Of the taller Heaths, E. lusitanica is somewhat tender, and is not so generally useful as E. mediterranea or E. arborea (Tree Heath). A hybrid form—E. mediterranea × E. carnea—is excellent, and comes into flower about Christmas, in advance of either of its parents, when its pale-purple spikes are very welcome, and are quite distinct from the rosy-red flowers of E. carnea: it is known as E. mediterranea hybrida. The foliage of hardy Heaths is never unsightly, but the persistent dead flowers are, and these should always be clipped off as soon as their beauty is over, or the new growth will break away above the withered flowers, leaving, in many cases, straggling and unclothed branches. The omission of this needful work every season is a fruitful source of the raggedness which brings some discredit on these otherwise attractive plants.

Many flowering shrubs of the same natural order as Heaths, but unlike them in general appearance, such as the Alpine Rhododendrons, R. ferrugineum and R. hirsutum, and the less well-known but very beautiful and distinct R. racemosum, as well as some of the miniature varieties of Azalea indica, notably R. obtusa and its forms, seem peculiarly suitable for the Rock Garden (see p. [428] for lists of the best Rhododendrons). Again, where rock meets more level ground, and the trickle of a stream can be so directed as to give moisture without sogginess, a considerable number of peat-loving evergreen shrubs belonging to the same order, of the type of Gaultheria, Vaccinium, and Pieris, may be used with excellent effect. Gaultheria Shallon, indeed, is a singularly fine shrub in any position, and is not very exacting in any of its requirements. Growing about 2 feet high, with purple leaf-tints in winter, and spikes of white waxy flowers, brightly tinged with red, in spring, which are followed by purple fruit, few things can surpass it in its way. For carpeting moist spots, the little G. procumbens, which rises scarcely 3 inches from the ground, will fill a useful place with its winter colouring of crimson brown. Shrubs of this class are well worth study by those whose locality admits of their cultivation.

For dry, sunny, and stony banks Rock Roses may be chosen, but the position must be wind-screened, a more important factor in the question of their hardiness than cold. The large-growing Gum Cistus is well known and tolerably hardy everywhere, and so also is C. laurifolius, but there are several most desirable species of dwarfer growth, such as the white, crimson-spotted C. lusitanicus, the pink-flowered C. villosus, the bright-red C. crispus, and the pure white C. florentinus, which are quite happy in sheltered rock walks especially by the sea; they have been also grown with success in many colder situations inland. The Cistineæ, at best, are somewhat short-lived, and lose vigour and power of resistance as they grow older. Keep up, therefore, young, thrifty stock by yearly cuttings to fill up inevitable gaps, which is a matter of no cultural difficulty. Where Rock Roses are out of the question, their place may worthily be filled by the hardier shrubby Helianthemums, though they differ greatly from Cistineæ in their trailing habit and smaller flowers. The breadths of brilliant colour given by these Sun Roses while in bloom are invaluable, and may be enjoyed to the full in almost any locality, while the many variations of tint, from deep green to ashen grey, in their leafage should also be taken into consideration, as it increases their usefulness when out of flower.

No list of good shrubs for the Rock Garden would be complete without some reference to Yuccas, which for all practical purposes must be included under that head. Groups of these magnificent plants, with their sub-tropical effect, cannot be surpassed for nobility of outline and stateliness of flower. To do them full justice, they must have space to develop their grand proportions, but this may often be found on the ridge or upper slope, even in rock-work of limited character. Y. gloriosa, with its fine form, Y. recurva, and the stemless Y. flaccida, of smaller growth, are amongst the best and hardiest kinds, and to these may be added Y. angustifolia, another valuable and nearly stemless species.

It is only possible, in restricted space, to touch in a very cursory way upon a few of the available groups of dwarf-growing shrubs. Many more than have been mentioned will occur readily to the minds of those who are at all conversant with plants, such as Abelia rupestris, Magnolia stellata, several beautiful species of Daphne, some of the St. John's Worts, of low-growing Cytisus, and others which may be classed under the head of miscellaneous. The subjoined list, though it does not pretend to be exhaustive, will be found of use, either for purposes of winter greenery or for summer embellishment, by those who are seeking good and suitable dwarf shrubs for planting, under varied conditions in the Rock Garden.

DWARF SHRUBS FOR THE ROCK GARDEN

Hardy Evergreen

Conifers