Written by Kent and Joyce Stork
Published in the African Violet Magazine March/April 2002
Last reviewed/edited March 2020 by Joyce Stork
If you have never started a violet from a leaf cutting, it opens a new world of enjoyment for many growers. While some recommend spring propagation, leaf cuttings will root and grow any time of year.
You may use a leaf from a violet you already have or ask a friend to share a leaf of an attractive variety that you don’t have. It is common to find leaf cuttings sold at violet shows or by violet vendors. You’ll find that you can increase your collection without spending much money and have a lot of fun too.
WHAT VIOLETS CAN BE USED?
Most violets will come true from leaf cuttings. This means that the plantlets that grow will be the same as the violet from which the leaf was taken. They will, in fact, be clones of the parent.
Some violet hybrids will not reproduce true. Chimeras, which have a characteristic stripe of color down the center of each petal lobe, will rarely produce offspring with the same color pattern. Chimeras have a unique genetic structure which can only be propagated through side shoots (also called suckers) or flower peduncles.
Some hybrids have unstable genetic structure. Often, fantasies (violet hybrids with flowers which are speckled or streaked) or multicolor violets will produce a percentage of offspring that are not true to the parent. Some of the offspring may instead sport to solid color flowers. It is important to bloom-test (see these clones in bloom) before sharing them with others using the hybrid name.
Some violet hybrids are legally protected by copyright laws. These violets will usually be sold with a plastic stake which identifies the copyright restrictions on that hybrid. Many of these are violets that are sold by mass marketers, such as groceries and home stores. It is not legal to propagate leaf cuttings of these hybrids, except to replace the original plant when necessary.
GETTING THE BEST RESULTS
The most important rule for success is to use only very healthy, mature (but not old) leaves. Very old leaves will be more likely to rot in the first few months of the process. Older leaves often take much longer to produce offspring. This is a stressful procedure for the leaves, and only vigorous leaves will give good results.
If the parent plant has variegated leaves, choose leaves that are mostly green. The variegation is a genetic trait which will be passed to the offspring regardless, and heavily variegated leaves are far more likely to rot before any plantlets appear.
It is necessary to be patient. It will take about a month for a healthy leaf to produce some roots. Once that is done, the leaf will begin to produce tiny plants where the stem was cut. It takes a month or so for those plants to grow to the surface of the soil, and several additional months are needed for the plants to reach a large enough size to be separated. If the leaf is older, variegated, or was stressed, it may take longer yet.
Use a process which works well in your environment. This may take a bit of experimentation. Every grower seems to have a different trick that works well for them. If you have poor results using one method, try another. Leaves root and reproduce fastest at 72° to 80° F.
Finally, diligently keep the name of the parent plant with the leaf. Violet hobbyists value the name of their plants and will always pay more for a variety which is correctly named. Down the road, an unnamed violet (sometimes called a no-id) has little value to true collectors and cannot be exhibited in AVSA shows.
WHY DOES IT WORK?
When a cell of plant tissue is cut, a signal is sent to adjoining healthy cells to produce offspring. Usually, only one plant will grow from a cell when traditional methods of propagating are used. The injury to the cell triggers nature’s “survival of the species” reaction. When plant tissue is threatened, the plant uses any method available to guarantee that it does not die. This effort to survive is evident during many phases of the plant’s growth, but is especially evident when a leaf is cut away from the parent plant for propagation. Violet babies can occur naturally in some less predictable places. Occasionally, growers will find a tiny plant forming on a crack in a leaf, or at the very edge of a leaf which had a slight injury.
THE WATER METHOD OF STARTING LEAVES
The traditional way of propagating violet leaves is to place the stem into water until roots begin to grow. Using this method, select a healthy leaf and remove it from the plant by toggling it from side to side until is pulls free. Avoid pinching or bruising the leaf as this may lead to rotting.
Make an angled cut across the bottom of the leaf stem, one to two inches from where the stem meets the leaf blade. It is best to do this so that the angle of the cut section of the stem is facing up (the same direction as the top surface of the leaf.) This positions the future clones to grow straight up and in front of the leaf. If you wish to produce an extra-large crop of clones, slice up the stem about one fourth inch (so that the base of the stem is split) so that more cells are cut.
Choosing the container of water is one of the most discussed elements of the water method of starting leaves. Whatever container is used must hold the leaf blade safely above water while the petiole extends down into a water source. One old-time gardening expert recommended that a dark, long-necked beer bottle filled with water works well for this. She felt that the darkness inside the bottle was good for developing roots and prevents algae growth. But any container filled with water and covered with plastic wrap, foil, or waxed paper (often secured with a rubber band) will work. A hole is poked in the center of the cover so that the stem can be inserted through to the water below. Be sure to label the leaf with its hybrid name.
The water in the container should be relatively pure without softening agents or added fertilizer. If water quality is an issue in your area, it might be wise to use bottled water. Check the water occasionally to be sure that it is still clear and not clouded by bacteria or algae. If necessary, change the water. Watch the bottom of the stem for the development of tiny roots which will be slightly thick and white.
We would recommend that as soon as the roots are one-fourth inch long that you transfer the leaf from the water container and to a small pot of very loose moist potting mix which contains a high percentage of perlite or vermiculite. Water it in, and then set it in a bright location. The leaf may be covered with a plastic bag or placed inside a covered container (more on that later) while the babies begin to develop and grow.
Some growers prefer to allow the plantlet to develop while the stem remains in water. Surprisingly the clone tolerates being under water for some time. Some growers doing this then move the leaf cutting, with clone attached, and repot it carefully into potting mix so that the clone is just above the soil line. Others choose to remove the clone from the cutting and plant it directly into its own small pot.
THE SOIL METHOD
In the soil method, leaf cuttings are placed directly into the potting medium and allowed to stay there until the clones are separated. Growers who do this find it requires less effort, once the initial process is done.
Again, remove the leaf from the plant, avoiding any bruising. Make the same angled cut as before, leaving a stem which is one to two inches in length. If a leaf breaks off without a stem, the bottom fourth of the leaf may cut into a wedge shape which will simulate the stem.
Prepare a small pot, again using a porous potting mix. This may be only vermiculite and/or perlite, or it may be a peat-based mix with a high percentage of perlite added. Moisten the potting mix thoroughly and avoid packing it down as it fills the pot.
Insert the leaf, leaning it slightly backward so that the hairy top surface of the leaf is facing up. For best results, do not set the leaf into the soil very deeply, no more than an inch. The tiny plants must grow this distance to reach light, and they will be stronger if the distance is short. If you are opting to use the leaf with no stem, the cut edge should be set into the soil just enough to support the leaf upright.
Next, place the potted leaf into a clear plastic bag or container. We find that zippered plastic bags work well for this. Close the enclosure tightly. If using the bag, we find that blowing into the bag to puff it up works well. The added carbon dioxide in exhaled breath is good for plant growth, and the sides of the bag will be in less contact with the leaf. This step may be omitted successfully in climates which already have high natural humidity (50% to 60%) and warm temperatures. Be sure the leaf is labeled with its hybrid name.
Place the packaged leaf into a bright location out of direct sunlight. It will not need additional water so long as droplets of water are visible inside the package. If the leaf has not been packaged, it will need to be watered regularly. There will be no need to move the leaf or change conditions until the babies are large enough to be separated from the parent leaf.
WHAT ABOUT ROOTING HORMONES?
We personally find that it is not necessary to treat violet leaves with rooting hormone before putting them down. Violets are fleshy, allowing adventitious roots to form much more quickly on violet cuttings than other plant cuttings with woody stems.
The common method of dipping the cut stem into the hormone may result in a glob of the hormone on the stem. This excessive amount is more likely to burn away the new roots, and it may take longer to get results. Those who use hormone most successfully, dip a small dry paint brush into the powder and lightly brush an inconspicuous amount onto the exposed section of the cutting.
SEPARATING THE CLUMP
After a period of months, a clump of small clones will be formed at the base of the leaf. Each individual clone will have at least two leaves attached to each other at the base of the plant. While it is possible to transplant even tiny plants, it is generally best to allow the plants to grow until the leaves are at least the size of a dime before separating the clump. At this larger size, 4-6 leaves make up the rosette which is developing on each clone. It is easier for a novice to handle larger plantlets and easier to solve the puzzle of where the individual plants are connected among the tangled leaves. Some leaf cuttings may produce only one or two clones, while others may produce a mass of fifteen or more. Murphy’s Law seems to dictate that when you desire more plants, fewer plants will be produced.
We recommend slipping the entire clump and soil ball out of the pot and laying it sideways on a work surface. Gently begin working away the potting mix so that the stem of the parent leaf is exposed. Sort the small plants apart from one another. This is challenging to the beginner! The plants are reasonably sturdy, so one can be courageous about pulling them apart. A few torn roots will not impede their later growth. It may help to look for a distinctive neck that connects the rosette of leaves to the root system of each plantlet.
There are two common mistakes made at this point. Some will believe that each tiny leaf is a plant and literally pull the plantlet apart. This is a fatal error. The other mistake is to fail to separate the plantlets adequately, allowing two or more to be potted together as a single plant. This mistake can be corrected later, when it becomes apparent that there are two crowns competing for space.
Next, prepare the pots into which the clones will be transplanted. If the plantlets are small, a two-inch pot or even a 1” condiment cup with a hole works well. Fill the pot with loose, high-quality violet potting mix and do not pack it down!
Use the tip of a pencil (or similar tool) to make a small indentation into which the plantlet is set. It should be in the very center of the pot, and the stems and leaves should be above the soil with just the roots and the neck (if there was one) below soil level. Water each pot and set it in a slightly warm and humid location.
It may be helpful to place the transplanted clones back into an enclosure for a few weeks to bring plants through the shock of transplanting. At this stage they need filtered indirect light and prefer temperatures of 72° to 80° F. Be sure the violet hybrid name is transferred to the new pots. The young clones grow rather quickly.
As each plant grows and matures, it is likely to need a larger pot. Typically, the plants should be mature enough to bloom six to nine months after transplanting. At that point they should be in a pot which is about one-third the diameter of the overall plant.
GO AHEAD AND PROPAGATE
African violets have gained tremendous popularity since they were first discovered in 1892. Much of that acceptance is due to the ease of propagation. Starting a violet leaf is easy, fast, and inexpensive. Exchanging leaves with friends is a great way to build a collection.
Once you master propagation, you will find that you are no longer just enjoying the pretty flowers but becoming a capable grower who understands violets better. Some even believe that the plants they get from propagation are stronger than plants they buy – and more adapted to their own growing conditions. Leaf propagation also allows growers to produce one or more “insurance” plants to have if something should happen to the original.
Putting down leaves is the first step to becoming a skilled grower. Give it a try.