The plants are not provided with any support so that they make a thick layer of growth which will cover a wide area of the bank. Plants for such purposes that come immediately to mind are Hedera (ivy), Lonicera (honeysuckle) and various rambler roses, but other vigorous climbing plants can be pressed into service. Specimens of Lonicera japonica halliana, a semi-evergreen honeysuckle, planted at 4ft( 1.25m) apart towards the top of a bank will spread downwards for 15 to 20(4.5 to 6m) and make a thicket of twining shoots producing scented biscuit-coloured flowers from May to October. Another strong-growing Lonicera, grown almost entirely for its foliage, is L. japonica 'Aureoreticulata', with small, oval, golden-dappled leaves which give colour and contrast without being garish. A lesson can be taken from nature in the shape of the mounds of brambles which can be seen in the countryside and through which practically no other plants can penetrate. This effect can be simulated in the garden by planting such rambler roses as Alberic Barbier', 'Albertine' and 'Sander's White'; these forming thick, rounded hummocks up to i2ft(3.75m) across and 5 to 6ft(i-5 to 2m) high. Cultivars of ivy will thrive under trees in dry or damp shade, the large variegated leaves of Hedera colchica 'Dentata Variega-ta' making lively patterns of colour where other plants will not grow. It is sometimes desirable to clothe a very steep slope or cliff face but the gradient makes it impossible to plant in the face itself. A variation of this situation posing similar problems could be planting against a high retaining wall. Here, if it is necessary to suppress weeds, thicker-growing climbers are planted at the top to grow downwards, perhaps i2ft(3.75m) or more. To cover or partially hide a high wall or a cliff, such as in an old quarry, some of the Clematis species can be used. Any of the cultivars of Clematis montana and the exquisitely scented C. flammula would be ideal for the purpose. Parthenocissus quinquefolia is spectacular in the autumn, the leaves, like fingers of orange and scarlet, trailing downwards against brown or lichen-covered stone. Vitis amurensis is also a magnificent sight cascading over in a similar way. Muehlenbeckia complexa drops like a curtain down cliffs facing the sea of our south and west coasts, its small, bright green leaves set against wiry stems. It is equally effective against a wall of concrete. To use a contradiction in terms, it could be said that some climbing plants are seen to better advantage growing downwards than upwards-for example, winter-flowering jasmine, Jasminum nudiflorum. The basement flat of a terraced town house often faces towards a retaining wall of concrete or brick-an ideal position for this jasmine would be on the level above where, if a suitable planting position were available, it could hang over the edge and delight in winter. In certain places a variation in the construction of retaining walls can be allowed for, as shown in Figs.