Cloning a plant means growing a new plant from an existing plant rather than by seed. Magnolias are commonly propagated this way. Indeed, propagation by air layering has been used by the Chinese for many centuries. When cloning a magnolia, patience is key since it takes one to two years to get a new tree.
Choose a stem about the thickness of a pencil on the plant you want to clone.
Strip about a 6-inch section of its leaves.
Beneath a node--a place where a leaf emerges--cut through the bark all the way around the stem. Make an identical cut about 1 ½ inches below the first.
Make a vertical cut to join the first two cuts. Remove the bark.
Scrape the exposed inner wood with the knife.
Soak a large clump of moss for at least an hour.
Brush the stem's exposed inner wood with root hormone.
Squeeze the excess water from the moss, then wrap it around the exposed inner wood, securing it with twine.
Wrap the film around the moss, sandwiching the ends together, then rolling them down as you would a lunch bag.
Gather the top of the film against the stem, then tape it closed around the stem. Do the same with the bottom opening. The moss should now be completely sealed.
Cover the film with foil.
When roots have worked their way through the moss on all sides, prune the branch off beneath the plastic to separate the new plant from the old. It will take 1 to 2 growing seasons for the roots to get to this stage.
Prepare a permanent home for the young tree by shoveling out topsoil to accommodate the root ball.
Mix the topsoil with an equal amount of coir or moss.
Remove the film.
Plant the tree. Fill the hole with the soil-coir mix.
Bend a low-growing stem until it touches the ground.
Dig out a 2- to 3-inch trench in the soil about 6 to 12 inches from the end of the stem. The trench should continue to the point where the stem first comes in contact with the ground.
Strip the leaves from where the stem first touches the ground to about 6 to 12 inches from the stem's end.
Cut a diagonal notch into the stripped portion of the stem, a bit below a node.
Brush rooting hormone into the cut.
Slide a toothpick into the notch to keep the cut open.
Put the stripped area of the stem into the trench, covering it with the soil-coir mix. Leave above-ground the 6- to 12-inch end of the stem, with leaves still attached.
Put a stone atop the soil, if necessary, to keep the stem beneath the ground.
Stake the 6- to 12-inch end of the stem so that it stands straight up.
Keep the area watered so it stays moist.
Cut the new plant from the old in early autumn or early spring after roots have formed, which will take one to two growing seasons.
Plant the new tree as you would for an air-layered plant.