Magnolia

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. In recent decades these have been imported and planted here in Finland, where the Kobus magnolia is already known for its hardiness.

Loebner’s magnolia is a deciduous, erect small tree or large shrub, with slim branches. The crown, vase-shaped in the early years, becomes rounded in maturity. The star-shaped, scented flowers are 10-12 cms in diameter, with an average of 12 narrow white petals, though some forms have far more. Flowering occurs in early May, just before leaf-break.

The best known variety is probably ’Leonard Messel’, which probably had the pink-flowered rosea-form of the star magnolia as one of its parents. ‘Leonard Messel’ is probably the hardiest of the pink-flowered magnolias to have been tested in Finland. There are several other varieties and seedlings under test at Mustila, and time will tell how they develop, but the Loebner’s seems clearly more demanding than the Kobus, so far.

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).

The umbrella magnolia has probably the largest leaves of any tree that can be grown outdoors in Finland. They can grow to almost one metre, but about half that is perhaps more usual. The tree grows erect, but not very tall. Specimens of over ten metres are known in the wild but they are more commonly multi-stemmed and smaller, which is the form they seem to take in Finland.

The creamy white flowers are hand-sized and appear about the middle of summer at the ends of the branches, where they often go unnoticed among the large leaves. There are conflicting opinions on the pleasantness – or otherwise – of their scent.

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 species flowers in Finland after Midsummer when in full leaf, and can sometimes flower a second time in late summer. The blossoms are about 10 cm in diameter, usually drooping and not quite fully open so that to get a close look at detail they must be looked at from below. The Korean form (var. sieboldii) is most commonly grown, with attractive red stamens and a yellow pistil surrounded by white petals. The old shrubs of Alppiruusulaakso (Rhododendron Valley) and the western side of Etelärinne (Southern Slope) represent this form.

Siebold magnolia is considered the hardiest of the magnolias grown in Finland and in the right spot is hardy to Finnish zone III. However, there seems some variation in hardiness depending on provenance, and this species is among the most demanding of the genus with regard to the tenderness of its roots and foliage.