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 _Spiraea 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 Coignetiae_ 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.