Print This Page

Air Layering Plants



Air layering is a useful method of reproducing plants by producing roots on the stems of shrubs, trees and indoor landscape plants. This method, developed centuries ago by the Chinese, has been used successfully as a mean of propagating some of the more difficult-to-root plants.

The procedure is to wound the stem or branch of a plant and enclose the wounded area with a moist medium until roots develop from the wound.   Success is dependent upon keeping the rooting medium moist until the roots are formed and large enough to support the new plant.

Woody plants frequently propagated in this manner include magnolia, holly, camellia, azalea, Japanese maple and many of the fruit and nut bearing plants such as citrus, apple, pears and pecans.

For best results make air layers in the spring on shoots produced during the previous season or in mid-summer on mature shoots from the current season's growth. On woody plants, stems of pencil size or larger are best.  Thicker stems on the more herbaceous plants.

Steps for making a successful air layer are as follows:




1. For wounding woody plants such as magnolia, gardenia, rose, fig and similar plants make two parallel cuts about 1 1/2 inches apart around the stem and through the bark and cambium layer. Connect the two parallel cuts with one long cut (a) and remove the ring of bark (b), leaving the inner woody tissue exposed (c).



For wounding plants having less woody stems:
(a) make a long upward cut from 1 1/2 to 2 inches long, almost to the center of the stem.
(b) Insert a wood sliver, toothpick into the wound to hold it open and prevent cut tissue from reuniting.  Rooting compounds are unnecessary.





2. Apply a handful of damp sphagnum moss or well broken down compost so that it envelopes the wounded portion of the stem. Tying the organic material in place with string helps keep it in position. The organic material should be soaked thoroughly to insure that it is completely moist. Squeeze out surplus water, since excessive moisture which can result in decay and deterioration of the plant tissue.




3. Use a sheet of polyethylene (plastic) film large enough to cover and wrap the ball of organic material using the butchers fold (see insert) to secure a tight seal where the two ends of the sheet are joined.



4. Draw the upper end of the film snugly around stem making sure that none of the organic material is exposed. Fasten it securely with electrician’s tape. Repeat the procedure on the lower end, again making sure there is a snug fit. Moisture must not escape and excess moisture must not enter from watering or rain. Some gardeners cover everything with aluminimum foil.



5. After the new roots have penetrated the organic material and are visible on all sides, the rooted branch may be removed from the parent plant. The rooting time will vary with plant variety as well as the season in which it is performed.



6. Remove the newly rooted plant from the parent plant with a knife or pruning shears, making the cut just below the ball of organic material and roots. Carefully remove the polyethylene film. Without disturbing the roots or removing the organic material, plant in a container using a good potting mixture or plant in a well-prepared soil bed.



7.   Placing a plastic tent over the newly potted plant for 4 to 8 days until the root system is well established is helpful as it will aid in preventing excessive loss of moisture. Keep the plant under a light shade and avoid direct sunlight until the new root system is well developed.

Many plants are lost in the final stage of the process because the root system is not sufficiently developed to sustain the top of the new plant. By using the plastic tent or by keeping the new plant in a humid environment, it is possible to develop a good root system on rather large cuttings. Once the roots are well established, it is best to harden off the foliage by gradually exposing it to normal atmosphere. This can be done by cutting a few holes every few days in the plastic tent to reduce the humidity until it is similar to the external atmosphere.



  Search Library Topics      Search Newspaper Columns