Flowering Trees

There’s no doubt that city gardens now dominate that thoughts of plant breeders and nurseries and nowhere is this more evident than in the recent trends in the development of trees. Where once trees were though of as the major feature in a landscape, and large size was regarded as an asset, now we find that although gardeners still like the idea of trees, most find their bulk offputting. Today’s popular trees are those that are both ‘manageable’ and attractive; trees like the various forms of Gleditsia triacanthos, small rowans (Sorbus spp.) and Japanese maple (Acer palmatum) cultivars.Country gardeners, however, with their generally larger gardens, still need trees that make an impact and fill space. Large trees also help to reduce the force of the wind and can be used a boundary. Many country gardens are therefore both sheltered and defined by boundaries of large trees. But as effective as such plantings are at protecting the garden, filling space and hiding unsightly out-buildings or waste areas, they tend to be rather monotonous — often just one or two tones of green. A garden surrounded by a large shelter belt of conifers can, as the trees become larger, become very cold and darkly shaded.The answer is to inject some colour, and adding flowering trees to your shelter is one of the easiest ways of doing it. Flowering trees can also be used to brighten up dark corners anywhere in the garden and they are of course beautiful in their own right, irrespective of where or how they are used in the garden.Planting stylesThere are hundreds of trees that combine bright or interesting flowers with excellent growth characteristics. Some of them, such as the flowering gums (Eucalyptus spp.) and lace bark (Hoheria populnea), are suitable for breaking up a monotonous shelter belt, others are better used where their growth form has room to develop and be better appreciated.Specimen planting is one way to emphasise the characteristics of a particular type of tree. The silk tree (Albizia julibrissin), for example, generally looks best when grown as an individual specimen where the full beauty of its branch structure and spreading growth habit may be appreciated.Other trees are better grown in groups. Eucalypts and acacias are particularly suited to group planting and can be used in paddocks to create small shelter blocks or woodlots. Although acacias are prone to wind damage, they are very good for shelter as they are palatable to stock. Also, they are leguminous and therefore nitrogen fixing, though this is of little consequence except in the immediate vicinity of the trees.Most leguminous trees, for example acacias and carob, can be used for supplementary fodder; either through allowing the stock to browse low branches or by trimming some of the foliage as required. Carob, of course, also offers the benefit of its highly nutritious pods.However, stock rotation is important. Don’t leave the stock among the trees for more than a week or so, especially if feed is short supply, or the trees may suffer from stock grazing on or stripping the bark through rubbing. Dividing up your paddocks so that each contains a small shelter wood should avoid any problems developing.Some flowering trees, particularly the eucalypts, are suitable for use as timber trees or for coppicing. You will lose much of the benefit of the flowers with timber trees as they will eventually grow too high for the flowers to be very visible. On the other hand the regular trimming of coppiced promotes rapid new low-level growth that will develop into flowering wood at relatively. It is worth considering the flowering potential of your coppice trees when selecting plants and planning your trimming.The ultimate use of flowering trees is in a natural sustainable woodland. If you have the room this can be the most satisfying form of gardening, allowing all manner of perennials and other plant to be grown under the trees. Also, there’s nothing to stop a woodland being used for stock shelter, coppicing or even selective felling.Such small woods serve a variety of purposes: timber production, shelter recreational or aesthetic value and for its value as a wildlife habitat. Managing woodlots to best achieve these multiple objectives requires careful planning and a thorough understanding of the methods available. It is usually wise to consult forestry professionals.PlanningIntegrating flowering trees in your existing garden, shelter belts, woodlots can be viewed as landscaping on a grand scale. Getting the right combination of beauty, diversity and utility requires that the same considerations be borne in mind: size, colour, arrangement, texture, and form.Trees are, of course, large plants and seldom moved once established. This demands that you plan ahead to avoid any embarrassment as they grow. Just because you may have a large garden it doesn’t mean that you can’t run into problems with trees outgrowing their allotted space. Remember to consider the spread as well as the height: some trees, like the silk tree (Albizia julibrissin), may be wider than they are high, which is great if you need a shade tree for a lawn but is less appealing where fences and hedges set limits for the spread of the tree. Consider the roots too: it’s no fun having to dig up your sewers or clean out drains blocked or crushed by tree roots.Equally important, any plant you choose must be able to survive in your climate and soil. Frost and wind tolerance and rainfall are the main climatic concerns, while drainage, depth, humus content, and pH are the most important soil considerations. The climate will also determine the rate of growth. Some trees are naturally fast growers, and the more suitable the climate the quicker the tree will grow.The aspect and the angle of the sun, which varies with the seasons, determine how much shade a tree will cast. Any large tree will provide shade throughout the year, but when the sun is at its lowest in winter, a wide-spreading tree can shade a considerable area. Dense, heavily foliaged evergreen trees provide the best privacy but have little else in their favour; they cast too much shade and it’s very difficult to grow other plants under them.A good selection of trees will provide year-round colour and interest. It may be difficult to find many trees that bloom in winter in inland or southern areas with cold winters and regular heavy frosts, but in most parts of the country it is possible to have at least one or two trees in bloom at any time. Cherries, crab-apples, dogwoods and the like are the traditional spring-flowering trees; they are followed in summer by the brighter-flowered eucalypts, pohutukawa (Metrosideros excelsa) and sub-tropicals such as Jacaranda; Autumn sees the cassias (Cassia and Senna spp.), Hoheria, kamahi (Weinmannia racemosa) and more eucalypts; while winter is the time for the witch hazel family, and, as the season turns to spring, the acacias begin to bloom.If your winter climate is too cold for much in the way of bloom, consider the beauty of coloured bark. The vivid red twigs of the dogwood (Cornus stolonifera); the stark white stems of the ghost gum (Eucalyptus pauciflora) and the silver birch (Betula pendula); or the rich reddish-brown, peeling bark of the paperbark maple (Acer griseum) or the Arbutus species.Foliage is important too. Given the choice, most gardeners will opt for evergreens over deciduous plants — the advantage of year round foliage is nearly always decisive. However, deciduous trees have plenty to offer, not just in terms of their superiority as shade and compost providers, but as ornamental plants too. Think of deciduous trees and the first thing that comes to mind is autumn foliage, those vivid tones of yellow, orange and red, but the bright green of the new spring growth should not be underestimated. There is also a wide range of summer foliage colour among the deciduous trees, the bright yellow of Robinia ‘Frisia’, the deep blackish red of the copper beeches (Fagus) and the silvery grey of the weeping silver pear (Pyrus salicifolia).So, what are the best flowering trees? Well, that really depends on your climate and personal preferences, but the following selection covers most of the proven performers.AcaciaThe over 500 species of wattle, most of which are native to Australia, are predominantly evergreen, quick-growing, heavy-flowering, generally hardy and range in size from small bushes to large trees. Most have golden-yellow flowers, are relatively short-lived and tend to have rather brittle branches that are easily damaged by wind. This brittleness makes most wattles unsuitable for shelter plantings, although the sallow wattle (A. floribunda) is often used as a quick screen. A light, sandy or gravelly soil will slow the growth rate and lead to stronger branches.Despite the enormous choice, relatively few are commonly grown. By far the most common is the Cootamundra wattle (A. baileyana), which has fine, feathery foliage, grows to about 8 m high × 10 m wide, and produces massed clusters of flowers in late winter and spring. The alpine wattle (A. pravissima) is smaller (around 5 m × 6 m) and has bright yellow flowers. It has triangular, pointed phyllodes (leaflets) and is hardy over most of the country. Acacia cardiophylla has ferny foliage, strongly cinnamon-scented pale yellow flowers in winter and spring, and grows to about 12 m × 8 m.In common with other legumes, wattles have the ability to store atmospheric nitrogen in nodules on their roots. They also have edible foliage and flowers. Their sap is used as a gelling and thickening agent in foods, particularly ice-cream.AlbiziaBecause of its flat-topped, spreading habit, the common deciduous silk tree (A. julibrissin) is usually grown as a shade or lawn tree. It has large fern-like (bipinnate) leaves composed of many tiny leaflets. In summer it produces fluffy, ball-shaped, filamentous, pale yellow and pink flowers. The form ‘Rosea’ has deep pink flowers. The silk tree grows to about 6 m × 8 m and thrives in light well-drained soil. It is inclined to be shallow rooted and benefits from staking when young.A. lophantha is a somewhat frost-tender evergreen species that closely resembles an acacia. It has bright, slightly glaucous, green pinnate leaves and 100 mm-long fluffy yellow bottle brush flowers. It grows rapidly to 7m × 4m and can become invasive as it self-sows freely.AshAsh (Fraxinus spp.) is a Northern Hemisphere genus. The common F. excelsior is a 15 m high × 9 m wide, broad-headed, deciduous tree that is frequently used as a street tree. It has 200 mm-long pinnate leaves usually made up of seven leaflets and bears panicles of tiny, fragrant, white flowers in spring. Although this species does not flower as well as some of the others, several forms, the most common of which is the claret ash, ‘Raywoodii’, have been selected for their autumn foliage colour.The desert ash (F. oxycarpa) is similar but has slightly smaller leaves. It is flower very heavily in spring and is tolerant of drought and a wide range of soil conditions.The third common species is the manna ash (F. ornus). This species has a dense foliage cover and large flower heads. It colours well in the autumn. F. mariesii is similar to F. ornus in shape and leaf, and is probably the best flowering species.Ashes are among the last trees to come into leaf in spring, which makes them effective paddock trees as the spring grass growth can get underway without excessive shading. They can be used as fodder trees but do always regenerate quickly.Cabbage treeThe native cabbage tree (C. australis) is extremely well known for its distinctive foliage and growth habit, but less well known for its beautiful, large panicles of fragrant, creamy-white flowers. These appear in spring and are followed by small white berries. Several selected foliage forms, including the beautiful variegated ‘Albertii’, are available.The mountain cabbage tree (C. indivisa) has much wider, somewhat glaucous, leaves with prominent ribbing. It is an attractive plant but demands moist soil and high humidity to be at its best. Cabbage trees prefer moist soil and are quite tolerant of poor drainage. They can be used as living pumps to aid drainage in wet areas.CarobThe carob tree (Ceratonia siliqua) is evergreen and has 300 mm-long, leathery, pinnate leaves. It grows to about 15 m high and is strongly built, with a particularly stout trunk. Carob has very strong roots that can lift paving, so take care not to plant it near paths and driveways. It is very drought tolerant once established.The mid to late spring panicles of red flowers are followed by 150–300 mm-long seed pods that are filled with seeds surrounded by a sweet edible pulp. The pods make a very nutritious stock feed, but the tree requires a hot, dry climate to grow well and set seed.CassiaMany of the species in this large genus have been reclassified as Senna, but they are likely to be known as Cassia for many years. The most common species is C. corymbosa, particularly the form ‘John Ball’. It grows to about 4 m × 4 m and has bright green pinnate leaves that are up to 150mm-long and composed of leaflets with prominent midribs. It produces yellow, buttercup-like flowers in large clusters appear from about the middle of March. Grow in light well-drained soil in full sun and protect from frost when young. Most other species have a similar appearance but vary slightly in size, leaf shape and flowering season. C. tomentosa is a shrubby winter-flowering species that may self-sow and become invasive.Cassias are legumes and can fix atmospheric nitrogen, which enables the plants to grow on relatively poor soils. The seeds often have a laxative effect (one species is the source of senna), though how this affects stock is not clear.CatalpaThe Indian bean (C. bignonioides) is a large (20 m × 15 m), deciduous North American tree. It had large, light green oval leaves and in summer produces upright clusters of cream to very pale pink, tubular flowers. It is often said that this is one of the few very hardy trees with flowers that can rival the flamboyance of the tropical trees. This may be stretching things a bit, but there’s no denying that a mature catalpa in full bloom is an impressive sight. The Indian bean is easily grown and the only real complications are those that may result from its large size.I was unable to confirm that the large, succulent foliage is edible, but as the plant belongs to the bignonia family it is unlikely to be poisonous.CercisJudas tree (C. siliquastrum) and Chinese redbud (C. chinensis) both grow to about 8 m × 5 m, have distinctive light bronze-green, heart-shaped leaves and springtime flower clusters in an unusual shade of purplish pink. The flowers are followed by bean-like seed pods. White flowered forms are available. The foliage often colours well in the autumn. These trees are nitrogen-fixing, drought-tolerant once established and easily grown in any reasonably well-drained soil.Crab-apple and hawthornsCrab-apples (Malus spp.) used to be among the most widely planted flowering trees before they were tainted with a reputation for spreading the fungal disease fireblight. Although this discrimination has been shown to be somewhat unfair, the damage has been done.Hawthorns (Crataegus spp.), which are closely related to crab-apples, have suffered from the same problem. They too are superb flowering trees and really do merit a revival in popularity.Both crab-apples and hawthorns are very hardy. Most species are deciduous, though a few, notable the Mexican hawthorn (C. pubescens), are evergreen. They produce apple-blossom-like flowers in spring, which may, depending on the cultivar, be single or double, in various shades of white, pink and red. The flowers are followed by conspicuous fruit that is usually red or golden yellow. The fruit is edible but very tart, it can be used for making jams or jellies.Popular cultivars include the heavy flowering M. floribunda; M. ‘Oporto’, which has very deep plum-coloured flowers; M. ‘Jack Humm’, which is primarily grown for its bright red fruit; and C. laevigata (syn. oxyacantha), particularly the white-centred, red-flowered ‘Puniceus’ and the double forms.Crepe myrtleThe crepe myrtle (Lagerstroemia indica) is a beautiful heavy-flowering small (6 m × 4 m) tree that needs consistent summer heat to flower well. Although deciduous it is not particularly hardy, being damaged at about -6°C. The simple glossy deep green oval leaves are about 60 mm long and are usually carried in groups of three. In summer the tree produces clusters of 30 mm diameter frilly flowers. There are many colour forms in shades of white, cream, pink, mauve and red; there are also dwarf forms suitable for tub cultivation. Grow in well-drained soil in full sun and water well in summer.DogwoodDogwoods (Cornus spp.) are among the most beautiful small deciduous flowering trees. Dogwoods have simple but bold spring flowers, good autumn foliage colour, and some have brightly coloured winter stems. C. controversa, C. florida and C. kousa usually have the best flowers, while C. nuttalii provides brilliant autumn colour. C. alternifolia has a graceful tiered growth habit, but insignificant flowers. C. stolonifera has bright red winter twigs and C. capitata is evergreen with unusual fruit.Most species have pointed oval leaves about 125mm-long and there are some attractive variegated forms. The flowers have four leathery petals and are usually white when first open but develop pink tints as they age. The flowers are often followed by large round fruits that are seen at their best on C. kousa and the evergreen C. capitata.Most dogwoods are very hardy but C. capitata is often damaged at -6°C when young. They do best when planted in moist, humus enriched, well-drained soil in sun or light shade. Dogwoods are great for use around the edges of a woodland; providing interest through most of the year and adding a graceful light touch in spring.Eucalyptus, Agonis and MelaleucaThese three genera from the myrtle family are almost exclusively Australian plants. They thrive in any well-drained soils but vary in their frost-hardiness.We all know the typical eucalypt or gum tree with its peeling bark and sickle shaped glaucous green leathery leaves. All produce filamentous flowers in shades of white, cream, pink, yellow, orange or red, varying in size and season. Some, such as scarlet-flowering gum (E. ficifolia), put on a truly magnificent floral display while others, such as E. nicholi, have insignificant flowers.Eucalypts range in size from the snow gum, E. pauciflora var. niphophila, at around 6 m high to giants, such as E. globulus, which may exceed 60 m. Gums vary in their hardiness: some are almost totally intolerant of frost while others can withstand -15°C.Many gardeners reject eucalypts because of their rapid growth, leaf and bark litter, and potentially large size. However, they are among the most attractive and easy care evergreen trees available. And of course they really shine as quick-growing farm trees; a range of species can provide plants suitable for timber, coppicing and flowers, which are particularly popular with bees. Some, such as E. sideroxylon, are multi-purpose trees.Although Agonis flexuosa could easily be mistaken for a eucalypt when not in flower, its clusters of star-shaped creamy-white flowers, which appear in summer, give it away. This 8–10 m high tree is usually upright and quite narrow with weeping branches. It is easily grown but will not tolerate heavy frosts.Melaleuca or paperbark is a genus of about 140 species of evergreen shrubs and trees. Most have tiny needle-like or elliptical leaves. The flowers are similar to those of the closely related bottlebrush (Callistemon sp.) but are usually smaller. There are species in almost every colour of flower, though cream, yellow, pinkish mauve and red predominate. Paperbarks will grow in a wide range of soils but few are hardy below -6°C.EucryphiaWhile not widely grown, this genus includes several attractive large shrubs or small trees native to Chile and Australia. The most common species is E. cordifolia, a Chilean native. The other Chilean species, E. glutinosa, is rarely seen in gardens but has been crossed with E. cordifolia to produce the hybrid E. × nymansensis. The three Australian species, E. milliganii, E. moorei and E. lucida are rarely seen. All have similar anemone-like white flowers that appear in spring.Golden-rain tree style='font-family: "Times New Roman";font-weight:normal'>The golden-rain tree (Koelreuteria paniculata) grows to about 10 m × 7 m and has pinnate leaves that may be as much as 50 cm long. The foliage tend to be among the last to fall in autumn and often turns a bright yellow before dropping. In summer it produces large terminal heads of yellow flowers that are followed by clusters of papery seed capsules. It will grow in most soils and can withstand high alkalinity, as well as being very heat and drought tolerant once established.GrevilleaThere are at least two species of this proteaceous genus that develop into trees. Both G. banksii and the silky oak (G. robusta) have bronze green pinnate foliage and develop into round-headed trees. Though similar in appearance, G. robusta is considerably taller than G. banksii: 15 m high as opposed to 6 m. Both flower in late spring to mid summer. G. banksii has red flowers while those of G. robusta are golden orange. These trees prefer a well drained, somewhat acid soil and are frost tender when young. When mature they will tolerate at least -5°C.Several other protea family genera, most notably Banksia, Embothrium, Macadamia and Telopea, include tree-sized species. The New Zealand honeysuckle or rewarewa (Knightia excelsa) is also in the protea family. Its brownish-red flowers, while interesting and unusual, are scarcely spectacular. Bellbirds and other nectar-feeders find all of these flowers attractive.HoheriaTrees of this New Zealand genus are commonly known as ribbonwoods or lacebarks because of the fine filigree of bark that underlies the surface bark. The most common species is the evergreen H. populnea. When young it is a very upright tree, but as it ages it becomes more round-headed and grows to about 12 m high. Various foliage forms are available, though all produce massed small clusters of 2 cm diameter white flowers in late summer and early autumn. Other evergreen species grown include H. sexstylosa, which is very similar to H. populnea, and H. angustifolia.The two deciduous species, H. lyalli and H. glabrata, are similar to one another. H. lyalli grows to about 7 m while H. glabrata is a little taller at 9 m. The leaves are similar to H. populnea but covered in fine hairs. H. glabrata has somewhat bluish leaves. Both species flower in summer and are hardy to at least -15°C. Grow in moist, humus enriched, well-drained soil in sun or light shade.JacarandaJacaranda mimosifolia is common in milder areas and is sometimes used as a street tree. It is a semi-evergreen or deciduous 12 m × 8 m tree that is almost totally frost-tender when young, but tolerates -5°C once well established. Although the very finely divided fern-like leaves are attractive, jacaranda is mainly grown for its spectacular clusters of bright purplish-blue trumpet flowers. These may appear in spring in very mild areas, with summer the main flowering season. White and pink flowered forms are occasionally available. This tree needs warm temperatures to flower well and does best in moist well-drained soil in full sun.KamahiKamahi (Weinmannia racemosa) is a very attractive native evergreen. Up to 15 m high when mature, though shrubby for many years, it has elliptical, deep bronze-green, serrated-edged leaves up to 100 mm-long. In summer, the tree produces masses of 150 mm-long, narrow creamy-white bottlebrush-like flower heads. The massed flowers often swarm with bees as they are heavy with nectar and pollen. The flowers are followed by 20 mm diameter red berry-like fruits. There is also a purple-leafed form. Kamahi prefers a moist, slightly acid soil and is easily grown in most parts of New Zealand. The towai (W. silvicola) is a similar species that occurs in the north of the North Island, although it appears to be hardy well outside its natural range.KowhaiSo well known as to scarcely need describing, the two common tree-sized kowhai species (Sophora tetraptera and S. microphylla) are hardy, heavy-flowering and easily grown. These species are evergreen for most of the year but often drop most of their leaves as flowering begins in late winter or early spring. S. tetraptera has large olive-green leaflets that can be quite stiff and leathery, which tends to make the leaves curl slightly. It has pendulous clusters of large bright yellow flowers. S. microphylla has very small deep green leaflets and flowers that are smaller than those of S. tetraptera, but there are more blooms per cluster and they tend to be a golden, rather than bright, yellow. The flowers of both species are followed by brown, bean-like seed pods. Kowhai is best grown in moist well-drained soil in full sun.Several exotic species are also grown. Of these, S. japonica is the most common. It has deciduous, 200 mm-long, light green, pinnate leaves and cream, or occasionally pale pink, flowers in 200–300 mm-long terminal panicles. It may grow to 15 m × 12 m but is often grafted onto 2 m standards to produce a small weeping tree. It is hardy to at least -25°C.LagunariaThe Queensland hibiscus (L. patersonii) is a small evergreen tree. Quick-growing when young, it slows considerably after reaching 4 m. It has mid green leathery oval leaves about 75 mm-long with silvery grey undersides. The 40–50 mm diameter mid pink mallow-like flowers are followed by seed pods that contain irritant hairs. Remove the pods before they ripen unless you want to collect the seed. Queensland hibiscus is frost tender but otherwise easily grown in most well-drained soils and is a good coastal tree.LaurelThe bay laurel (Laurus nobilis) while doing double duty as a classic culinary herb and a first rate garden specimen is seldom grown for its flowers. The Canary Island laurel (L. azorica), however, offers equally attractive evergreen, deep green, oval foliage with the added bonus of large clusters of cream flowers in late spring. It is a hardy and easily grown tree that can mature to 15 m high or more.Lily-of-the-valley treeThe lily of the valley tree (C. arborea) is an evergreen large shrub or small tree — advanced specimens may reach 6 m × 3 m. It has large, deep green, laurel-like foliage and from mid summer bears masses of mildly fragrant, white, lily-of-the-valley flowers in large panicles. It is not entirely hardy but will withstand occasional frosts of -6°C. Clethra does best in cool, moist, humus enriched soil in sun or light shade.MagnoliaMost species of magnolia can eventually reach tree-like size, but those most commonly grown as trees are the deciduous M. campbellii and the evergreen M. grandiflora.M. campbellii, which may grow to 20 m × 12 m, has long, mid green, oval leaves, very like those of the common M. soulangiana. It is also one of the earliest to flower: usually starting to produce its vase-shaped cream to deep pink blooms in mid August. M. grandiflora grows to a similar size and has leaves that are a glossy mid olive green on top with rust coloured felting below. Some forms, such as ‘Ferruginea’, have very heavy felting. The flowers, which are fragrant, are creamy-white and cup-shaped. In some forms they can be up to 250 mm in diameter.Plant magnolias in moist, humus enriched well-drained soil in sun or very light shade.PaulowniaThis is a Chinese genus of about half a dozen very quick-growing deciduous trees, some of which have recently been promoted as timber trees. P. tomentosa is the species generally grown as a garden specimen. It is a hardy, strongly branched tree with large (up to 300 mm-long), heart-shaped leaves, deep green on the upper surfaces and light green underneath with some felting. It grows to about 15 m high × 8 m wide. The spectacular purplish-blue trumpet flowers are carried in foxglove-like heads and open in spring from the terminal heads of furry brown buds that are carried right through winter. They are followed by rounded seed capsules that hang on well into winter. Trees often carry the current year’s seed capsules and the following season’s buds at the same time. Paulownia grows satisfactorily in most well-drained soils.PrunusThe showy flowering Prunus — cherries, apricots, plums, peaches and almonds — are among the most common ornamental deciduous trees. Several species and many hybrids are grown and they range in size from the very dwarf almonds, such as the P. glandulosa forms, which are suitable for small gardens and containers, through to large spreading trees, such as P. sargentii, which may grow to 18 m × 12 m.Always heavy flowering, they vary in colour, size, style and season and growth habit. Among the most popular are the weeping and horizontal standards. These are naturally low, spreading plants that have been grafted onto upright standards from 1–2.5 m high. The standard trunk doesn’t grow any higher than the point at which it is grafted but the branches arch up and spread out to make a substantial plant.Flower colours are mainly white and various shades of pink. There are also a few very deep pink, bordering on red, cultivars and some with orange tints. Flowers may be single, semi-double or fully double. Often a double-flowered form will also carry some single flowers. Many of the ornamental forms are sterile and do not bear fruit, but some develop small, usually inedible, fruit after flowering. The trees are generally very frost hardy, although some of the very early flowering forms, such as P. subhirtella ‘Autumnalis’ or ‘Geisha’, may suffer flower or bud damage from hard frosts. Plant in moist well-drained soil.Pohutukawa and rataFrom mid November the pohutukawa (Metrosideros excelsa) becomes a very conspicuous feature of our coastal gardens as its clusters of intense deep red filamentous flowers begin to open. The simple rounded leaves are a bright glossy mid green on young plants but mature trees have deep green leathery leaves with white indumentum. Old trees often develop aerial roots on the trunk and branches. Various flower colours and leaf forms are available. Except for being frost tender, especially when young, this is an easily grown tree. It tolerates most soils and is particularly well suited to coastal conditions.The southern rata (M. umbellata) and the northern rata (M. robusta) are far tougher plants but they seldom do well in gardens. Their flowers are similar to those of the pohutukawa, but while spectacular in the wild, they are less showy in a garden. Both species are hardy to at least -10°C so they are worth trying in areas too cold to grow M. excelsa. They grow very slowly and may take many years to flower from seed.All Metrosideros flowers are nectar-rich and very popular with bees, birds and geckos.PuririThe puriri (Vitex lucens) is one of the few native trees with pink flowers. Most often seen in late winter, the panicles of bloom may occur at any time. They are followed by bright red 20 mm-long berries. The foliage of the puriri is very handsome: the leaves are a lustrous, glossy green; and composed of 3–5 broad leathery leaflets that are up to 125 mm long. Puriri grows to 15 m × 10 m and is a very impressive tree in all respects. Fittingly, it is host to one of our most impressive insects: the puriri moth. The caterpillars of this large moth can often be found on trees in the wild, but they usually do little damage. Puriri does best in a humus-enriched, moist well-drained soil and should be shaded and protected from wind and frost when young.Puriri wood is one of the most durable native timbers. It has been used for piles, fencing, bridges and other construction, while also being suitable for fine furniture. However, its slow growth rules it out as a commercial proposition.RobiniaThe golden-leaved R. pseudoacacia ‘Frisia’ is the most commonly planted member of this genus and has become enormously popular over the last ten years. However, it seldom, if ever, flowers. The true species, R. pseudoacacia, on the other hand, produces attractive, fragrant, white flower clusters in late spring and early summer. It can grow up to 25 m high and may be used as a fodder tree for stock capable of dealing with the vicious thorns on the stems.A selected form of another species, R. hispida, has recently been promoted as the pink wisteria tree. It has long racemes of pink flowers and grows to about 4 m. Robinias are easily grown in well-drained soil but have brittle branches that are easily wind damaged, so stake them well when young.RowanThe bright orange berries of the 8 m tall mountain ash or rowan (Sorbus aucuparia) are a common sight in autumn. Though usually grown for its berries, the cream spring flowers, while often rather unpleasantly scented, are nevertheless conspicuous. The colour of the berries varies with the species. Mountain ash has orange berries, S. americana has white berries, while those of S. hupehensis are white tinted pink. The smaller growing (up to 4 m × 1.8 m) S. vilmorinii is available in pink, yellow or red berried forms. Birds are attracted to the yellow, red or orange berries, but tend to leave the white berries. Some species, most notably S. discolor, have attractive autumn foliage but most show little autumn colouration. Rowans are easily grow in any well-drained soil and are most at home in areas with distinct winters.Strawberry treeThe strawberry tree (Arbutus unedo) is so called because of its prominent warty red fruit (attractive to birds) that follow the spring and summer clusters of lily-of-the-valley-like flowers. It is a hardy evergreen with rounded, dark green red-stemmed leaves, about 60 mm-long and finely serrated. The reddish-brown bark is attractive too, especially when wet. It is tolerant of coastal conditions and alkaline soil, which is unusual for an a member of the erica family. Grow in moist, well drained, humus enriched soil in sun or light shade. Although A. unedo is by far the most common species, I prefer A. canariensis as a flowering specimen.StyraxThese small deciduous trees have a neat growth habit and an attractive spring flower display. The most common species, S. japonica, grows to about 7 m and has deep green pointed heart shaped leaves and slightly drooping racemes of small bell-shaped white flowers. S. obassia is a slightly taller species that has fragrant flowers. Both prefer cool, moist, well-drained soil and cool, moist summer conditions. They blend well with rhododendrons, camellias and fuchsias.TamarixTamarisks can be untidy rangy growers, but are among the best flowering trees for coastal conditions. They have tiny adpressed leaves that are reminiscent of heather (Calluna). T. parviflora is usually regarded as the best flowering species and produces masses of minute, bright pink flowers in spring and summer. It grows to about 6 m × 3 m. Tamarisks prefer light well-drained soil in full sun. They are able to tolerate the full blast of coastal salt winds but are neater and heavier flowering if cared for with regular water and occasional trimming.Vanilla treeThe vanilla tree (A. microphylla) is a rather open growing tree (around 8 m × 5 m) with tiny rounded deep bronze green leaves and springtime clusters of small fluffy yellow flowers that are strongly vanilla scented. It is easily grown in most well-drained soils. A very attractive golden-cream variegated form exists but is only rarely available. A. lanceolata is a similarly sized species with larger leaves and larger but less scented flower clusters.VirgiliaAlthough they provide a good flower display, care should be taken when planting these evergreen South African natives. In many areas they self sow freely and may become weeds. Some authorities consider the two species, V. capensis and V. divaricata, to be variations of the same species. Both have deep green, somewhat leathery, pinnate leaves composed of many small leaflets. The underside of the leaves is light green to slightly silvery. From spring to early summer, pendulous clusters of pink to mauve sweet pea-like flowers appear. A tree in full flower is quite spectacular but the display doesn’t last long. Virgilias are easily grown in any light well-drained soil. They are best used as quick-growing temporary plants, as trees over fifteen years old often become very untidy and open.Witch hazelThe witch hazels (Hamamelis spp.) are hardy deciduous shrubs and small trees valued for the fragrant winter flowers, which have narrow, strap like petals and are best described as spidery. The most popular species, H. mollis, has spicily scented bright yellow flowers from mid winter. It may grow to 5 m × 3 m but is usually much smaller. H × intermedia, which is believed to be a H. mollis × H. japonica cross, includes several excellent forms, such as the brownish-orange-flowered ‘Jelena’ and the large-flowered ‘Arnold Promise’. All of the species and hybrids are hardy to at least -20°C although the flowers may be damaged by very severe frosts. Grow in moist, humus-enriched, well-drained soil in sun or light shade.The Persian ironwood (Parrotia persica) is a closely related plant that has reddish-orange flowers in late winter. Its rounded leaves can become very colourful in autumn.Sycopsis sinensis is another related plant. Its winter-borne flowers are golden-yellow to orange and the plant is evergreen.PlantingAs with just about every aspect of cultivation, the more time you put into preparation before planting your trees, the better the results. When you’ve taken great care to choose the right tree and the right place, why rush to plant it?The roots of a tree spread far more widely and deeply that those of a shrub. Dig over the soil to about 300 mm below the depth of the new tree’s root ball and to at least 500 mm greater diameter that its current root spread. This will allow the tree to establish new roots quickly, which will help to boost its growth and help to stabilise it. Dig in plenty of fine compost to improve the soil texture and increase its moisture retention. If you live in an area with a hard clay sub-soil use a crowbar or a pick to break up the clay or you may find that your trees start to suffer from poor drainage and impeded root development once their roots strike the clay.Remove the tree from its container and plant to the same depth as it was in the container. If the tree is bare-rooted rather than container-grown, look for marks on the trunk that indicate the soil level at which the tree was growing in the field. If the surface roots are showing, plant a little deeper, but take care that you don’t bury the union point of grafted or budded trees. Hammer in a stout stake, taking care not to damage the roots. The ground around the tree will need to be trodden down somewhat to firm up the tree, but don’t overdo it; you don’t want to compact down all that laboriously loosened soil.In very dry areas or where the tree must fend for itself it’s often a good idea to make a small ridge of soil around the drip-line of the tree. This ensures that any moisture dripping from the foliage is channelled back to the roots.Allow the tree to establish before adding fertiliser. If you apply fertiliser before the tree begins to grow, it may develop a too compact root system because there is no need for new roots to seek out soil nutrients. Making the tree stable should be your first consideration, staking helps but encouraging a quick root spread is the best way. When you apply fertiliser put it just outside the drip-line and water it in well to encourage the roots to spread downwards and outwards.MaintenanceMaintenance is most important during the first two years after planting. Trimming to shape, loosening ties and restaking, fertilising and watering are all necessary to ensure that your trees get the best start.Unless you intend to train a tree to a specific shape or style of growth, the pruning of young trees is generally just a matter of removing any damaged branches and those that are likely to head off at strange angles. Garden trees often look better if they’re allowed to develop naturally, just aim to maintain a clean trunk with good canopy development, there’s no need to prune to a perfectly straight trunked forestry specimen.A young, newly planted tree with a large head of foliage is very likely to be damaged by the wind, either directly damaging through broken branches or by wind rocking damaging the roots. Young trees must be firmly staked, but staking can cause problems too. Young trees have soft bark that is easily damaged if it continually rubs against a stake or against the ties that hold the tree to the stake. As the tree grows the stake and ties may cut into the bark. Use ties made of a soft material that breaks down with time and regularly check that the ties are still slightly loose and the stake is not rubbing on the trunk. The new foam rubber tree ties are excellent and can be adjusted as the tree grows, but strips of old cloth are really just as good and they are biodegradable. Usually the stake can be removed after two years, often sooner, but don’t underestimate the strength of the wind.Young trees will establish more quickly if fed and watered, but as mentioned earlier this is better kept at a subsistence level in order to encourage good root development. Established trees will also benefit from feeding, especially if their roots are at all confined. Use a general garden fertiliser and water it in well.Young trees are usually vigorous growers that are not greatly troubled by pests and diseases. If problems do occur they can be treated just as you would a large shrub. However, large established trees are difficult to treat; they are often too tall safely get to the top of and effective coverage with sprays is all but impossible with domestic gardening equipment. Controlling pests and diseases in large trees is usually an area for professionals.Taking the time to give your trees a good start and looking after them in their early years will not only lessen the work required later on, it will ensure that they will repay you with healthy growth and brilliant colour.

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