How can I propagate a Japanese umbrella pine?
Peter Thompson’s book, Creative Propagation (Timber Press, 2nd ed., 2005), states that Sciadopitys verticillata can be propagated by seed or by cuttings (the latter method in autumn, early winter, or early spring). Seeds will grow into the form inherited from the parent trees; cuttings vary. On page 153 of his book, Thompson says that the cuttings can be taken from almost any part of the plant, but he recommends using cuttings from the leader shoot in order to get a symmetrical tree with an upright leader.
There is information on propagation which comes from the USDA Forest Service National Seed Lab’s profile of Sciadopitys verticillata (no longer available online). Here is an excerpt:
“The seeds should be sown in the fall or stratified for sowing in the spring. Umbrella-pine is not easy to grow and is extremely slow-growing when propagated from seed (Halladin 1991). It has a tendency to form several leaders. Field planting has been done with 3+2 and 4+2 stock (Dallimore and Jackson 1967). Umbrella-pine can also be propagated by layers or by cuttings of half-ripened wood in summer (Bailey 1939). A nursery in Oregon propagates solely by cuttings because of faster results; Halladin (1991) describes the technique in detail.”