The magnolia family (Magnoliaceae), to which the tulip tree (Liriodendron) belongs in addition to the various magnolias, is the oldest family of flowering plants on earth according to current knowledge. They already existed more than 100 million years ago and from them all today’s angiosperms have developed – all known deciduous shrubs, perennials and grasses. A distinguishing feature of magnolias, of which there are around 80 species worldwide, is the primitive flower structure with a cone-shaped pistil and a variable number of helically arranged petals that are not grown together – this shows their still very close relationship to the green leaves.
Today’s magnolia species have their distribution areas in East Asia as well as North and Central America. Archaeological finds have shown that the Central European forests before the Ice Ages were also home to stately magnolias. However, they have died out with the advance of glaciers and low temperatures on the European continent.
Appearance and growth
The American species usually grow stronger and can develop into large trees, while the East Asian species remain smaller and often flower before the leaves shoot. Since they are also somewhat harder frost harder than their American relatives, Asians such as the star magnolia (Magnolia stellata), the Kobushi magnolia (Magnolia kobus) and the lily-flowered magnolia (Magnolia liliiflora) have the greatest importance in European gardens. There are also two hybrid groups: the extremely popular tulip magnolia (Magnolia x soulangeana) and the Löbners magnolia (Magnolia x loebneri). In the USA, a large-scale breeding program has been running for several decades. The aim is to cross various Asian magnolias with the American yellow flowering cucumber magnolia (Magnolia acuminata var. aurea) to create a new generation of early flowering and hardy hybrid magnolias with yellow flowers. The first new varieties such as ‘Butterflies’ and ‘Yellow Bird’ have already proven themselves in our gardens.
Depending on the species and variety, the various magnolias grow broadly upright or very expansive and form light, loosely branched crowns. The star magnolia is one of the smallest representatives and thus one of the magnolia trees for small gardens, with a height of barely three metres. The highest cucumber magnolia (Magnolia acuminata) in our latitudes is 25 metres. The bark of magnolias is usually light grey to brown and on the annual shoots often covered with clearly visible, light lenticels. The foliage is deciduous and alternate in most species, and also evergreen in some, such as the frost-sensitive evergreen magnolia (Magnolia grandiflora). The leaves are predominantly quite large and inverted ovoid to broad-oval. Like the bark, they exude an intense, slightly pungent odor when grated. The star magnolia is the first species to show its flowers from mid-March, the latest being the summer magnolia (Magnolia sieboldii), which blooms in June. The flower colours vary depending on the species from white to yellow and pink to pinkish-red and the flower shapes from tulip to star-shaped. The fruits of the woody plants are reddish-brown, cucumber-like aggregate fruits with bean-like, mostly black-brown seeds. Magnolias have a sensitive root system and prefer humus- and nutrient-rich, very loose soil with as even a humidity as possible. If the drought persists, they quickly turn yellow and stop growing. The location should be as sunny as possible and somewhat protected because of the early flowering. The woody plants also grow in semi-shade, but the flower base is much smaller.
Magnolias are classic solitary shrubs for the spring garden and go very well with rhododendrons. Especially the expansive tulip magnolia is often planted in parks because of its impressive abundance of flowers. Give the crowns sufficient space so that they can spread undisturbed. Good bedding partners are all early bloomers, primarily bulb flowers such as daffodils (Galanthus), winter lentils (Eranthis), crocus (Crocus), pulmonary herbs (Pulmonaria) and fragrant violets (Viola odorata). Avoid competitive herbaceous perennials such as some ground-covering cranesbill species (Geranium). Star magnolia is also suitable for roof gardens if large plant containers are used and uniform irrigation can be ensured. Automatic drip irrigation is best.
Cover the root area after planting with bark humus and do not do any ground work so that the sensitive roots close to the surface are not disturbed in their development.
Magnolias don’t need a regular cut. It’s best to let them grow undisturbed. The tree-like representatives can be fasted up over the years in order to plant them underneath or to create a seat underneath.
Always plant magnolias in spring. Small, badly rooted plants can otherwise get into problems in the first winter. The flowers of the tulip magnolia are very frosty due to their early shoots. Here it has proved to be a good idea to mulch the root area thickly in winter during ground frost in order to delay the warming and thus the flowering period somewhat in spring.
For hobby gardeners the propagation of magnolias is only possible by lowering and sowing. However, both methods require a lot of patience: The countersinks have only formed enough roots after two years, the seeds sown immediately after harvest often germinate in the spring after next and then also very unevenly. The vegetative propagation of the garden forms in the tree nurseries also used to be carried out by lowering, but this is no longer economically viable due to the two-year rooting period and the time-consuming maintenance of the mother plant quarters. Most magnolia breeds today are propagated in greenhouses by cuttings, but this requires a high technical effort. The new magnolia breeds from the USA originate mainly from Meristemkultur, in order to be able to offer large numbers within fewer years.
Diseases and pests
Magnolias are largely resistant to plant diseases and pests. In rare cases bacterial leaf spots (Pseudomonas) may occur.
Magnolias in the our store-Shop