Propagation of Magnolia
Magnolia propagates by seeding and through vegetative propagation.
If we pick the fruit of magnolia in the middle of September and keep it in semi-darkness for some time, the seeds appear. The seeds do not germinate well because their surface is oily. So they must be rubbed with sand to remove the oiliness; then they should be dried in the shade for 4 or 5 days so that they contain some 20 per cent moisture. Then they should either be sown in fields from the end of September to the first part of October or vernalized and then sown in April of the following year.
Vernalization is done in such a way that immediately after the seeds are collected, they are mixed with wet sand and buried outdoors, or they can be stored for 180 days in cellars where the temperature is about 0-5 degrees C. and the moisture is some 75-80 per cent.
Should the vernalized seeds not sprout well, temperature of 22-24 degrees C. and adequate moisture should be provided for about 10 days to allow them to sprout fully prior to sowing.
Some 5-10 grammes of seeds per square metre should be sown either on ridges or hills by the method of hill seeding or drill seeding and they should be covered with earth to a depth of 2 or 3 centimetres. When the buds have grown to some extent they should be thinned out
A magnolia which has grown after seeding comes into bloom for the first time after 5 or 6 years
What is basic to the vegetative propagation of magnolia is the grafting.
In order to hasten the flowering period, grafting is done by using 2- or 3-year old seedlings as the stock and the branches of flowering trees as the scion. Either cleft grafting is conducted in spring or square bud grafting in June and July. Propagation is also done through layering, division .and cutting.
Based on: FLPH - Magnolia Sieboldii, Korea's National Flower