SHRUBS UNDER TREES
It is often a vexed question what to plant under trees when the space is
bare, and sometimes there is an ugly view seen beneath the branches to
shut out. Evergreens are the sheet anchor, relieved with a few deciduous
shrubs grouped amongst them.
Much depends upon the tree, whether a Beech or an Oak, a Maple or a
Chestnut, and so on, as trees vary considerably in their method of
rooting, as well as in the shade they give during the summer months.
This affects the welfare of the plants underneath. Such trees as Oak,
Ash, Plane, Birch, and Horse Chestnut are inclined to root deeply when
they have grown to a fair size, and do not interfere directly with
anything underneath them, although the roots extract much moisture from
the soil.
On the other hand, Beech, Elm, Lime, and Sycamore are more
surface-rooting, and their roots often get entangled with and gradually
kill plants growing near them. Beech and Elm are the greatest offenders,
and grass frequently perishes under these trees. A few liberal soakings
of water in dry weather are beneficial to shrubs or anything else under
trees, but the soakings must be thorough, as mere sprinkles are more
harmful than otherwise. The spread of large tree branches should also
be noticed in summer, as sometimes one or two of the lower ones may be
removed with benefit to the shrubs, judicious cutting away letting in
light and air.
The best of the larger growing evergreens to use under trees are
Laurels, both common and Portugal, Yews, Box, Osmanthus, Aucubas,
Phillyraeas, common and oval-leaved Privet, _Ligustrum sinense_, and
_Rhododendron ponticum_. Of these Yews, Box, and Osmanthus are perhaps
as successful as any. The Osmanthus is not usually considered suitable
for this purpose, but it succeeds well in the shade, and keeps a good
dark-green colour. Hollies are sometimes recommended, but, though they
may occasionally thrive under trees, it is not advisable to use many of
them, as they are more often a failure, becoming thin and straggling in
the course of a year or two. Of dwarf-growing evergreens _Berberis
Aquifolium_, Butcher's Broom (_Ruscus aculeatus_ and _R. Hypoglossum_),
_Cotoneaster microphylla_, _Euonymus japonicus_, and _E. radicans_, with
their respective varieties, Skimmias, _Gaultheria Shallon_, Ivies,
especially the common English, Irish Ivy, and Emerald green, _Pernettya
mucronata_, St. John's Wort (_Hypericum calycinum_), and Vincas can all
be recommended, as they all do well in the shade, and most of them will
flower freely.
For a very dry spot where nothing else will grow the Butcher's Broom and
St. John's Wort should be planted, as both will grow and thrive where
other plants die. With deciduous shrubs under trees the difficulty is
not so much in getting them to live as in coaxing them to flower, but a
few of them will do well in the shade, and, as a rule, bloom freely. Of
these the best are the common and White Brooms, _Azalea pontica_,
_Genista virgata_, _Philadelphus_, Forsythias, and _Daphne Mezereum_.
The shrubby Spiraeas may also be used sparingly in a fairly light and
open place, though plenty of sun is required as a rule to enable them to
flower properly. In addition, though their flowers are insignificant,
_Cornus alba_ with its red stems in winter, the Snowberry
(_Symphoricarpus racemosus_), which is laden every year with white
berries long after the leaves have fallen.
The question about shrubs growing under trees is so frequently asked
that the names of those most successful are given, but generally the
beauty of the tree is lost when smothered up with evergreens and other
shrubs beneath its spreading branches. A tree is a picture in itself,
and it is pleasant to see the grass creep to the branch edge and then
cease, leaving a brown earth patch under the canopy of foliage.
Shepherdi Holly, Tree Ivies, and _Berberis stenophylla_, it may be
mentioned, are a success under trees.