From our rooted perspective, we perceive propagation not as a technique, but as a fundamental expression of life. To create a new petunia from a piece of an existing one is to engage in a most ancient and reliable form of renewal. Here is how you can help us achieve this.
Choose a healthy, non-flowering stem from the mother plant. A stem that is actively growing but not yet bearing the heavy energy cost of flowers is ideal. We direct our energy towards root production more readily from these younger, vegetative parts. Using a sharp, clean blade, make a clean cut just below a leaf node (the point on the stem where leaves emerge). A length of 3 to 5 inches is sufficient. Immediately place the cutting in water or a damp paper towel to prevent air from entering the vascular system and forming an embolism, which would block the flow of water.
Gently remove the leaves from the lower half to two-thirds of the cutting. This is crucial. Any leaves buried in the rooting medium will rot, creating conditions for fungal diseases that can kill us. You may also pinch off any flower buds. While beautiful, they divert precious energy away from the critical task of root formation. If desired, you can dip the cut end into a rooting hormone powder or gel. This is not strictly necessary for our kind, as we root readily, but it can accelerate the process and encourage a stronger, more robust root system.
Plant the prepared cutting in a small container filled with a lightweight, well-draining, and sterile rooting medium. A mix of perlite and peat or a commercial seed-starting mix is perfect. It must hold moisture but also allow for oxygen to reach the developing roots. Water the medium thoroughly until water drains from the bottom, ensuring it is evenly moist but not waterlogged. Then, create a humid microenvironment for us. Cover the pot with a clear plastic bag or place it under a humidity dome. This dramatically reduces water loss through our leaves (transpiration) while we lack roots to take up more water. Place us in a location with very bright, indirect light. Direct sun will cook us inside our humid enclosure.
Within 7 to 14 days, under the right conditions, you should feel slight resistance when you give the cutting a very gentle tug. This indicates that roots have formed and are anchoring us in the medium. You can gradually begin to acclimate us to less humid conditions by opening the plastic bag for longer periods each day over the course of a week. Once the root system is established and new top growth is evident, we are ready to be transplanted into a larger pot with a standard potting soil mix and treated as a mature plant, ready to continue our growth and eventually produce a magnificent display of flowers.
