Lily magnolia

Family

Magnoliaceae

Habit

Shrub

Height

3 m

Spread

4 m

Growth

medium

Lifespan

50 years

First yield

after 3 years

Hardiness

zone 6–9

Shade tolerance

partial shade

Soil

Sand, Silt, Loam

Soil moisture

semi-dry – very moist

pH

5.6 – 7.6

Synonyms

M. obovata. non Thunb. M. purpurea. M. quinquepeta. (Buc-Holz.)Dandy. Lassonia quinquepeta.

Other uses: Beyond its ornamental value the purple magnolia matters above all as a parent species. Around 1820 the French breeder Étienne Soulange-Bodin crossed it with the yulan magnolia Magnolia denudata, producing the saucer magnolia Magnolia × soulangeana, today the most widely planted magnolia in Europe. In the 1950s the same species gave rise at the US National Arboretum to the "Little Girl" hybrids, with cultivars such as 'Susan', 'Ann' and 'Betty' that flower later and so dodge late frosts. Cut branches carrying fat flower buds open in a warm room and are forced as spring decoration. In Chinese temple gardens the species is a fixture.

Site: At 2.5 to 5 metres tall and 2 to 3 metres wide the purple magnolia stays a large shrub and therefore fits smaller gardens too. What matters most is protecting the bloom from frost: it opens from April, and a single late frost turns the flowers brown within hours. A position that the morning sun does not strike immediately and that does not collect cold air often buys the flowers several days. As a shallow-rooted shrub it threads the topsoil densely and tolerates neither digging nor competing underplanting; a permanent mulch ring beats a perennial bed. It needs acidic to neutral, humus-rich, free-draining soil, as calcareous ground causes chlorosis. Care: Water deeply in the first years and in every dry spell, since magnolia roots lie shallow and dry out fast; use low-lime water. Mulch with leaf litter or bark humus rather than hoeing, as every root injury takes its toll. Do not prune as a matter of course: magnolias seal wounds poorly and barely resprout from old wood, so remove only dead or broken branches, and do that in summer after flowering. Feed sparingly in spring with an acidic rhododendron fertiliser. Protect young plants against frost cracks in their first winter. Diseases are rare, with occasional leaf spot after wet springs.

The purple magnolia can be propagated several ways, none of them quick. Layering is the most reliable: a low one-year shoot is nicked in spring, pegged down shallowly and weighted; after one to two years it has its own roots and can be severed. Semi-ripe cuttings in June or July root under mist with rooting hormone, though erratically. In the trade, cultivars are grafted onto Magnolia kobus seedling rootstocks. Seed is possible but slow: the fleshy red aril must be rubbed off completely or nothing germinates, after which the seed needs several months of cold stratification. Seedlings do not flower for about ten years and do not come true to type.

The purple magnolia is a neophyte with no specialised associated fauna in central Europe; native species have not adapted to it, and caterpillar feeding is only occasional and unspecific. Its contribution lies in timing: it flowers from April to June and so offers food at a point when little else is open. Here it is visited by bumblebee queens, hoverflies and beetles. In evolutionary terms magnolias are beetle flowers: they arose before bees existed, and their strikingly tough, fleshy tepals are an adaptation to gnawing beetles as pollinators. As a nesting shrub and cover it matters little, given its open branching; anyone aiming to support fauna deliberately should add native early-flowering woody plants such as goat willow or cornelian cherry.

Notable: magnolias are older than bees → tough, fleshy tepals as armour against the gnawing beetles that originally pollinated them; genus named after the botanist Pierre Magnol (1638-1715); mother of the saucer magnolia that Soulange-Bodin raised from it around 1820; a temple and garden tree in China for centuries; threatened in the wild, surviving mainly in cultivation.

East Asia: China (Hubei, Hunan, Yunnan, Fujian, Sichuan). The purple magnolia comes from the humid subtropical mountain forests of south-central China, where it grows on slopes and woodland edges between roughly 300 and 1600 metres. Its wild population has shrunk severely through land use and is listed as vulnerable by the IUCN; the species now survives largely in cultivation. It has been planted as an ornamental and in temple gardens across East Asia for centuries. It reached England in 1790 and spread rapidly through Europe from there. It does not naturalise in central Europe; every stand here is planted.

The purple magnolia comes from the permanently humid subtropical mixed broadleaf forests of south-central China, where it grows on slopes, along streams and at woodland edges between roughly 300 and 1600 metres. The climate there is wet year-round with mild winters and humid, warm summers, without a pronounced dry season. It is not a plant of closed forest interior but of the half-open transitional zones where enough light reaches the shrub layer; the soil there is deep, humus-rich, free-draining and acidic. Its natural habitat has shrunk severely through land use, so the species counts as threatened in the wild and survives chiefly in cultivation.