Trees that flower throughout the year

The Silver Wattle (Acacia dealbata) is a native of New South Wales, Victoria and Tasmania. Introduced from the latter in 1820 to Kew Gardens, it was grown in a cool glasshouse for protection but now grows happily in Irish, Cornish and Devon gardens and along the coastal districts of both Sussex and Hampshire where it is, perhaps, at its most successful. However, very severe cold conditions can still seriously affect the health and even cause the demise of a tree.

This evergreen tree can reach some 30m in height in the wild but is confined to a small tree or even a large shrub in this country. The shoots are angled and are covered with a fine white or silvery down, while the leaves are doubly pinnate (leaflets arranged on either side of a central stalk) and some 7-12cm in length.  The main leaf divisions (pinnae) comprise some fifteen to twenty pairs with a further thirty to fifty pairs of linear (long and narrow with nearly parallel margins) leaves attached. All parts of the leaves are covered with the same silvery down as cover the shoots, although not to the same density.

The flowers are yellow, highly fragrant and produced in large groups of globose (shaped like a globe) heads or balls some 10cm long. The flowers open in late winter through to early spring and are followed by seed pods of a blue/white colour some 10cm in length and 5mm across.

The Silver Wattle is sometimes referred to as golden "Mimosa", especially by florists who import large quantities of the foliage from the South of France to use extensively in formal bouquets.

The Aspen (Populus Tremula) is broadly distributed in the temperate zones of the Old World from the Atlantic to the Pacific and the Bering Sea. In China it is represented by a variety and not the pure form. In North Africa it is found only in Algeria while in the British Isles it is at its most prolific in the north and west.

The best known attribute of the Aspen is the perpetual quivering of the leaves which gives rise to the saying "to tremble like an Aspen", and this attribute was much mentioned by writers and poets through the ages. While other Poplars share this form of leaf movement, none perform the trembling action to any degree like the Aspen. The timber from this tree is the mainstay of the match industry.

This Poplar has also featured in folklore. A superstition held in the Scottish Highlands that this tree was the supplier of the wood from which the Saviour's cross was constructed saw the tree held in high disregard. Possibly for similar connectio

ns, the peasants of the north of England viewed this tree with a strong feeling of dislike, bordering on fear.

The Aspen reaches some 17m in height in good growing conditions in this country. The winter buds are a bright brown colour, the young shoots are glabrous (hairless) with the leaves greyish green, round to broadly ovate (shaped like a hen's egg). The catkins are formed in February.

The Cherry or Myrobalan Plum (Prunus cerasifera) is a deciduous, round-headed tree reaching, in good conditions, around 10 metres in maturity. This Cherry or Myrobalan Plum is known only in cultivation but almost certainly derives from the wild Prunus divaricata. In its own right it remains one of the most striking of the true plums. P. cerasifera and its cultivars, 'Pissardii' and 'Nigra', make excellent strong, dense, and colourful hedging material as well as individual ornamental trees.

The young bark is glabrous (hairless) and the leaves range between ovate (broadest below the middle like a hen's egg), oval (broadest in the middle), and obovate (broadest above the middle). These grow to approximately 65mm in length and 30mm in width and are covered with downy hairs along the midrib and veins. The flowers, produced from March, are up to 25mm across, are of the purest white, and are produced both singly or in twos or threes at each bud of the previous year's shoots or crowded onto short twigs and producing dense clusters. Fruits are infrequently produced, but when present are smooth, red in colour, average 25mm in diameter and have small indentions at the junction with the leaf stalk.

Among the best of the available cultivars are:

Prunus cerasifera 'Pissardii'

A popular form producing dark red young foliage, later turning to a deep purple colour. The flowers are produced in great numbers in March and are pink in the bud and white on opening. Again, the fruits are reluctantly produced but when evident are purple in colour. This tree was originally noted by the Shah of Persia's gardener, M. Pissard, sometime previous to 1880 and sent by him to France whence it rapidly spread in cultivation.

Prunus cerasifera 'Nigra'

This is an American form, being originally pinker in the flower, but later fading to a blush as the season progresses and having black/purple shoots and leaves.

The Norway Maple (Acer Platanoides) is a native of continental Europe and is found growing wild from Norway southwards. In England, although not a native, it has been cultivated for many centuries and is one of the most statuesque, hardy and vigorous of the trees introduced into the country.

This Maple has the potential, in good conditions, to reach 20-23 metres in height, thrives in all but the poorest of soils and is hardy. The leaves are bright green on both surfaces and are five-lobed, glabrous (hairless) except for a small tuft of hairs in the axils (the angle formed by a leaf with the stem) of the veins.

When broken, the stalks exude a milky fluid and in autumn the leaves fade and turn to shades of brown, red and yellow.

The flowers are produced in erect branching corymbs (a flat or dome-shaped flowerhead with the outer flowers opening first) in April and are a greenish yellow colour, these followed by stalked pendulous and hairless winged fruits.

This large tree species has produced many cultivars covering fastigiate and columnar habits (upright growing stems), purple and cut-leaved forms and even dwarf and purple-leaved varieties.

The French missionary, Abbe Pere David, after whom it is named, discovered a native of Central and Western China, called Pocket Handkerchief, Dove or Ghost Tree (Davidia involucrata) in 1869. It is fully winter hardy and will grow well in all types of fertile soil. The tree is most conspicuous in May when it is adorned with a fine display of large white bracts that give rise to its commonly held names.

It is a deciduous tree, which in the wild has attained heights of 20m and with a form similar to that of the Lime (Tilia). The young branches are glabrous (hairless) and covered with a glaucous (blue-white or grey-white) bloom which later darkens considerably. The leaves are a vivid green, broadly ovate (broadest below the middle, like a hen's egg) or sometimes more round and are 75mm to 150mm in length. The leaf base is roughly heart-shaped and the leaf apex (tip) is drawn out into a noticeable long fine point. The leaf margins are set with coarse triangular teeth and the upper surface displays an abundance of silky hairs, while the underside has thick grey down. The new young leaves are produced on the previous year's shoots and are highly fragrant.

The flowers are produced, crowded into a small rounded head around 20mm across, in May, along with the new leaves. These are borne on the ends of a drooping stalk some 75mm in length. However, it is not in the flowers where the beauty of the Davidia lies, but in the enormous bracts that attend the true flowers. These range from white to creamy-white, hooded around the flowers and roughly oblong-shaped with a long pointed apex. The bract consists of two sections, the upper some 100mm long, raised above the flowers in umbrella fashion, with the lower drooping to 200mm below. The fruit is a single drupe (juicy flesh around a stone) about 35mm long. This is initially green with a purple bloom later turning to russet sprinkled with red when fully ripe and contains a hard ridged nut with five seeds.

Indian Horse Chestnut (Aesculus indica) was introduced into this country by Colonel Henry Bunbury in 1851 and a seedling planted in a relative's garden at Barton in Suffolk had reached an estimated height of some 20m by 1904. Another plant grown there was recorded to have flowered when only seven years of age.

A native of North West Himalaya, this tree can reach heights in excess of 30m in the wild, although considerably less in the United Kingdom where it has been infrequently planted since its introduction. In the south, this tree grows well on chalk soils, but can only be recommended for planting in large private gardens, public parks and open spaces, with Wakehurst Place in Sussex and Worthing's Highdown Gardens being places locally to view this tree. The tree is generally winter hardy but young growths may be retarded by late fosts in low lying areas.

This tree often produces a short but enormously thick trunk and old specimens have the noticeable characteristic of the bark peeling off in long strips without detriment to the tree's health. The winter buds are resinous and on opening produce toothed leaves composed of seven leaflets which are glabrous (hairless) on both surfaces and obovate (broadest above the middle) to lanceolate (lance-shaped), the central leaves being the largest, up to 30cm in length and 7cm in width. On emergence, the leaves are of a bronze colour, turning to dark green as they mature and finally to orange and yellow in autumn.The flowers are carried in erect, cylindrical-shaped panicles (branched elongated inflorescence with stalked flowers) up to 40cm long and are white with four petals. The longest petals are marked by a blotch of yellow and red at the base of each, while the two shorter petals are flushed with a pale rose. The fruit has a rough texture but is not spiny like the fruit of Aesculus hippocastanum, the Common Horse Chestnut.

This tree flowers in June and is, therefore, a month ahead of the Common Horse Chestnut.

The Tulip Trees (Liriodendron tulipifera) are related to the genus (group of plants with common characteristics) Magnoliaceae, the Magnolias, but differ in the fact that they never have a pointed leaf, their terminal buds (formed at the end of twigs) are of a different shape and their seed vessels are closed.

The original trees were found in North America and records prove that this was cultivated in Fulham, England by Bishop Compton, as far back as 1688.  Originally, the North American Tulip Tree was thought to be monotypic (a single species or genus). However, a related form, Liriodendron chinense, was found in 1875 growing at altitude in the Lushan Mountains of China.

The North American form reaches considerable size in its native environment with heights of 60m and trunk diameters of 3m not uncommon. The largest specimens in England have been recorded at approximately 33m. The leaves are distinctly unique, being large, saddle-shaped and with the apex (tip) being very broad and 'cut off' almost square.

The tulip-shaped flowers are produced in late June, but mostly July. The petals are oblong, 3 or 4cm long, erect and overlapping to form a cup or tulip shape.  The colour is a greenish-white with an orange spot at the base. The centre contains a large pistil (female organ) surrounded by numerous stamens (male organs). The leaves turn a rich butter yellow in autumn.

In its wild state, the Tulip Tree extends from Nova Scotia to Florida and, as well as being much prized as a specimen garden tree for its leaves, flowers and large trunk, the timber is extensively used. This cut timber sold under the name 'White Wood' is used for many indoor uses and, while not being a strong timber, does not split readily. It is close-grained, smooth, and yellow in colour.

The Indian Bean Tree (Catalpa bignonioides) are a native of the eastern United States of America, introduced to Britain in 1726. Although only faring well in southern counties, the Indian Bean is a superb tree of large leaf form and striking blossom during the flowering period.

It is a small to medium-sized deciduous tree, usually from 8m to 16m in height and, in tree terms, relatively short lived, declining from 40 to 50 years of age.  The tree does not form terminal buds and this appears to dictate its eventual wide spreading and bushy topped habit when planted away from encroachment from neighbouring trees.

The leaves are large, broadly ovate (broadest below the middle like an egg) with a pronounced heart-shaped base and measuring some 10cm to 25cm in length and between 7cm to 20cm in width. The young leaves of juvenile trees can grow considerably larger. The leaves are light green and glabrous (hairless) above and with a clothing of hairs over the underside of each leaf.  When crushed, the leaves give off an unpleasant and disagreeable smell. The mass of flowers are produced in pyramidal shaped panicles up to 25cm in both length and width with each corolla (the inner conspicuous part of a flower, the petals) being some 35mm in width and length with frilled margins and with a bell-shaped tube. The flowers are essentially white with two ridges and two rows of yellow spots, and numerous purple spots on the tube and lower lobe.

In hot seasons the tree produces an abundance of fruit and a tree festooned with the long pendant seed pods has a curious aspect. The pods are slender, variable in size from 15cm to 45cm in length, round and as thick as a standard pencil.

Following its introduction from America, other forms of the genus were later introduced from China. However, staying with Catalpa bignonioides, the following cultivars are perhaps of interest:

• cv. 'Aurea': Striking rich yellow leaves staying true to the colour for the whole of the season and actually improving as the season progresses.
• cv. 'Koehni': Leaves yellowish green in the centre, with a wide margin of yellow.
• cv. 'Nana': A dwarf form up to 2m in height with bushy habit, much smaller leaves and reputed never to flower.

The genus Eucryphiaceae (a group of plants with common characteristics) consists of four species (plants within a genus), two being native to Chile and two native to Australasia, and four hybrids (the offspring of two different species or varieties). All are of great interest and beauty, although only Eucryphia x nymansensis is considered suitable for planting in the local area with any high degree of success in establishment.

Eucryphia x nymansensis is a hybrid between two Chilean species, E. glutinosa and E. cordifolia. It is an evergreen tree of fine erect shape, reaching a height of 17m, with leaves that are intermediate between those of its parents, both simple and compound (composed of at least two parts) leaves appearing on the same plant. The leaves are firm and leathery in texture with the compound leaves being almost trifoliate (leaf with three separate leaflets). All leaves have regular toothed margins with a dark shining upper surface and a dull underside, both of which are covered in a slight down.

The flowers begin to open in late August and are showy throughout September. They are large at 6cm across with four petals and are pure white. The numerous yellow stamens accent and complement the whiteness of the flowers.

This cross first arose at Nymans Gardens at Handcross in Sussex and originated from seed sown in 1914 by the founder of the gardens, Leonard Messel. A little after the end of the Great War, the late Lt Colonel L C R Messel gave several plants to his friends. Among these was Sir Frederick Stern, the founder of Highdown Gardens in Worthing, West Sussex (where is still grows well on the lime rich soils), who received his plant in 1919 and recorded it flowering by 1922.

While tolerating lime soil, the tree needs high soil moisture and does not stand extreme winds which cause serious debilitation generally and prevent establishment in young trees. Ideally, a light sheltered position is required to encourage the tree to become established and flower.

Magnolia grandiflora was introduced from the southern United States early in the 18th century. It is an evergreen tree with the potential for heights of 20m or more. However, in Britain 10m is more normal. The tree produces a dense pyramidal form with leaves oval (broadest in the middle) to oblong (longer than broad with near parallel sides) some 15cm to 25cm long and less than half this distance in width, tapered at both ends. The leaves are leathery, dark green and glossy above, and covered beneath with thick red brown felt, this especially noticeable in young plants. The leaf stalk is variable in length between 2.5cm and 5cm.

The flowers of Magnolia grandiflora are among the finest of all Magnolias, being globular and up to 25cm across. The flowers are highly scented with a pleasant spicy/fruity quality and are produced continuously during late summer into autumn. The petals are thick, concave (curving like the inside of a ball, viewed from the inside) and coloured creamy white.

The genus Magnoliaceae (a group of plants with common characteristics) consists of a group of evergreen shrubs and trees named by Carl Linnaeus, a Swedish naturalist, in honour of Pierre Magnol, a professor of botany at the botanical gardens at Montpelier and physician to Louis XIV.

The genus is most numerous in Eastern and South Eastern Asia with over one-quarter of the species natives of the New World, from North Eastern United States to northern South America. Over half of the species (plants within a genus) are tropical, but of the temperate (having a mild climate) species, almost all have been introduced to Britain at some time.

This deciduous ornamental Cherry, a native of Japan, derives its name from the Latin, subhirtella, meaning 'somewhat hairy' and its cultivar (a variety of plant produced by cultivation) name 'Autumnalis', meaning 'of Autumn'.

It would seem that 'Autumnalis' was distributed commercially in this country by the Daisy Hill Nursery around 1910, but a tree imported directly from Japan was planted at Borde Hill Gardens, West Sussex, some ten years earlier. This was reputed to be the largest specimen in this country until being destroyed by a falling tree during the 1960s. P subhirtella 'Autumnalis' received the Royal Horticultural Society's Award of Merit in 1912 when it was shown as Prunus miqueliana.

This small tree reaches a height of approximately 7m with a spreading habit often as wide as it is tall. The flowers are semi-double, some 2cm across and pink while in the bud stage and produced in clusters of two to five. On opening, the emerging flowers are almost white and produced for much of autumn, from November and into the spring.

The leaves are long, up to 75mm in length with a leaf stalk of approximately 5mm, ovate, (broadest below the middle like a hen's egg) taper-pointed towards the end and double-toothed. The midrib and veins under the leaf are downy. The leaves are bronze coloured when young, turning more green with maturity and have an attractive yellow colouring during autumn prior to leaf fall. The flowers are produced in abundance after the autumn leaf fall, with the white blossom contrasting with the bare stems of the canopy to great effect.

The genus (group of plants with common characteristics) Prunus comprises over 200 species (group of plants within a genus) of evergreen and deciduous trees and shrubs ranging in distribution from northern temperate regions, the Andes of South America and the mountains of south-east Asia. Plants within the genus can be found growing in a wide range of habitats from woodland thickets to coastal, sandy and rocky habitats.

As well as the ornamental value of their blossom, the genus includes many providers of seasonal fruits including Plums and Apricots, Cherries and Peaches and also Almonds. However, it is for its ornamental contribution that we consider the Rosebud or Autumn Cherry, especially for its cheerful defiance of the coming of winter.