CHAPTER X

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; _Koelreuteria 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.

CLIMBERS

First among these, of course, is Veitch's Ampelopsis, the finest of all deciduous climbers for walls, being self-supporting and changing to crimson in autumn. _Vitis Coignetiæ_ is one of the noblest of all Vines, and turns crimson also. Other Vines useful in this respect are the Teinturier Vine, purple; _V. Romaneti_, red; and the Virginian Creeper, especially that variety known as _muralis_ or _Engelmannii_, which clings to walls or tree trunks without any artificial support, and acquires beautiful red shades in autumn. Among Honeysuckles, _Lonicera japonica var. flexuosa_ is noteworthy for the fine red purple of its decaying leaves. Those of _Akebia quinata_ change colour in autumn and assume shades of brownish purple, sometimes touched with maroon. Then there is _Actinidia Kolomikta_, an Asiatic species with showy yellow-coloured leaves in autumn. Of the Ivies _Hedera Helix atropurpurea_ is much the best. It has medium-sized leaves which are rich green during the growing season, but change in winter to purple and maroon.