouldn’t think of withholding food from an expectant mother or newborn