Tonight we had a short presentation by Amelia on air layering then anyone who wanted could have a chance to practice their air layering with the air layering kits Amelia provided.
Air layering stimulates the production of aerial roots which form in a moist environment as a response to the damage to the cells around the cut wound made on the stem from the upper section. Many species are suitable to take air layers from including Amelanchier, Apples, Azaleas, Beech, Birch, Blackthorn, Camellia, Chaenomeles, Cherries, Elms, Figs, Forsythia, Hazel, Jasmine, Juniper, Lilac, Magnolia, Maples, Oaks, Pears, Privet, Lime, Rhododendron, Spindle, Yew and Laburnum to name a few.
The tools needed to carry out an air layer include a Sharpe knife or scalpel, clear plastic and black plastic squares, cable ties or wire, and moist sphagnum moss. Instead of plastic, you can use plastic air pods for ease. Ensure your knife or scalpel is clean to avoid transfer of infection between plants.
Step 1: Remove the bark down to the corky layer scraping off all the cambium tissue around the stem
Step 2: Tightly pack a small amount of moist sphagnum moss around the entire exposed section of the stem and ensure the top section is covered as this is where the roots will develop from.
Step 3: Wrap the wounded stem packed in moss with clear plastic, sealing both ends with wire or cable ties but allowing water to drain from the bottom and the top end to be able to be opened up from time to time to water to keep the moss moist at all times. The clear plastic allows for you to check to see if roots are forming within the moss.
Step 4: Wrap the clear plastic with black plastic to provide dark and warm conditions for root development. Seal the ends with wire or a cable tie but again allow one end to be able to be opened periodically to check for roots and water the moss.
Step 5: Leave the wrapping in place for up to 6 months or more depending on the species as some will develop roots quicker than others. Open and check it occasionally for signs of rooting as well as to water to ensure that the moss remains moist at all times.
Step 6: When strong new roots are visible through the moss, cut the stem just below the rooted section and remove the clear and black plastic coverings and pot up.
Step 7: Pot up the rooted stem without disturbing the sphagnum moss and new roots into a suitable pot to grow on and allow the roots to fully form and harden off.