Hello. I read in Jim Gardiner's book that at least M. stellata and the deVos and Kosar hybrids can be kept in containers (Ron B also mentioned these in a recent thread), but that this requires 'considerable expertise', since the roots fear extremes of cold and heat. I am thinking of keeping a magnolia in a container outside. I have exprience with maples in containers, and know of the principles of container growing, but can anyone say more about the 'expertise' Gardiner is referring to? What special requirements are important to factor in? I also saw M. sieboldii subsp. sinensis mentioned, but may be this is too big a tree? Thanks for any hints. Schusch
Star magnolia and Kosar/DeVos hybrids subzero hardy, commonly and easily grown. Produced commercially in containers. If you are growing maples in pots with success similar approach to these should be fine.
Ron's note is really helpful. From my reading some years ago, I had the impression that growing a magnolia in a container was not going to work because magnolias need room for their sensitive roots - sensitive to rocking from wind, salt, and being disturbed by cultivation. Nevertheless, I have been growing a M. stellata 'Royal Star' in various sized pots for several years, and I must say that this spring the flower production was the best ever. It is over 4' high, and in a 24"w by 15"h pot, and does not get any more attention than the maples, and is fertilized only when the they are. Sunset's Western Garden Book (1995) treats magnolias in some detail. They rate various star magnolias as Sunset zones 1-9, 14-24, but warn of possible late frost injury, which is strange since in Idaho - Sunset zones 1-3, it can freeze in May. Kosar-DeVos hybrids are similarly rated at Sunset zones 2-9, 14-24. The following link may be useful for comparison with climate zones in Luxembourg. I recently acquired 'Galaxy' for my mom, but then thought that it might not make it in the wind of southern Idaho. Will it take a spot in the PNW with a fair amount of spring sun, but quite a bit more shade in summer? And is it a fairly slow grower; how tall will it be in 10 and 20 years?
Thanks Laurie. I only saw your reply now. Gardiner's book mentions that the Japanese grow M. stellata in containers. I note the sensitivity to the climate. Of course, one question is how long can one keep such a tree in a container before it gets adversely affected? To refer to bonsai, with very old trees in pots, might not entirely work, since these trees get looked after in a special way from early on, and we let these trees grow, with the occasional root pruning. When you say sensitive roots, you mean they do not like having their roost worked on repeatedly, like you would have when you plant them (getting rid of the soil that came with it), repotting and rootpruning? Can you say more about their roots needing room? Schusch