ROCK- GARDEN 



The importance of protection from drying and cold 

 winds and of securing shade in many situations must 

 not be overlooked. Sometimes advantage mav be 

 taken of an existing deciduous or evergreen tree or shrub 

 growth, or rapid-growing varieties may be planted to 

 make a screen. While shelters of this character are of 

 value about the outer limits of a rock-garden, they can 

 hardly be used for separating its smaller compartments. 



ROCK-GARDEN 



2971 



3417. An isolated rock-garden under a tree, southern California. 



For this purpose, slow-growing dense-foliaged ever- 

 greens with a restricted root range are best. This 

 would include the yuccas, a few of the dwarf forms of 

 thuya, juniperus. picea, retinispora and practically all 

 the broad-leaved evergreens. The latter, especially the 

 rhododendrons (of which Rhododendron maximum can 

 be secured in large plants at low cost), are particularly 

 useful owing to their habit of growth, restricted root 

 area, and the facility with which they can be moved 

 from place to place as desired. As these shelter-belts 

 and groups form the background and setting of the 

 rock-garden and are the dominating landscape feature 

 in views from a distance, their composition and dis- 

 position is a matter of much importance. The disposi- 

 tion must be governed, however, by the general arrange- 

 ment of the ground, but in this arrangement an agree- 

 ably varied sky-line and composition of plant forms 

 and of shades of green should be sought for. In the 

 composition of the background, and in the planting 

 of the rock-garden as well, a decided character should 

 be given to the whole and to each distinct compart- 

 ment by using some few effective plants in quantity 

 rather than a great number of varieties in small quan- 

 tities. Variegated and distorted garden freaks should 

 be excluded, for they only distract the attention from 

 the rock-garden, the primary object. Even more inap- 

 propriate are statuary fountains and vases. 



Up to this point reference has been made for the most 

 part to distinctly alpine plants, that is, plants that are 

 confined exclusively to the region on mountains above 

 the tree- and shrub-line. They are the ones that will 

 test the skill of the cultivator. There are, however, 

 many rock-plants, that is, plants that grow naturally on 

 rocks, or plants having a tufted, matted, and more or 

 less persistent and evergreen foliage similar to alpines, 

 that can be used with them in less favorable positions 

 in the rock-garden or in the open border. Many of such 

 plants can be readily procured from American nursery- 

 men and collectors. They are easy of cultivation and 

 attractive in habit and flower. The writer would include 

 also low-growing bulbous plants, especially such as have 

 inconspicuous foliage. They may be planted with the 

 low ground-covering plants to push up through them. 

 From this list are omitted such plants as belong more 

 properly in the wild-garden, especially such as spread 

 rapidly by underground shoots and are likely to become 

 a pest. (In a rockery conditions are such that it is 

 almost impossible to extirpate deep-rooting, weedy 

 plants, and they above all others should be rigidly 



excluded.) Among desirable rock-plants may be 

 included Geranium sanguineum, G. Andrewsii, and 

 G. Robertianum, GypsophUa muralis, Helianthemum 

 vulgare, Hetteborus niger, Leontopodium alpinum, Lin- 

 aria Cymbalaria, Lotus corniculatus, Lychnis Viscaria, 

 Papaver alpinum and P. nudicaule, Ceratostigma Lar- 

 pentse, Saponaria ocymoides, Veronica Teucrium and 

 V. rupestris, Arabis alpina, Campanula fragUis, Daphne 

 Cneorum, species of Alyssum. Bellis, Cerastium, 

 Arenaria, Draba, Epimedium, Iberis, Thymus, Arabis, 

 Armeria, Ajuga, Dianthus, Sedum, Sagma, Primula, 

 Aquilegia, Saxifraga, Corydalis, Myosotis, Semper- 

 vivum, Parnassia, Viola, Hepatica, Opuntia, Houstonia, 

 Anemone patens var. Nuttattiana, dwarf and creeping 

 Campanulas, Cornus canadensis, Dicentra eximia, 

 Calluna vulgaris, Iris cristate, 7. verna, and 7. pumila, 

 LeiophyUum buxifolium, Phlox subulata, P. amaena, 

 and P. reptans, Saxifraga virginiensis, SUene pennsyl- 

 vanica and S. virginica, Anemone thalictroides, Wald- 

 steinia fragarioides, Galax aphytta, Asperula odorata, 

 low-growing ferns, mosses, and the like. 



For more specific instructions as to the construction 

 of rock-gardens and the care and propagation of rock- 

 plants (for European conditions), see Robinson's 

 ''Alpine Flowers," London, 1870, and Sutherland's 

 "Hardy Herbaceous and Alpine Flowers," Edinburgh 

 and London, 1871. WARREN H. MANNING. 



The making of a rock-garden. 



A rock-garden must of necessity often be "artificial" 

 in the sense of made by man, because few gardens or 

 grounds contain a natural rocky slope or even a natural 

 bank upon which one might be constructed, and if they 

 did the position may not be an ideal one. A southern 

 slope would be too hot and dry in this climate, unless 

 it was shaded by tall trees. A bank with a northern or 

 northeastern aspect free from the roots of trees would 

 suit this class of plants much better, and very attrac- 

 tive it can be made, especially if the bank is on the 

 outer edge of a garden, or skirts a lawn. There is no 

 form of gardening in which one has more opportunity to 

 give expression to his natural taste than in the con- 

 struction and planting of a rock-garden. But since all 

 grounds or gardens do not have a natural bank or 

 slope upon which an "open" rock-garden might be 



3418. A picturesque rockwork for the wilder parts of the grounds 

 (European). 



constructed, a depressed rock-garden may be made in 

 grounds that are perfectly level, and some of the best 

 rock-gardens in the world are what are known as 

 "underground," for example, the one in the Royal 

 Botanic Gardens, Kew, London, England. Before this 

 rockery was constructed the ground was perfectly level. 

 A cutting was begun at one entrance, at first shallow, 



