"Propagating the Indoor Oasis"This is a continuation of the indoor oasis series, the first two installments of which, were posted on March 17th and 19th. By Deb Lambert
Depending on your locale, you may very well be engaging in the first gardening chores of the season, while continuing to tend that indoor oasis. It's often at this point, that overgrown indoor specimens demand our attention.
Rather than severe pruning that leaves unsightly stumps, or treating such large-scale prunings as cuttings (a risky proposition, at best), consider performing an air layer. While some of the larger foliage plants with which we accent our home interiors, may have become overgrown and leggy, this becomes the ideal way to handle the pruning. At the same time, we gain a young, healthy, well-rooted plant to add to our collection or give to a gardening friend.
An air layer is a method of inducing the top portion (one or several stems may be air layered at the same time) of the plant to produce roots, while still receiving sustenance through its root system. Suitable specimens for this method of propagation are schefflera, dracena, yucca and ficus, including weeping fig and rubber plant. At a point where the main stem is still somewhat green, usually about 10-20 inches back from an actively growing tip, is the best place to attempt an air layer. Select an area immediately below a leaf or leaf scar. Place a small bamboo stake (about one foot long) alongside the area to be cut and secure it, above and below, with twist ties. This will act as a splint, preventing the air layer from snapping off before it's rooted.
The materials you need for this operation include long-fibered sphagnum moss (soaked in warm water), rooting hormone powder, artist's paint brush, a sharp knife, plastic wrap and more twist ties. Make your incision, at the aforementioned point, along the stem. There are two acceptable methods of cutting into the stem. Girdling the entire stem, by cutting into the inner wood, will often stimulate root production. The other way, which I've found most successful, is to cut out a notch on one side of the stem, which extends about 1/3 of the way into the inner wood. This becomes a very weak point, which is why that "splint" was so important.
With a small brush, dust the cut surfaces thoroughly with the rooting powder. This will hasten root production and guard against possible fungus problems. After wringing excess moisture from the long-fibered moss, pack it into the cut and form a ball of sphagnum around the area. Wrap the ball with plastic, tying off above and below with twist ties.
Check the moss several times weekly for moisture, sprinkling lightly, if needed, then replacing the top tie. After about six weeks, you should notice small, white roots expanding into the moss ball. Your new plant should be ready to stand on its own. Sever it just below the moss, remove the plastic and pot it in a loose, well-drained potting soil, adding a small stake for stability.
The stump you leave behind can be re-trimmed to a more appropriate point, just above a leaf or leaf scar, from which new growth will eventually emerge. December-March are ideal months to attempt an air layer. If you wait until indoor plants become more active, in April/May, the incision may heal over quickly, without ever producing roots. I've experienced this several times, while trying to root a rubber plant.
By making an incision, you literally shock the plant into trying to propagate itself, and so, roots are produced. While actively growing, the sap flows freely and the plant's ability to heal a mechanical injury is greatly increased; hence, the increased failure rate of air layers performed on indoor plants, during the growing season. However, an air layer can be a very successful way of propagating some of our woody ornamentals in the spring... rhododendrons and azaleas respond well.
Soil layers (also suitable for woody ornamentals... more about these, next time), cuttings and seed starting are the other means at hand for increasing and propagating our favorite plants, and for maintaining an attractive indoor oasis. Get the whole family involved in these fascinating projects.
©Deb Lambert 2008
Manchurian Azalea / Azalea mucronulatum*
Snow Fountains Weeping Cherry/ Prunus x 'Snofozam'
