Everyone recognises the daffodil as being a major element of spring garden displays. Magnolias are just as important in the spring garden and make a fine show once established. A drive around any town or city in NZ will enable the keen observer to spot many different magnolias flowering from early spring to late spring.
One of the most important magnolias is Magnolia campbellii, but there are others equally important depending upon the effect gardeners are looking for. These include M kobus, M stellata, M x Soulangiana, M wilsonii and M seiboldii.
Magnolias belong to a large, varied genus of 125 species of deciduous and evergreen trees and shrubs from east Asia and the Americas was named after French botanist Pierre Magnol. The leaves are usually oval and smooth edged. Known for their elegant flowers and their distinctive character, magnolias are a showy group of shrubs and trees. The large spectacular flowers are generally large, fragrant and solitary with colours including white, yellow, pink or purple, and may be shaped like a funnel, cup, saucer or star.
Magnolias require deep, fertile, well-drained and aerated, mildly acid soil. The fleshy roots are fragile so the plants do not transplant readily. They thrive in sun or part shade but need protection from strong winds. The flower buds are frost sensitive. Branch structure and developing flower buds add interest in winter. Some magnolias flower when they are 2 or 3 years old and others take 10 or even 20 years to come into flower. They are well worth the wait.
This deciduous Himalayan species eventually grows 24 m tall with a 12 m wide crown in the right conditions and there are a few this size in NZ but usually they are a lot smaller. Its slightly fragrant flowers are up to 25cm in diameter and appear on leafless branches from late winter to mid-spring. Plants raised from seed may take from 6 - 20 years to flower. It is reliably hardy. Today there are some really good NZ raised cultivars and hybrids to choose from. ‘Alba’ has pure white flowers; ‘Charles Raffill’ is white and rose purple; ‘Lanarth’ is a deeper rose purple. Magnolia ‘Vulcan’ with dark red flowers.
Deciduous and conical, this Japanese species can reach 10 m tall although it is not often seen this big in cultivation. Its aromatic leaves are 20 cm long and mid-green in colour. The flowers are produced in early spring before the foliage and have long, narrow petals sometimes stained pink at the base. It can be seen planted as a street tree around Christchurch.
M. stellata (star magnolia)
This many-branched, compact, deciduous shrub from Japan grows 3 m tall and wide, with aromatic bark when young, and narrow dark green leaves. Fragrant, starlike, pure white flowers, 8 -12 cm wide, open from silky buds in late winter and early spring but its flowers are sometimes damaged by sudden frost. It flowers when quite young, and has several cultivars in shades of pink, including ‘Rosea’, ‘Waterlily’, the most prolific flowerer, has more petal and slightly larger white flowers. Though the shrub’s floral display is enchanting, its wonderful open form would recommend it even if it failed to bloom.
This deciduous hybrid between Magnolia denudata and M. liliiflora first appeared in Europe in the 1820s and is now represented by many cultivars. It is an erect tree 8 m tall and 4.5 m wide, usually single trunked. The dark green leaves are tapered at the base at rounded at the tip, with a short point. Blooms in goblet, cup and saucer shapes and in white, pink or deep purple-pink appear from late winter to mid-spring, before and after the leaves emerge. ‘Alexandrina’ flowers are pure white inside, flushed rose pink outside. Goblet-shaped cultivars include ‘Lennei’, beetroot purple outside, white to pale purple inside; ‘Lennei Alba’ with pure white flowers; and ‘Rustica Rubra’, rose red outside and pink and whit inside.
M wilsonii and M seiboldii
From China, these spreading, deciduous shrubs or small trees grow up to 6 m high and wide. In late spring and early summer fragrant cup-shaped yellow flowers with red or magenta stamens hang from arching branches among narrow dark green leaves that arc velvety be h. These smallish trees represents a group of deciduous summer flowering species from China, with pendent flowers distinguishing them from the upright ones of the better know spring-flowering species. The white blooms are beautifully fragrant.
Magnolia roots arc fleshy and fragile so transplant carefully in spring. Container-grown plants are the best. Look for well-branched plants. Plant them in a fairly shallow hole - just deep enough to cover the roots - but give them enough space for the roots to develop horizontally, and leave enough space for the free in its mature size.
Provide generous water until established, and then taper off to watering during dry spells. Most well-established shrubs growing in a good garden loam can easily tolerate a week or two without water. The frequency of watering and quantity of water will be determined by a number of factors, including soil characteristics and exposure. If the soil is not naturally rich, provide an annual application of organic mulch. Provide generous fertiliser until plants are established.
Some species of magnolia arc attacked by scale. If not controlled carefully, it can cover the plant. The tree is usually able to repel any diseases if properly sited and growing vigorously. Prune magnolias as specimen ornamental trees. To avoid water shoots, any summer pruning should be very light. Remove dead wood anytime.
Magnolias make such a fantastic display that all gardeners should find a home for at least one of the fabulous plants.