When a houseplant loses most of its lower leaves, yet the top is still very attractive, or has become so tall it threatens to pierce the ceiling, you can easily recuperate it by air layering. This is especially true with large indoor plants, like dieffenbachias (Dieffenbachia), rubber plants (Ficus elastica) and dracaenas (Dracaena), although this technique was used originally outdoors and on fruit trees, as air layering has been used in Chinese orchards for over 800 years.
Obviously, you could also simply cut the tops off these plants and root them, but rooting stem cuttings of such big plants is not always successful, especially with woody species such as the croton (Codiaeum) or one or other of the figs (Ficus) or scheffleras (Schefflera), which are notoriously hard to root. The advantage of air-layering is that the section you want to root continues to be nourished in minerals and sugars – and especially in moisture! –by the mother plant throughout the entire process. A stem cutting, having been “liberated” from the mother plant before it has any roots at all, must fend for itself from the start.
Air layering may appear complex, but is actually very easy to accomplish. Here’s how to do it, step by step.
1. Remove any remaining leaves at the spot where you intend to do the air layering.
2. With a knife, make a small incision angle in the stem, cutting upward at a 30˚ angle.
3. To keep the incision from closing too quickly, insert a match, a toothpick or a small stone. This injury sends a hormonal signal to the mother plant, telling it the time has come produce roots.
4. A light dusting of rooting hormone (use a Q-tip for application) may be useful for plants that are considered difficult to propagate by cuttings, especially woody plants.
5. Take a handful of moist sphagnum moss (soak it in water before use) and wrap it around the stem, over the wound. You need sphagnum moss, with long fibers, not peat moss, a more common garden product. Most garden centers offer small bags of sphagnum moss.
6. For this step, borrow an extra pair of hands, if possible, otherwise you will have to demonstrate fairly good manual dexterity and the ability to do 3 things at once. As your assistant holds the moss in place, wrap a sheet of clear plastic around it, attaching it top and bottom with twist ties, cord, or raffia.
7. Over the following weeks, the moss must remain constantly moist. You can easily tell when it is drying out: it turns light brown when dry. If necessary, therefore, loosen the top of the plastic sheet so you can pour a little water in, then seal it again afterwards.
8. Roots may be visible within weeks or not appear for months. In either case, when there are lots of them, remove the plastic wrap and cut the stem free just below the layered section.
9. Now just plant the rooted top in a pot of moist soil. The “baby” will immediately react, not as a cutting, but as a mature plant, since it is already solidly rooted.
That’s it! You just air layered your first plant. It’s not rocket science, is not it?