How to Root Lychee Cuttings
As mentioned, seed viability is scant, and traditional grafting budding techniques are unreliable, so the best way to grow lychee is via lychee cutting propagation or marcotting. Marcotting is just another term for air-layering, which encourages the formation of roots on a portion of a branch. The first step to growing lychee from cuttings is to soak a few handfuls of sphagnum moss for each layer for an hour in warm water. Choose a branch of the parent tree that is between ½ and ¾ inches (1-2 cm.) across. Try to find one that is located around the outside of the tree. Remove leaves and twigs from 4 inches (10 cm.) below and above the chosen area, within a foot (31 cm.) or so of the branch tip. Cut and peel off a ring of bark about 1 to 2 inches (2.5-5 cm.) wide and scrape the thin, white cambium layer off the exposed area. Dust a bit of rooting hormone onto the newly exposed wood and wrap a thick layer of damp moss around this section of the branch. Hold the moss in place with some twine wrapped around it. Wrap the moist moss with polyethylene film or plastic sheeting and secure it with ties, tape, or twine.
More on Propagating Lychee Cuttings
Check the rooting branch every few weeks to see if roots are growing. Usually, about six weeks after wounding the branch, it will have visible roots. At this juncture, cut the rooted branch from the parent just below the root mass. Prepare the transplant site in the ground or in a container with well-draining, slightly acidic soil. Remove the plastic film gently to avoid damage to the root mass. Leave the moss on the root mass and plant the new lychee. Water the new plant in well. If the tree is in a container, keep it in light shade until new shoots emerge and then gradually introduce it to more light.
