Magnolia

The flowers on these attractive trees are gorgeous in bud as well as when open, says Miranda Kimberley.

M. Soulangeana - image: Floramedia
M. Soulangeana - image: Floramedia

Magnolia paint colour may be the byword for bland when it comes to interior design but there is nothing remotely bland about the tree. Blooms range from the purest white through to ivory, yellow and pale pink down to the darkest pinky-purple flowers that are gorgeous in bud as well as when open.

There are around 120 species, the majority of which originate from East and South East Asia, with others from North, Central and South America as well as the West Indies. They are deciduous or evergreen and form small to large trees and shrubs. They are generally spring-flowering, with the flowers appearing before the leaves. But there are also some summer-flowering magnolias.

Of the evergreens, the best-known is M. grandiflora, a handsome tree with dark-green leaves that are glossy on the topside and have a rusty brown indumentum underneath. It produces highly fragrant, cup-shaped cream flowers in late summer and autumn. It does not cope well below -5°C and suffers in exposed sites, so is best given the shelter of a warm wall. Another good evergreen, perhaps a little more tender, is M. delavayi. This has some of the largest leaves on an outdoor-grown evergreen in the UK.

There are plenty of deciduous gems. Larger trees include M. campbellii and M. acuminata. Incredibly, fossilised specimens of this tree have been dated to 20 million years ago, illustrating just how old the genus is. It bears yellow flowers and is the parent for many of the modern yellow-flowered hybrids.

Many magnolias are small trees, reaching around 6m, but one hybrid that can become a medium sized tree is M. × brooklynensis, a cross between M. acuminata and M. liliiflora. Its flowers are an intriguing mix of colours derived from its parents. There are plenty of smaller trees or large shrubs, including the widely planted M. × soulangeana, which becomes spreading, as does M. sieboldii and M. wilsonii Award of Garden Merit (AGM). These latter two resemble each other, with their pure-white flowers with red stamen centres, but sieboldii and the popular subsp. sinensis have broader leaves and wider, more lemon-scented, nodding flowers.

The star magnolias are particularly popular, with their star-like flowers featuring many thin, floppy petals. These are ideal for the small garden. There are also several excellent varieties recommended for a location where space is limited. Some of the best include M. 'Star Wars' AGM, M. 'Heaven Scent' AGM, M. liliiflora 'Nigra' AGM and M. 'Susan' AGM.

Magnolias are ideally planted in deep, fertile, slightly acidic to neutral soil. But many are lime-tolerant, including delavayi, acuminata, kobus, × loebneri and wilsonii AGM. They are very tolerant of heavy clay soils and atmospheric pollution. Mulch regularly. Plant early-flowering kinds in a sheltered area to protect from spring frosts and cold winds. Many species prefer a site in partial shade.

The species magnolias are usually grown from seed and it can take many years before they first flower. M. salicifolia AGM is one exception. However, a vegetatively propagated specimen of a named clone can flower from a very young age.

Pruning is kept to a minimum because it leads to vigorous growth of water shoots. But it may be needed if a tree gets too big or when wall training is required. It can be done after flowering in July for deciduous types or spring for M. grandiflora.

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What the specialists say

? Karan Junker, owner,

Junker's Nursery, Somerset

"We have around 300 magnolias. They are classic spring-flowering trees. There is a lot more variety than some people realise. Even among the spring-flowering selections there are lots of options — all shades of whites, through pinks to dark purples, even toning towards red.

"If spring frost is a problem in a locality, then consider one of the yellows, which generally flower later in the season — from April even into May. More unexpectedly, we also have a lovely collection of summer-flowering magnolias to continue the interest right through the season.

"M. grandiflora is a popular evergreen to grow against a wall. Not everybody is aware that many of the modern selections will grow perfectly happily as a free-standing tree too. These more recently bred forms are usually hardier and will flower from a younger age than traditional varieties.

"The taxonomists have recently amalgamated a number of other closely related genera into magnolia. My concern with this from the gardener's perspective is that a great many of these species are not fully hardy in this country.

"A pot-bound magnolia will take a long time to get going once planted. We grow ours in open ground, where they produce a much more natural root system. They are root balled for planting and establish brilliantly."

What the specialists say

Karan Junker, owner, Junker’s Nursery, Somerset

"We have around 300 magnolias. They are classic spring-flowering trees. There is a lot more variety than some people realise. Even among the spring-flowering selections there are lots of options — all shades of whites, through pinks to dark purples, even toning towards red.

"If spring frost is a problem in a locality, then consider one of the yellows, which generally flower later in the season — from April even into May. More unexpectedly, we also have a lovely collection of summer-flowering magnolias to continue the interest right through the season.

"M. grandiflora is a popular evergreen to grow against a wall. Not everybody is aware that many of the modern selections will grow perfectly happily as a free-standing tree too. These more recently bred forms are usually hardier and will flower from a younger age than traditional varieties.

"The taxonomists have recently amalgamated a number of other closely related genera into magnolia. My concern with this from the gardener’s perspective is that a great many of these species are not fully hardy in this country.

"A pot-bound magnolia will take a long time to get going once planted. We grow ours in open ground, where they produce a much more natural root system. They are root balled for planting and establish brilliantly."


Stephen Read, owner, Reads Nursery, Suffolk

"Magnolia is a highly ornamental tree for the garden that is attractive to wildlife and can also provide cut flowers. Not everyone knows, but there are many ancient medicinal uses for the bark and flower buds.

"My favourite has to be M. ≈ wieseneri. It's a compact tree or multi-stemmed shrub with white flowers and dark-red stamens. The sweet, spicy scent is absolutely superb. M. Felix Jury is an excellent variety. It's another compact tree with very large open flowers, deep pink in colour.
M. Black Tulip is an upright tree with deep-burgundy, red-plum coloured flowers held upwards on slender stems. The texture is almost velvet."


In practice

Robert Player, proprietor, Garden Associates, London/Hertfordshire

"Before planting any magnolia you must appreciate its ultimate size and the backdrop to its flower colour. A pure-white magnolia backed by a white building is a poor combination, whereas a purple M. lilliflora 'Nigra' or a 'Susan' would give a far more dramatic effect.

"Also bear in mind they are long lived, I look after several grandiflora in a London garden absolutely full of vigour and vitality, and they were planted by JC Loudon in 1837.

"The deciduous types are almost the ultimate shrub, with attractive pale-grey bark, the most amazing furry buds, incredible mostly scented flowers — M. ≈ loebneri 'Leonard Messel', a purpley-pink stellata-like flower that can withstand heavy frost. Don't forget their seed heads, fantastic things of red and orange that stop you in your tracks.

"Keeping a magnolia happy is like keeping a husband happy — feed him well and don't try and move him. Their liking for fertile, ideally slightly acidic to neutral soil (so watch out for chlorosis on slightly yellowing leaves if the soil is a bit alkaline) can make some varieties quite vigorous, so although most will require no pruning to keep a good shape, don't be afraid to get the secateurs out after flowering to retain the shape and density that suits your position."


Species and varieties

M. grandiflora 'Exmouth' AGM (H3-4) is a wonderful variety of the imposing evergreen North American species. It flowers at a younger age than the straight species, producing large, bowl-shaped cream flowers with a heavy scent. Like its parent, it has large, handsome leaves. Give it some shelter, perhaps against a wall. Height: 15m. Spread: 10m.

M. 'Heaven Scent' AGM (H4) is valued for its fragrance and compact habit, which makes it ideal for planting in a small garden. It is a deciduous type with an upright habit when young that spreads as it matures. It bears goblet-shaped, fragrant blooms flushed with pale pink on the outside between April and June. Height and spread: 5-10m.

M. liliiflora 'Nigra' AGM (H4) is a compact tree with dark pinky-purple flowers borne freely from spring to summer. Height: up to 6m.

M. ≈ loebneri 'Leonard Messel' AGM (H4) is a small tree with masses of early-spring flowers, dark lilac-pink on the outside, paler on the inside. Flowers well, even on young plants. Does well in all types of soil, including chalk. Height: up to 6m.

M. sieboldii is a beautiful spreading large shrub or small tree with a long-lasting flowering period from May to August. The cup-shaped flowers are pure white and fragrant, with a red staminal centre. Can be confused with M. wilsonii. Produces spectacular crimson fruit clusters in autumn. Height and spread: 6m.

M. ≈ soulangeana is perhaps the most commonly grown magnolia. It becomes a small, multi-branched tree and produces magenta-stained, creamy flowers during April before the leaves. Height: up to 6m.

M. 'Star Wars' AGM (H4) is a campbellii ≈ liliiflora cross and a vigorous grower, producing large, rich-pink, goblet flowers in spring followed by attractive, large, thick leaves. Introduced from Blumhardt of New Zealand and won the AGM in 2002. Height: 3-7m.

M. stellata AGM (H4), or the star magnolia, is so named because of the many petalled, floppy white flowers borne in early spring. Slow-growing, it eventually becomes a rounded small tree or large shrub. Height: 6m.

M. stellata 'Royal Star' is a very popular variety because it produces masses of slightly fragrant, pure-white, double flowers in late spring. It generally flowers up to two weeks later than other M. stellata types, meaning the flowers are less likely to suffer damage in a late-spring frost. Becomes a medium sized, densely branching, rounded shrub. Height and spread: 2.5m.

M. 'Susan' AGM (H4) is another excellent variety for a small garden. Reaching just 6m, it produces lovely deep pink-purple flowers that are borne in early spring. They are tightly fluted in bud and once open the colour really stands out.

M. wilsonii AGM (H4) is a large, spreading deciduous shrub that produces beautiful cup-shaped, pure-white flowers with contrasting crimson stamens in early summer. It also has unusually narrow, pointed leaves. Give it a prominent position, ideally in light shade, where it can be enjoyed and admired. Height and spread: 6m.

Thank you to Floramedia, which supplied the images for this article from its photo library
www.floramedia-picture-library.com.


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