Cuttings should generally consist of the current or past season’s growth. Avoid material with flower buds if possible. Remove any flowers and flower buds when preparing cuttings so the cutting’s energy can be used in producing new roots rather than flowers. Take cuttings from healthy, disease-free plants, preferably from the upper part of the plant. Remove the leaves from the bottom node of the stem cutting. Usually, you can simply snap off the leaves. Make sure to retain at least three to four leaves on the stem cutting.
It is important to keep the cuttings cool and moist until they are stuck. An ice chest or dark plastic bag with wet paper towels may be used to store cuttings. If there will be a delay in sticking cuttings, store them in a plastic bag in a refrigerator.
As an optional step, apply rooting hormone to the trimmed end of the cutting and to the area where the leaves were removed. Many plants will root successfully from cuttings without the use of rooting hormone, but using hormone can speed up the process, and it might be essential for some hard-to-propagate plants.
To do a leaf cutting remove a leaf and include up to 11⁄2 inches of the petiole. Insert the lower end of the petiole into the medium/potting soil. The new off-shoots will form at the base of the petiole. The new plants can be then severed from the original cutting and the cutting may be used once again to produce more plants. Examples of plants that can be propagated by leaf-petiole cuttings include African violet, peperomia, episcia, hoya, and sedum.
For plants that don't have a petiole, such as plants with thick, fleshy leaves. These plants can be propagated by cutting the long leaves into 3- to 4-inch pieces. Insert the cuttings vertically into the medium. Mist every day/few days depending on humidity. From here they will develop root that will eventually push into the soil and begin to put off leaves. Some leaves will either produce roots and no leaves or leaves but no roots. As the new leaves start to bloom, do not be surprised if the original leaf begins to shrivel and die. This is completely normal and means your plant is growing successfully! Allow them to continue to develop but don't be surprised if they never grow successfully.
Wait until baby plant has a handful of leaves (ex: spider plant, 4 - 6 leaves) or has reached a size where it can survive on its own (for aloe, about 4 - 6 inches or 1/3 size of mother plant). Remove plant from mother carefully as to not damage other babies or the mother. Dig under and around a little bit and cut the pup out from the soil, making sure to get some roots. You can then place the pup in water to develop stronger roots or pot up right away if the root system is complex enough.
For spider plants, pilea, and the like, trim the lower leaves to ensure that just the stem and emerging roots will be submerged beneath soil or water. These stray leaves can rot and hurt the overall growth of the plant.
For aloe, cacti, and other succulents, let the pup dry out overnight and up to 48 hours to callus over. If they are directly placed in soil or water, they are more susceptible to rot and roots are less likely to develop.