Propagating plants

Print pagePDF pageEmail page

Plants can be propagated by seeds, by cuttings or by air layering. Simply take cuttings, or “slips,” of the new growth and place them in a rooting medium. In a few weeks they are rooted and ready to be potted. Certain plants, however, are difficult to root from cuttings,these plants are successfully propagated by air layering. This technique also enables gardeners to rejuvenate plants that have become tall and leggy.

How to air layer a plant

by Linda Naeve

airlayering1Air layering is a procedure used to induce roots to form on a plant stem while it is still attached to the parent
plant. Partial girdling of the plant stem interrupts the downward translocation of carbohydrates and other
compounds. The accumulation of these compounds promotes rooting at the point of injury.
Materials: Sharp knife, toothpick or small piece of wood, Twist ties or cotton cord, 8 in. 3 20 in. sheet of clear plastic, Three to four handfuls of sphagnum moss, Water, Rooting hormone (optional).

  1. Air layering is done by first wounding the plant with a cut in the stem (figure 2). Make a slanting cut into the stem. The cut should penetrate the stem to about onefourth to one-third its diameter. Be careful to not cut entirely through the stem. Hold onto the plant above the cut so that it does not fall over and break at the cut.
  2. Keep the wound open using a small piece of wood such as a toothpick (figure 3). This is necessary to prevent the wound from healing over without forming roots. A rooting hormone can be applied by pushing it into the opened wound. The rooting hormone is optional, but it does promote more rapid root development.
  3. Saturate a couple handfuls of sphagnum moss with water. Squeeze slightly to remove excess water and press the moss into a tighter mass. Wrap the damp sphagnum around the wounded area on the stem (figure 4).
  4. Wrap a sheet of clear plastic tight around the ball of sphagnum (figure 5). Make sure none of the moss
    protrudes out the ends of the plastic. Use a large enough sheet of plastic to be able to go around the ball twice..
  5. Use twist ties or cotton cord to secure each end of the plastic snug around the stem, without injuring the stem (figure 6).
  6. Check the sphagnum ball every 7 to 10 days. If it has become light tan in color, it will need to be
    watered. This can be done by removing the top twist tie and pouring a little water on the sphagnum moss so that it turns dark brown in color. Examine the plant occasionally for root development.
  7. There is considerable difference in the amount of time required for roots to form; it will depend on the plantspecies. Some may form roots within 30 to 60 days, while others may require 6 to 8 months. When the roots have filled the sphagnum moss and are visible through the plastic, the newly rooted portion of the plant is ready for potting (figure 7). Remove the plastic and cut thenewly rooted plant off just below the mass of roots.Loosen, but do not entirely remove the sphagnum moss.
  8. Pot the plant in a container large enough to accommodate the root system. Use a well-drained potting soil mix.Water the plant thoroughly so that the excess waterdrains out the hole in the bottom of the container.

Prepared by Linda Naeve, former extension horticulture