At the recent Australian Associated Bonsai Clubs' annual Seminar, we had a
talk by Leo Coolwyn, who is a wholesale nurseryman with a great deal of
experience in growing and propagating conifers. One of the subjects he spoke
about was the latent incompatibility of the Japanese Black Pine and the
Japanese White Pine when it comes to grafting. The 5 needle White Pine is
commonly grafted onto the more vigorous 2 needle Black Pine and for a number
of years this appears to be working well, but it has been found that
eventually, the White Pine gradually deteriorates and dies. This may happen
as late as 15 to 20 years after the graft has taken. According to Mr
Coolwyn, pine grafting has to be specific, i.e. 5 needle pines onto 5 needle
pines, 2 needle onto 2 needle, and so on.
I asked on which pine the Japanese White could be grafted as there aren't
that many 5 needle pines to choose from, and whether in the end there was
any sense in grafting it at all. The answer was that, at the moment, that
was the big question, but the matter was being researched.

I am posting this because I wonder if more is known by specialised
horticulturists in N.America.

Additionally, I have two questions:
1) There have been many complaints about the difficulty of growing the
Japanese White Pine. Could the above have anything to do with it?

2) A lot of people swear by the importance of buying trees imported from
Japan. I have always wondered why. Do Japanese grafting methods differ from
those used in the West, by any chance? Are Japanese trees more viable?

With thanks in advance for more information on these matters,

Lisa