When a houseplant loses most of its lower leaves, yet the top is still attractive, or again, it 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 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), all 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. Compare that to a stem cutting which, having been “liberated” from the mother plant before it has any roots at all, must fend for itself from the start.
Step by Step
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 upwards 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 three 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?
What to Do With the Mother Plant Afterwards?
A plant whose head has been cut off is rarely very elegant … and this is often the case of a mother plant after you’ve removed its cutting. However, if you want to keep it, it willquickly produce one or more new shoots just below the deleted head. It’s just that it will eternally look a bit off center.
Another possibility is to cut the plant back to the base, then chop the bare stem into sections about 3 to 6 inches (7 to 15 cm) in length, like so many small logs, then use them as stem cuttings. Many books and web sites warn that, in such a case, it’s important to remember which side goes upwards, because a cutting planted upside down won’t root and that is true, but … there’s an easy way of getting around this concern.
Simply plant the stem cuttings on their side, burying the bottom half in moist soil, but leaving the upper part exposed! Even from its prone position, the stem’s hormones will tell it to send new roots downwards and the new stem upwards! Soon each stem section will produce a new plant.