Loebner’s magnolia is a cross between two Japanese species, the star magnolia (M. stellata) and the Kobus magnolia (M. kobus). These two species don’t occur together in the wild, so the first hybrid was therefore a garden one, a cross made by the German Max Löbner shortly before World War I. The first plants were put on sale in 1923, and five of them were purchased by Kordes, already known as a rose-breeder, from Germany’s Sparrieshoop. Later the hybrid has been grown from seed, with numerous varieties selected and named.
This North American magnolia gets one of its names from the way the large leaves form umbrella-shaped bunches at the ends of the shoots. It has become known in Finland as a result of Arboretum Mustila’s seed collecting expeditions. There are now a number of plants in the country which have passed the seedling stage and are young trees. Perhaps the best are those growing against the wall of Helsinki’s Vanha Kirkko (Old Church), despite the fact that they have been wrongly named cucumber trees (M. acuminata).
Siebold magnolia has grown well at Mustila and elsewhere in southern Finland when it has been planted in rich soil in semi-shade. Its native habitat is in eastern Asia, in particular among shrubbery on volcanic soils.
The Japanese whitebark magnolia is one of the most tropical-looking tree species which can be grown in Finland. It has the northernmost range of any of the magnolias, growing naturally as far north as the Kuriles and Sakhalin Island.
The Kobus magnolia has been an important tree to Japanese farmers throughout history. When the mountain magnolias turned into a sea of white flowers the farmers knew the time was ripe for spring sowing.
Kobus magnolia is found throughout the whole of Japan excepting the northernmost parts of Hokkaido. The species was first brought to Europe in the late 1770s and became very popular due to its winter hardiness and early, brilliant flowering.
This species was found in the wild at the end of the 1800s but didn’t reach the west until 1977. Plant hunter Ernest Wilson, whom we can thank for many of our finest garden plants, collected herbarium samples of Magnolia biondii in 1907, but the seed he collected never germinated. Perhaps they dried out on the long journey west, which is fatal to magnolia seeds.
This yellow-flowered and probably extremely hardy magnolia hybrid, the result of work by the American August Kehr, resembles many other yellow-flowered varieties which have become popular in North America. The yellow pigment of the flowers and the tree-like habit are inherited from the cucumber tree (M. acuminata). The foliage and flowering are more like those of its other parent, the white-flowered ‘Norman Gould’ variety, which is a Kobus magnolia whose chromosomes have been artificially doubled to make it tetraploid.
This cross between the Japanese bigleaf (also called whitebark) magnolia (M. obovata) and the Siebold magnolia (M. sieboldii) just bursts with tropical luxuriance, and is very promising in Finnish conditions. Older nursery stock may be rather tender but Gothenburg Botanic Garden has produced the varieties ’Aashild Kalleberg’ and ’Swede Made’ from apparently hardy parents, which may well prove hardy in southern Finland, too.
Seed collected from willow leaf magnolias (M. salicifolia) in collections produce hybrids with star magnolia (M. stellata), and vice versa. Such hybrids appear to be among the hardiest of the magnolias. Experience in Finland so far only covers a short period but is very promising. The oldest of the shrubs at Mustila has already achieved flowering age.
’Wada’s Memory’ was named in memory of the famous Japanese nurseryman, Koichiro Wada. It is fast-growing and flowers abundantly while still young. Washington University in Seattle received a batch of seedlings from Wada in March, 1940. As they grew they all looked like typical Kobus magnolias except one. It grew quickly to a considerable size and flowered young. It is assumed to be a spontaneous cross between two Japanese native species, the Kobus magnolia (M. kobus) and the willow leaf magnolia (M. salicifolia).