As a general rule, we strongly advocate planting in groups, whether in the case of trees, shrubs, or flowering plants, but the weeping trees are less suited for grouping than any others. One Weeping Willow is all very well, but a whole grove of them would be monotonous and tiresome.

[Ill.u.s.tration: _ELaeAGNUS PUNGENS (Kew)._]

The habit of some of the weeping trees can be directly turned to account in the making of arbours and pergolas; for by planting the large-leaved Weeping Elm or the Weeping Ash at the back and on each side in the case of an arbour, or alternately on each side of the walk for a pergola, a living shelter may be made in a very few years. The trees in this case are standards pollarded at about 8 feet from the ground, the form in which they are generally sent out from the nursery.

[Ill.u.s.tration: _CORNUS MAS VAR. VARIEGATA (Variegated Cornel)._]

Among evergreens the Holly is invaluable. As a rule the weeping or pendulous varieties are budded on tall stems of the type, and trained out in an umbrella-like fashion, thus forming a hollow mound of greenery. In some places, notably at Brookwood in Surrey, pendulous Hollies have been allowed to grow without any attempt at training. Stout stems 10 feet to 12 feet high are surmounted by irregular heads, which droop down 6 feet or 7 feet, leaving several feet at the base of the stem bare. In winter the long pendulous branches, smothered with bright red berries, are very pleasant. Facing page 248 is an ill.u.s.tration of a weeping Holly (_I. Aquifolium var. pendula_) at Kew. Of variegated weeping Hollies there are _Argentea pendula_ (Perry's Weeping), with silver variegated leaves; _aurea pendula_ (Waterer's Weeping), with gold variegated leaves; and _pendula tricolor_. To encourage height rather than width, it is often necessary to tie up a few of the top shoots, otherwise they get out of shape; they increase more quickly in width than height.

(i.) NATURALLY PENDULOUS SPECIES AND VARIETIES, _i.e._ COMING TRUE FROM SEED

_Asterisk denotes those to choose first._

Tilia (Lime or Linden) petiolaris.

Genista aethnensis (shrubby).

* Prunus pendula (Weeping j.a.panese Cherry).

Forsythia suspensa (shrubby).

* Salix (Willow) alba caerulea pendula.

,, ,, vitellina pendula.

* ,, ,, babylonica.

,, ,, ,, annularis.

,, ,, ,, Salamoni.

,, ,, elegantissima.

(ii.) PENDULOUS VARIETIES THAT HAVE ORIGINATED AS "SPORTS," PROPAGATED BY GRAFTS, CUTTINGS, OR LAYERS

* Ilex (Holly) Aquifolium (green and variegated).

Acer (Maple) Negundo pendula.

Rhus Cotinus pendula.

Laburnum vulgare pendulum (Weeping Laburnum).

Cytisus scoparius pendulus.

Caragana (Pea tree) arborescens pendula.

Sophora j.a.ponica pendula.

* Prunus Amygdalus pendula (Weeping Almond).

* ,, Avium pendula (Weeping Wild Cherry).

,, acida semperflorens.

* ,, Mahaleb pendula (Weeping Mahaleb Cherry).

,, Padus pendula (Weeping Bird Cherry).

* Crataegus Oxyacantha (Hawthorn), red and white flowered.

Sambucus nigra pendula (Weeping Elder).

* Fraxinus excelsior pendula (Weeping Ash).

,, ,, aurea (golden-leaved) pendula.

,, ,, pendula wentworthii.

,, parviflora pendula.

Ulmus (Elm) americana pendula.

,, ,, campestris pendula.

,, ,, ,, antarctica pendula.

,, ,, ,, suberosa pendula.

,, ,, fulva pendula.

* ,, ,, montana pendula.

,, ,, ,, Pitteursii pendula.

Morus (Mulberry) alba pendula.

* Betula (Birch) alba pendula.

* ,, ,, ,, Youngi.

,, ,, ,, purpurea pendula.

Alnus (Alder) incana pendula.

Carpinus (Hornbeam) Betulus pendula.

Corylus Avellana (Common Hazel) pendula.

Quercus (Oak) pedunculata pendula.

,, ,, rubra pendula.

* f.a.gus (Beech) sylvatica pendula.

,, ,, ,, miltonensis.

,, ,, ,, remillyensis.

* Salix (Willow) Caprea pendula.

* ,, ,, purpurea pendula.

,, ,, ,, Scharfenbergensis.

,, ,, repens argentea.

* Populus tremula (Aspen) pendula.

* ,, tremuloides pendula.

* ,, grandidentata (American Cotton Poplar).

(iii.) CONIFERS

Cupressus lawsoniana glauca pendula.

,, ,, gracilis pendula.

,, ,, pendula vera.

,, ,, gracillima.

,, nootkatensis pendula.

Cedrus atlantica pendula.

Ginkgo biloba pendula.

Juniperus (Juniper) virginiana pendula.

Larix europaea (Common Larch) pendula.

Thuya orientalis pendula.

,, flagelliformis.

Taxodium distichum (Deciduous Cypress) pendulum.

Tsuga canadensis pendula.

Taxus (Yew) baccata pendula.

,, ,, ,, gracilis pendula.

,, ,, ,, Dovastoni. There is a fine specimen of this in Barron's nursery at Borrowash.

CHAPTER XIII

THE USE OF VARIEGATED TREES AND SHRUBS