Trees and Shrubs for English Gardens

by E. T. Cook

AUTUMN COLOURS

There is a mystery about the autumn colouring of the foliage of our many beautiful hardy trees and shrubs in this country, and we have never yet ascertained with any degree of exactness the conditions that produce the richest and brightest tints. Probably the conditions most favourable generally are provided by a good growing season—that is, a warm, moist summer—followed by a dry, sunny autumn. But it frequently happens after what one would regard as favourable seasons, that species which are usually quite trustworthy in this matter fail to colour well. Probably one set of conditions does not suit all trees and shrubs in this respect. To produce the colouration of the leaf just before it falls certain subtle chemical changes in its composition take place. And to bring about these changes certain conditions in regard to sunlight, temperature, and moisture are necessary. But in a climate such as that of Britain, where the seasons are never alike two years together, we can never hope to obtain the same regularity of autumnal colouring that characterises the vegetation, for instance, of the Eastern United States. Still, when all is said, we possess in our gardens a large number of trees and shrubs and climbers that are delightful in their autumnal livery of crimson, purple, scarlet, or gold. It is curious that every season we may notice species not usually conspicuous for their autumn tints beautifully coloured.

An over-vigorous, sappy growth, often the result of a wet, warm autumn or too rich a soil, is certainly detrimental to autumn colouring. Rhus cotinoides, an American Sumach, worth growing for the beauty of its colours in autumn, is one of the most unfailing in this matter. This is perhaps one of the loveliest of all autumn-tinted shrubs, and should be more planted. But young plants, put out in well-trenched, heavily-manured soil, will often fail to colour at all till they get older and less vigorous. The most beautifully coloured examples of this Sumach that we have seen grow in rather light sandy soil. We have frequently noticed, too, that various species of Vine (Vitis) when starved in pots will colour exquisitely, whilst others, planted out in the ordinary way, completely fail. We believe, therefore, when planting with a view to the production of autumnal colour, any great enrichment of the soil is neither necessary nor advisable, provided it is of moderate quality to start with.

In the following notes, brief mention is made of some of the best trees, shrubs, and climbers that colour in autumn:—

Trees

First among these are the American Red Oaks. Undoubtedly the best of these is a variety of Quercus coccinea known as splendens and grayana. This not only turns to a fine scarlet crimson, but it retains its foliage for some weeks after the colour has been acquired—sometimes almost up to Christmas. Other good Oaks, not so certain, however, as the preceding, are Quercus marylandica (or nigra), Q. heterophylla, Q. imbricaria, and Q. palustris, all of which turn red. The Tupelo tree (Nyssa sylvatica) turns a fine burnished bronzy red. A tree remarkable for the size of its leaves, and especially for the rich golden yellow they put on in autumn, is Carya tomentosa, but, like most of the Hickories, it is scarcely known in gardens. Carya sulcata is somewhat similar. The Common Elm is usually very beautiful in the soft yellow tints of its leaves in autumn, but another Elm of more distinct aspect is Ulmus pumila, a low tree whose small leaves are retained till late in the year, and turn golden yellow before they fall. Liquidambar styraciflua has long been valued for its fading foliage of purple red, but not so well known is the lovely yellow of the Fern-like foliage of the Honey Locust (Gleditschia triacanthos). The Tulip tree (Liriodendron), the Nettle trees (Celtis), the Zelkowas, and several of the Birches turn yellow, one of the best of the Birches being Betula corylifolia, which turns a rich orange yellow.

Among commoner trees the yellow of the Horse Chestnut, the lovely crimson of the Wild Cherry, the golden shades of the Black and Lombardy Poplars, add much to the beauty of every autumn. Several of the Maples are noteworthy in this respect, more especially the numerous varieties of Japanese Maples (Acer palmatum and A. japonicum), these, as well as the Mandshurian Acer Ginnala, turning to various shades of red. The Common Sycamore and Norway Maple change to yellow, but Schwedler's variety of the latter becomes red. Other trees that deserve mention are Amelanchier canadensis, whose foliage changes to lovely crimson shades in autumn; Kœlreuteria japonica, soft yellow; Pyrus torminalis, bronzy red; Ginkgo biloba, pale gold; Cladrastis tinctoria, yellow; Parrotia persica and Hamamelis, bronzy red and yellow. The Common Beech is nearly always beautiful, changing first to yellow, then to warm brown tints. Clerodendron trichotomum is a small growing tree that should have a place wherever beautiful autumn foliage is desired. Among Conifers the yellow-leaved variety (aurea) of the Scotch Pine is remarkable in retaining its colour during the winter months only, becoming green in spring and summer. Retinospora squarrosa and Cryptomeria elegans turn bronzy red in winter. The warm red-brown tints of the deciduous Cypress are charming.

Shrubs

The Sumachs (Rhus) furnish some of the most striking of autumn-colouring shrubs; the best of them, R. cotinoides, has been already described; other fine species are R. typhina, R. glabra (with the cut-leaved variety laciniata), and R. Toxicodendron, all of which turn red. The Venetian Sumach, R. Cotinus, becomes yellow. Berberis Thunbergi, which dies off a rich scarlet, is so beautiful in autumn that on some estates it has been planted in great quantity, not only for cover, but so that sportsmen may enjoy its colour during the shooting season. B. concinna is another charming autumn-coloured leaved shrub of dwarf growth. Gaultheria procumbens (Partridge Berry) is too valuable to pass unnoticed. In winter its leaves are stained with crimson. The leaves of Cotoneaster horizontalis turn from green to rich shades of chocolate or crimson. The shrub is of spreading growth. Its evergreen ally, B. Aquifolium, turns a glowing red or purple after the first frosts. The Ghent Azaleas almost always colour richly, either deep glowing crimson, bronzy red, or gold; and of other ericaceous plants the warm tints of Pieris mariana and the rich crimson of the Enkianthus should be mentioned. The taller American Vacciniums (corymbosum and its various forms) are always lovely. Our native Guelder Rose (Viburnum Opulus) becomes crimson in autumn, whilst the Common Hazel and Rhamnus Frangula often produce fine effects in yellow. The feathery foliage of Spiræa Thunbergi is singularly beautiful when it changes from its natural pale green to crimson; and S. prunifolia fl. pl. is perhaps more distinct than the species, and two other Japanese shrubs (both, unfortunately, very rare) are remarkable for their autumnal beauty. These are Disanthus cercidifolia, an ally of the Witch Hazels, lovely claret colour, and Viburnum alnifolium, crimson.

Other noteworthy shrubs are Fothergilla alnifolia, rich red; Euonymus alatus, crimson; Deutzia crenata, yellow; and Pyrus arbutifolia, red. The common Brambles of our woods should not be passed over without mention; they turn a rich glowing red, and for their autumnal beauty alone may be used as undergrowth in wilder parts of the garden and woodland.