WALL AND WATER GARDENS •M^MHiBHBlHilHHiHHi A GARDEN OF WALL AND WATER, THE " COUNTRY LIFE" LIBRARY. WALL AND WATER GARDENS. BY GERTRUDE JEKYLL. I 1 FOURTH EDITION. PUBLISHED BY "COUNTRY LIFE," LTD. GEORGE NEWNES, LTD. »o, TAVISTOCK STREET, 7-12, SOUTHAMPTON STREET, COVENT GARDEN, W.C. STRAND, W.C. £0/0* PREFACE THERE is scarcely an English country home where some kind of gardening is not practised, while in a very large number of country places their owners have in some degree become aware of the happiness that comes of a love of flowers, and of how much that happiness increases when personal labour and study work together to a better knowledge of their wants and ways. In this book a portion only of the great subject of horticulture is considered, namely, simple ways of using some of the many beautiful mountain plants, and the plants of marsh and water. It is intended as a guide to amateurs, being written by one of their number, who has tried to work out some of the pro- blems presented by the use of these classes of plants to the bettering of our gardens and outer grounds. The book does not attempt to exhaust the subject, neither does it presume to lay down the law. It is enough, in the case of the rock and wall plants, for instance, to name some of the best and easiest to grow. Those who will make such use of it as to 2.4-0103 VI PREFACE work out any of the examples it suggests, will then have learnt so much for themselves that they will be able to profit by more learned books and more copious lists of flowers. The large quantity of pictorial illustration is in itself helpful teaching. " I like a book with pictures " is not only an idle speech of those who open a book in order to enjoy the trivial intellectual tickling of the thing actually represented ; but the illustrations are of distinct educational value, in that they present aspects of things beautiful, or of matters desirable for practice, much more vividly than can be done by the unpictured text. I am indebted to the proprietors of The Garden for the use of some of the illustrations, and for a valuable list of plants and other particulars communicated to that journal by Mr. Correvon of Geneva ; also to the proprietors of Country Life for a still larger number of subjects for illustration ; to the late Mr. G. F. Wilson of Weybridge and former owner of the gardens at Wisley for several photographs for reproduction ; and to Mr. W. Robinson for two photographs of unusual interest. I have also to acknowledge the kind help of Mr. James Hudson, who compiled the list of Water-Lilies at the end of the last chapter. In some cases I have made critical observations PREFACE vii on pictures showing portions of various English gardens. If any apology is due to the owners of these gardens I freely offer it, though I venture to feel sure that they will perceive my intention to be not so much criticism of the place itself as the sug- gestion of alternatives of treatment such as might also be desirable in places presenting analogous conditions. G. J. CONTENTS CHAPTER I PAGE THE DRY-WALLED TERRACE GARDEN I CHAPTER II DRY-WALLING AND ROCK-GARDEN CONSTRUCTION . . IO CHAPTER III THE ROCK-WALL IN SUN l6 CHAPTER IV THE ROCK-WALL IN SHADE .28 CHAPTER V NATIVE PLANTS IN THE ROCK-WALL 36 CHAPTER VI TERRACE AND GARDEN WALLS 42 CHAPTER VII TERRACE AND GARDEN WALLS (continued} . . . 51 CHAPTER VIII SOME PROBLEMS IN WALL-GARDENING . . • • 59 CHAPTER IX WHEN TO LET WELL ALONE 63 ix x CONTENTS CHAPTER X PAGE THE STREAM-GARDEN AND MARSH POOLS .... 66 CHAPTER XI THE ROCK-GARDEN—GENERAL ARRANGEMENT 80 CHAPTER XII THE ROCK-GARDEN (continued} 90 CHAPTER XIII THE ALPINE GARDEN . . . . , . . . IOO CHAPTER XIV LAKES AND LARGE PONDS IOQ CHAPTER XV SMALL PONDS AND POOLS Ill CHAPTER XVI TUBS IN SMALL WATER OR BOG GARDENS . * . .128 CHAPTER XVII TANKS IN GARDEN DESIGN 135 CHAPTER XVIII A LILY TANK IN A FORMAL GARDEN . ». • * . 141 CHAPTER XIX WATER MARGINS >. • . . 154 CHAPTER XX WATER-LILIES. . . .... 160 LIST OF ILLUSTRATIONS A GARDEN OF WALL AND WATER .... Frontispiece CERASTIUM IN THE DRY WALL To face page i EASY STEPS WITH DRY- WALLING . . . . ,, ,, 2 ERINUS AND OTHER WALL PLANTS .... „ ,, 3 DWARF LAVENDER ,, ,, 4 ROSE AND PINKS IN THE DRY WALL . . . ,, ,, 5 ACHILLEA UMBELLATA ., 6 ACHILLEA UMBELLATA IN WINTER . . . . ,, ^ ICELAND POPPY ON THE DRY WALL . . . ,, 8 ARABIS IN A DRY WALL 9 DIAGRAM (SECTION) OF FACE OF ROCK-WALL . „ ., 10 ROCK- WALLING CONSTRUCTION ,. ., n ROCK-WALLING CONSTRUCTION ,, 12 ROUGH STEPS , ,. ,, 13 ROUGH STEPS IN A GRASS BANK . . . . ,, ,, 14 ERINUS IN ROUGH STEPS 15 ALPINE PLANTS IN SUNNY WALL .... ,, ,, 16 CERASTIUM IN A SUNNY WALL .... „ ,. 17 CAMPANULA GARGANICA „ ,, 18 CAMPANULA ISOPHYLLA ,, „ 19 IBERIS AND CERASTIUM ,, ,, 20 STONECROP IN A SUNNY WALL . . 21 LAVENDER-COTTON IN WINTER „ „ 22 DOUBLE ARABIS „ ,, 23 WAHLENBERGIA DALMATIC A ,, ,, 24 STOB^EA PURPUREA ,, ,, 24 A LARGE ROCK- WALL, WELL PLANTED . . . „ „ 24 CERASTIUM, PINKS, &c., IN DRY WALL . ,, ., 25 OUTER WALL, ALHAMBRA, GRANADA . . . ., ,, 26 FOLIAGE OF IRIS, &c., AT FOOT OF WALL . . ,, ., 26 SAPONARIA, &c., IN SUNNY WALL .... 26 xi xii LIST OF ILLUSTRATIONS SAXIFRAGA LONGIFOLIA, &c., IN SUNNY WALL . To face page 27 FERNS AT A NORTHERN WALL-FOOT ... „ „ 28 ANEMONE AND PRIMROSES AT WALL-FOOT . . „ ,, 30 WHITE ERINUS IN A SHADY WALL ... ,, ,, 31 RAMONDIA PYRENAICA . . . . , . „ ,, 32 SMILACINA BIFOLIA . ... . • . . „ ,, 33 CAMPANULA PUSILIA ,, „ 34 PRIMULA VISCOSA . . f , . . . „ „ 35 STITCHWORT IN A ROCK-WALL , , . , „ „ 36 CORYDALIS LUTEA . . , , , -. , . „ ,, 37 RED VALERIAN IN OLD CASTLE WALL . * . „ 39 CORYDALIS AND P'ERN IN OLD WALL . , , „ ,, 40 AN OLD MOAT WALL . . , . . , „ ,, 42 OLD MOAT WALL WITH INNER WALL . . . ,, ,, 43 A DOUBLE TERRACE . , . . . .",„,, 44 OLD GARDEN WALL ENCLOSING WILDERNESS . „ ,, 45 OLD OUTER GARDEN WALL . . . . * ,, ,, 46 AN OLD H.P. ROSE . . . . .*,„,, 47 RUBUS DELICIOSUS „ ,, 48 PEONY BORDER AND OLD BUILDINGS . . . „ 49 BOWLING-GREEN OF A TUDOR HOUSE . . . „ 50 A WELL-PLANTED WALL AND BORDER . . . ,, „ 51 TERRACED GARDEN ON STEEP SLOPE . . - < . „ ,, |j MIDDLE TERRACE, LOOKING EAST . . . „ „ 52 MIDDLE TERRACE, LOOKING WEST . . « , „ ,, 52 LOWER TERRACE . . . . . -"•;«• ,, ,, 53 CREEPERS ON A BEAUTIFUL OLD HOUSE . . „ 54 CAMPANULAS IN STONE STEPS . . , . . ,, „ 55 GARDEN STEPS OVERGROWN . . . . . ,, „•.-§§ TOADFLAX IN BRICK STEPS . . . . . ,, ., 56 GROUPING OF TREE AND WALL ... . „ „ 56 BRIDGE WITH WILD OVERGROWTH . . » . ,, „ 57 ARCHES, PESCINA ANAGNI, ITALY . . . „ „ 58 FLAGGED PASSAGE WITH PERGOLA . '•.. : * • „ ., 59 AN OLD WALL WITH OPEN JOINTS . . » „ „ 60 DIAGRAM: GROUPING OF WALL PLANTS . . . „ „ 61 BRICK WALL THAT COULD BE PLANTED . * . ,, ,, 62 LIST OF ILLUSTRATIONS xiii ARABIS, TYPE OF HANGING WALL PLANT . . To face page 63 A FINE HOUSE WITH UNBROKEN LAWN, &c. . „ „ 64 A WOOD POOL ,, „ 65 A STREAM GARDEN „ ,, 66 IRIS L^EVIGATA ,, „ 68 IRIS L/EVIGATA IN JAPAN ,, ., 69 WATER BUTTERCUP „ ,, 70 STREAM BY WILLOWS AND ALDERS .... „ ,, 71 CYPRIPEDIUM SPECTABILE 74 GALAX APHYLLA „ „ 75 XEROPHYLLUM ASPHODELOIDES ., ., 76 IN A FINE ROCK-GARDEN ,, „ 80 ZENOP.IA SPECIOSA „ ,, 81 STEPS IN ROCK-GARDEN ,, ,, 82 A VALLEY-SHAPED ROCK-GARDEN .... „ ,, 83 PATH IN ROCK-GARDEN ,, „ 84 ROCK-GARDEN CROWNED WITH SMALL SHRUBS . „ „ 85 MENZIESIA, THE IRISH HEATH .... ,, „ 86 PLAN OF THE ROCK-GARDEN „ „ 88 AUBRIETIA IN THE ROCK-GARDEN .... „ „ 90 LlTHOSPERMUM PROSTRATUM ,, ., 9! ARENARIA BALEARICA „ „ 92 LONDON PRIDE ., ,, 93 ANDROSACE LANUGINOSA „ .. 94 A WILD ROCK-GARDEN „ „ 94 DOUBLE SEA CAMPION ,, 94 HARDY RED-FLOWERED OPUNTIA .... ., 95 A BOLD ROCK-GARDEN, WELL PLANTED . . ., 96 BANK OF SPRING FLOWERS AT BATH . . . ., 96 RILL AND POOL IN ROCK-GARDEN ... ,, 96 IN MESSRS. BACKHOUSE'S ROCK-GARDEN . . ,, „ 97 WHITE HOOP-PETTICOAT NARCISSUS ... „ „ 98 TYPE OF THE SMALLER SILVERY SAXIFRAGES . „ „ 99 SAXIFRAGA LONGIFOLIA „ ,, 100 SAXIFRAGA BURSERIANA ,, ,, 101 GENTIANELLA „ ., 102 SlLENE ALPESTRIS „ „ 104 xiv LIST OF ILLUSTRATIONS SEMPERVIVUM LAGGERI . . , . . . To face page 106 A WILD WATER-GARDEN . .... . . „ „ 108 SCOTCH FIR ON LAKE SHORE », ,, 109 ROYAL FERN (OSMUNDA) • ,, s, no RIVER EDGE. RANUNCULUS FLORIBUNDUS, &c. . ,, ., 112 BUCKBEAN AND CHAIR-RUSH ., ,, 114 GUNNERA MANICATA „ ,, 115 NYMPH^EA ODORATA WITH BUCKBEAN, &c., AT MARGIN ,, ,, 116 RHODODENDRONS BY WATER ,, ,, 117 RHODODENDRONS AT A POND EDGE . . . ,, ., 118 POPLARS AND WATER VIOLET ,, ,, 119 STREAM AND POOL GARDEN, BY MESSRS. VEITCH OF EXETER. . ,, ,, 120 ROCK POOL, BY MESSRS. VEITCH OF EXETER . „ ,, 121 CASTLE MOAT WITH WILD GROWTHS . . . ,, ,, 123 ROCK AND POOL GARDEN ,, ,. 125 POOL AT THE VILLA D'ESTE . . . . . ,, ,, 126 THE SMALL WATER-LILY HELVOLA . . . ,, ,, 130 ROCK-BANK AND TANK IN BOG-GARDEN . . ,, ,, 132 ROUGH SEAT AND FLOWERS IN BOG-GARDEN . ,, ,, 133 GARDEN -TANK WITH FLAT KERB . . . . ,, ,, 135 GARDEN-TANK WITH SLIGHTLY RAISED KERB . ,, ,,136 POOL IN A BRICK- WALLED GARDEN COURT . . ,, „ 136 POOL IN A GARDEN COURT . . . , ' v „ ,, 136 DIAGRAM: POOL WITH DANGEROUS EDGE . . ,, ,, 137 COURT IN THE GENERALIFE GARDENS, GRANADA . „ ,, 138 POMPEII, ATRIUM AND PERISTYLIUM . , * „ ,, 139 FERN-CLAD ROCK- WALLS AT THE VILLA D'ESTE . ,, ,, 140 BALUSTRADED POOL IN AN ITALIAN GARDEN . ,, ,, 141 PLAN OF THE GARDEN DESCRIBED . < •/... . , . ,, ,, 149 STAIRWAY AT THE VILLA D'ESTE . , • ,, ,, 151 ARUMS AT A POND EDGE IN CORNWALL . , ,, ,, 154 GUNNERA MANICATA. , , • . . . . ,, ,, 156 IRIS I^EVIGATA IN THE ROYAL HORTICULTURAL SOCIETY'S GARDEN . . . . . . ,, ,, 156 COW-PARSNEP (HERACLEUM) . ... . ,, „ 157 LIST OF ILLUSTRATIONS xv A FLOWERY POND EDGE To face page 158 A POND THAT MIGHT BE IMPROVED ... „ ,, 159 A PLACE OF WILD WATER-LILIES . . . . ,, ,, 160 WATER-LILIES IN A SHELTERED POND . . . ,, ,, 161 WATER-LILIES ,, ,, 162 STEPPING-STONES ACROSS A LILY-POOL . . . ,, ,, 163 A LILY-POND ,,,,166 A LILY- POOL IN A ROCK-GARDEN . . . . ,, ,, 167 A CIRCULAR LILY-TANK . 168 CERASTIUM IN DRY- WALL. WALL AND WATER GARDENS .» C CHAPTER I THE DRY-WALLED TERRACE GARDEN MANY a garden has to be made on a hillside more or less steep. The conditions of such a site naturally suggest some form of terracing, and in connection with a house of modest size and kind, nothing is prettier or pleasanter than all the various ways of terraced treatment that may be practised with the help of dry-walling, that is to say, rough wall-building without mortar, especially where a suitable kind of stone can be had locally. It is well in sharply-sloping ground to keep the paths as nearly level as may be, whether they are in straight lines or whether they curve in following the natural contour of the ground. Many more beautiful garden-pictures may be made by variety in planting even quite straightly terraced spaces than at first appears possible, and the frequent flights of steps, always beautiful if easy and well proportioned, will be of the greatest value. When steps are built in this kind of rough terracing the almost invariable fault is that they are made too steep and too narrow in the A 2 WALL AND WATER GARDENS tread. It is a good rule to make the steps so easy that one can run up and down, whether they are of skilled workmanship, as in the present illustration, or rough, as in that at p. 14. There is no reason or excuse for the steep, ugly, and even dangerous steps one so often sees. Unless the paths come too close together on the upper and lower terraces, space for the more easy gradient can be cut away above, and the steps can also be carried out free below ; the ground cut through above being supported by dry-walling at the sides of the steps, and where the steps stand up clear below, their sides being built up free. If for any reason this is difficult or inexpedient, a landing can be built out and the steps carried down sideways instead of up and down the face of the hill. In fact, there is no end to the pretty and interesting ways of using such walling and such groups of steps. Where the stairway cuts through the bank and is lined on each side by the dry-walling, the whole structure becomes a garden of delightful small things. Little Ferns are planted in the joints on the shadier side as the wall goes up, and numbers of small Saxi- frages and Stonecrops, Pennywort and Erinus, Cory- dalis and Sandwort. Then there will be hanging sheets of Aubrietia and Rock Pinks, Iberis and Ceras- ttum, and many another pretty plant that will find a happy home in the cool shelter of the rocky joint. In some regions of the walling Wallflowers and Snap- dragons and plants of Thrift can be established ; as they ripen their seed it drifts into the openings of other joints, and the seedlings send their roots deep ERINUS, STQNECROPS AND TUFTS OF SILENE ACAULIS. DRY-WALLED TERRACE GARDEN 3 into the bank and along the cool backs of the stones, and make plants of surprising health and vigour that are longer lived than the softer-grown plants in the rich flower-borders. I doubt if there is any way in which a good quantity of plants, and of bushes of moderate size, can be so well seen and enjoyed as in one of these roughly terraced gardens, for one sees them up and down and in all sorts of ways, and one has a chance of seeing many lovely flowers clear against the sky, and of per- haps catching some sweetly-scented tiny thing like Dianthus fragrans at exactly nose-height and eye-level, and so of enjoying its tender beauty and powerful fragrance in a way that had never before been found possible. Then the beautiful detail of structure and marking in such plants as the silvery Saxifrages can never be so well seen as in a wall at the level of the eye or just above or below it ; and plain to see are all the pretty ways these small plants have of seating themselves on projections or nestling into hollows, or creeping over stony surface as does the Balearic Sandwort, or stand- ing like Erinus with its back pressed to the wall in an attitude of soldier-like bolt-uprightness. In place of all this easily attained prettiness how many gardens on sloping ground are disfigured by profitless and quite indefensible steep banks of mown grass ! Hardly anything can be so undesirable in a garden. Such banks are unbeautiful, troublesome to mow, and wasteful of spaces that might be full of interest. If there must be a sloping space, and if for 4 WALL AND WATER GARDENS any reason there cannot be a dry wall, it is better to plant the slope with low bushy or rambling things ; with creeping Cotoneaster or Japan Honeysuckle, with Ivies, or with such bushes as Savin, Pyrus japonica, Cistus, or Berberis ; or if it is on a large scale, with the free-growing rambling Roses and double-flowered Brambles. I name these things in preference to the rather over-done Periwinkle and St. John's-wort, because Periwinkle is troublesome to weed, and soon grows into undesirably tight masses, and the Hyperi- cum, though sometimes of good effect, is extremely monotonous in large* masses by itself, and is so ground-greedy that it allows of no companionship. There is another great advantage to be gained by the use of the terrace walls ; this is the display of the many shrubs as well as plants that will hang over and throw their flowering sprays all over the face of the wall. In arranging such gardens, I like to have only a very narrow border at the foot of each wall, to accommo- date such plants as the dwarf Lavender shown in the illustration, or any plant that is thankful for warmth or shelter. In many cases, or even most, it will be best to have no border at all, but to make a slight preparation at the wall foot not apparently distinguishable from the path itself, and to have only an occasional plant or group or tuft of Fern. Seeds will fall to this point, and the trailing and sheeting plants will clothe the wall foot and path edge, and the whole thing will look much better than if it had a stiffly edged border. I suppose the whole width of the terrace to be four- AN OLD GARDEN ROSE AND HYBRID ROCK PINKS IN THE DRY- WALL. DRY-WALLED TERRACE GARDEN 5 teen feet. I would have the path six feet wide, allow- ing an extra foot for the rooting of plants next the wall ; then there would be a seven-foot width for the border, planted with bushy things towards its outer edge, which will be the top of the wall of the next terrace below. These would be mostly bushes of moderate growth, such as Lavender, Rosemary, Ber- beris, and Pyrus japonica, with the plants suitable for partly hanging over the face of the wall. Among these would be Forsythia suspensa, Phlomis fruticosa (Jeru- salem Sage), and the common Barberry, so beautiful with its coral-like masses of fruit in October, its half- weeping habit of growth, and its way of disposing its branches in pictorial masses. There would also be Des- modium penduliflorum, and above all the many kinds of Roses that grow and flower so kindly in such a posi- tion. No one can know till they try how well many sorts of Roses will tumble over walls and flower in profusion. Rosa lucida and Scotch Briers come over a wall nearly five feet high, and flower within a foot from the ground ; Rosa wichuraiana hangs over in a curtain of delicate white bloom and polished leafage. There is a neat and pretty evergreen form of R. sem- pervirens from Southern Italy, in leaf and habit not unlike wichuraiana^ but always more shy of flower, which hangs over in masses, and in warm exposures flowers more freely than on the flat. If one had to clothe the face of a wall twelve feet high with hanging wreathes of flowering Roses, there is a garden form of R. arvensis that, planted at the top, will climb and scramble either up or down, and will ramble through 6 WALL AND WATER GARDENS other bushes to almost any extent. I know it as the Kitchen Rose, because the oldest plant I have rambles over and through some Arbvr-vitce just opposite the kitchen window of a little cottage that I lived in for two years. When it is in flower the mass of white bloom throws a distinctly appreciable light into the kitchen. The Ayrshire Roses are delightful things for this kind of use. Where in steep ground the terraces come near to- gether the scheme may comprise some heroic doings with plants of monumental aspect, for at the outer edge of one of the wall tops there may be a great group of Yucca gloriosa or F. recurva, some of it actually planted in the wall within a course or two of the top, or some top stones may be left out ; or the Yuccas may be planted as the wall goes up, with small kinds such as F. flaccida a little lower down- Another such group, of different shape but clearly in relation to it, may be in the next terrace above or below. When the Yuccas are in flower and are seen from below, complete in their splendid dignity of solid leaf and immense spire of ivory bloom, against the often cloudless blue of our summer skies, their owner will rejoice in possessing a picture of per- haps the highest degree of nobility of plant form that may be seen in an English garden. The garden of dry-walled terraces will necessarily be differently treated if its exposure is to the full southern or south-western sunshine, or to the north or north-east. In the case of the hot, dry, sunny aspect, a large proportion of the South European ACHILLEA UMBELLATA NINE MONTHS AFTER PLANTING. ACHILLEA UMBELLATA IN MID-WINTER, SIXTEEN MONTHS AFTER PLANTING, (Half of the same group that is shown at p. 6, scale rather larger.) DRY-WALLED TERRACE GARDEN 7 plants that are hardy in England and like warm places in our gardens, can be used. Many of these have greyish foliage, and it would be greatly to the advantage of the planting, from the pictorial point of view, to keep them rather near together. It should also be noted that a large proportion of them, of shrubby and half-shrubby character, are good winter plants, such as Lavender, Rosemary, Phlomis, Othon- nopsis, and Santolina; the last, as may be seen in the illustration at p. 22, being specially well clothed in the winter months. They can be as well planted at the top edge of the wall, at the bottom, or in the face. With these plants well grouped, and the addition of some common white Pinks, and the useful hybrids of Rock Pinks ; with a few grey-leaved Alpines such as Cerastium, Artemisia nana, A. sericea, the encrusted Saxifrages, and Achillea umbellata, a piece of the best possible wall-gardening can be done that will be as complete and well furnished in winter (but for the bloom of the plants) as it is in summer. Achillea umbellata is a plant of extreme value in wall-planting in all aspects It grows fairly fast, and from a few pieces of a pulled-apart plant will in a short time give the result shown in the illustrations ; it should be replanted every three years. There is no need in such a case to remember the exact date of planting. The plant is at its best in its first and second year ; then it begins to look a little straggly and over-worn. This may be taken as the signal for replanting, as in all such cases with any other plants. Such a choice of plants would serve for quite 8 WALL AND WATER GARDENS a long section of wall. The character of the planting might then change and gradually give way to another grouping that might be mainly of Cistuses. With these, and in the hottest wall-spaces, might come some of the South European Campanulas; C. iso- phylla, both blue and white, C. garganica, C. fragilisj and C. muralis. These gems of their kind live and do well in upright walling, whereas they would perish on the more open rockery, or could only be kept alive by some unbeautiful device for a winter pro- tection. Not only does the wall afford the shelter needed for plants that would otherwise be scarcely hardy, but the fact of planting them with the roots spread horizontally, and the crown of the plant therefore more or less upright instead of flat, obviates the danger that besets so many tender plants, of an accumulation of wet settling in the crown, then freezing and causing the plant to decay. In many places where these rather tender southern plants are grown, they require a covering of sheets of glass in the winter, whereas in the wall they are safe and have no need of these unsightly con- trivances. SOME OF THE PLANTS AND SHRUBS FOR DRY-WALLED TERRACES IN A COOL PLACE Saxifrages, Mossy. Corydalis. Wall Pennywort. Erinus alpinus (cool or warm). Arenaria balearica. Small Ferns. ICELAND POPPY AT THE TOP OF THE ROCK-WALL ARAB IS IN A DRY -WALL. DRY-WALLED TERRACE GARDEN 9 To HANG DOWN Rock Pinks. Aubrietia. Iberis. Cerastium. Alyssum. Mossy Saxifrage (cool). Othonnopsis. Arabis and double var. IN SUN OR SHADE Wallflowers. Thrift. Snapdragons. Dianthus fragrans. Centranthus. SHRUBS TO HANG OVER FROM THE TOP Cistus cyprius. Phlomis fruticosa. C. laurifolius. Santolina chamacyparissus. Lavender. Rosemary. Othonnopsis cheirifolia. Berberis vulgaris. Desmodium penduliflorum. Pyrus japonica. Rosa lucida. Rosa ivichuraiana. R. sempervirenS) vars. R. arvense, garden vars. GREY-LEAVED ALPINE PLANTS FOR THE WALL Cerastium tomentosum. Achillea umbellata. Artemisia nana. Artemisia sericea. PLANTS FOR HOTTEST PLACES Campanula isophylla. Campanula garganica. C.fragilis. C. muralis. Yucca gloriosa. Yucca recurva. Y. flaccida. Opuntia, in var. Stonecrops. CHAPTER II DRY-WALLING AND ROCK-GARDEN CONSTRUCTION A ROCK-GARDEN may be anything between an upright wall and a nearly dead level. It is generally an arti- ficial structure of earth and stones, and alas ! only too often it is an aggregation of shapeless mounds and hollows made anyhow. Such a place is not only ugly but is very likely not suitable for the plants that are intended to grow in it. If any success in the cultivation of rock-plants is expected, it is only reasonable to suppose that one must take the trouble to learn something about the plants, their kinds and their needs, and it is equally necessary to take the trouble to learn how their places are to be prepared. Happily for the chances of success and pleasure in this delightful kind of gardening the right way is also the most beautiful way. There is no need to sur- round every little plant with a kind of enclosure of stones, set on edge and pointing to all four points of the compass ; it is far better to set the stones more or less in courses or in lines of stratification, just as we see them in nature in a stone quarry or any moun- tain side where surface denudation has left them standing out clear in nearly parallel lines. It matters not the least whether the courses are far apart or DIAGRAM (SECTION) SHOWING ALTERNATIVE ARRANGEMENT OF THE FACE OF THE STONES IN A ROCK-WALL AT AN ANGLE OF 45°. (Seep, u.) ROCK-GARDEN CONSTRUCTION n near together; this is naturally settled by the steep- ness of the ground. In a wall they are necessarily close, and in very steep ground it is convenient to build them with the courses rather near each other. In such a case as a steep slope with an angle of 45 degrees, the face of the rock-bank could be built in either of the two ways shown in the diagram. Both will suit the plants. The flatter the angle of the ground the further apart may be the rocky courses, as the danger of the earth washing away is diminished. If the stone is not in large pieces, it will be found a good plan in rather steep banks to begin at the path level with a few courses of dry-walling, and then to make an earthy shelf and then another rise of two or three courses of walling, using the two or three courses to represent one thickness of deeper stone. But in any case the rock-builder should make up his mind how the courses should run and keep to the same rule throughout, whether the stones lie level or dip a little to right or left as they generally do in nature. But whether a stone lies level or not as to the right and left of its front face, it should always be laid so that its back end tips down into the ground, and its front face, when seen in profile, looks a little upward. This, it will be seen, carries the rain into the ground instead of shooting it off as it would do if it were laid the other way, like the tile or slate on a building. As for the general shape or plan of the rock-garden, it must be governed by the nature of the ground and the means and material at disposal. But whether it 12 WALL AND WATER GARDENS will be beautiful or not as a structure must depend on the knowledge and good taste of the person who plans it and sees it carried out. As mentioned elsewhere, it is both highly desirable and extremely convenient to have different sections of the garden for the plants from different geological formations, therefore we will suppose that a portion is of limestone, and another of granite, and a third of sandstone with peat. If this sandstone and peat is mainly in the shadiest and coolest place, and can have a damp portion of a few square yards at its foot, it will be all the better. Of course if a pool can be managed, or the rock-garden can be on one or both banks of a little stream or rill, the possibilities of beautiful gardening will be endless. In making the dry-walling the stones should all tip a little downwards at the back, and the whole face of the wall should incline slightly backward, so that no drop of rain is lost, but all runs into the joints. Any loose earth at the back of the stones must be closely rammed. If this is done there is no danger of the wall bursting outward and coming down when there is heavy rain. Any space backward of newly moved earth behind the wall must also be rammed and made firm in the same way. The two illustrations of a bit of dry wall freshly put up give an idea of the way it is built. The one containing the angle shows how the stones are tipped back, while the one with the straight front shows how spaces at some of the joints and between the courses are left for planting. If the scheme of planting is 'O ROCK-GARDEN CONSTRUCTION 13 matured and everything at hand as the wall goes up, it is much best to plant as the stones are laid. The roots can then be laid well out, and larger plants can be used than if they were to be put in when the wall is completed. In making the steps that go with such dry-walling it will not be necessary that they should be entirely paved with stones. If the front edge is carefully fitted and fixed the rest can be levelled up with earth and the sides and angles planted with bits of Mossy Saxi- frages or other small growths. This is also a capital way of making steps in steep wood paths. In such places the use of thick wooden slab as an edging is a much worse expedient, for in wet or wintry weather it becomes extremely slippery and dangerous. The steps themselves will become flower gardens ; only the front edges need be cemented ; indeed, if the stones are large and heavy enough to be quite firm there need be no cement ; but if two or three stones are used to form the edge of a four-foot-wide step it is just as well to make a cement joint to fix the whole firmly together. This fixing need not be made to show as a conspicuous artificial joint ; it can be kept well down between the stones, and spaces left above and below to form many a little nook where a tiny Fern may be planted, or a little tuft of some other small plant — any plant that one may most wish to see there. If the space is cool and shady the little Saxifraga Cymbalaria is a charming thing. It is an annual, but always grows again self-sown ; in the depth of winter its cheerful tufts of little bluntly-lobed i4 WALL AND WATER GARDENS leaves look fresh and pretty in the joints of stones. It flowers quite early in the year and then withers away completely, but the seeds sow themselves, and so without any one taking thought or trouble it renews itself faithfully from year to year. Many small Ferns will also be quite happy in the front joints of the shady steps, such as Cheilanthes vestita, Cystopteris fragilis and C. dickieana, Asplenium Trichomanes, A. Ruta-muraria, Ceterach, and the Woodsias. The little creeping Arenaria balearica will grow up the cool side of the wall or the front edge of steps and be a carpet of vivid green in deepest winter, and in June will show a galaxy of little white stars on inch- long thread-like stalks that shiver in the prettiest way to the puffing of a breath of wind or the weight of raindrops of a summer shower. In a couple of years or even less, small Mosses will appear on the stones themselves, and the spores of Ferns wind-blown will settle in the stony face and in the joints ; then will come the delight of seeing these lovely things growing spontaneously, and coming willingly to live in the homes we have made ready for them. No little flowering plant seems more willing to take to such a place than Erinus alpinus. As soon as steps grow mossy (even if they are of solid bricklayer's work with mortar joints), if a few seeds of Erinus are sown in the mossy tufts they will gladly grow as shown in the illustration, where this cheerful little plant has been established on some solid steps of rough sand- stone leading to a loft, and now scatters its own seed STEPS IN A ROUGH GRASS BANK; STONES CEMENTED AT FRONT. 2, 8 ROCK-GARDEN CONSTRUCTION 15 and is quite at home as a well-settled colony making natural increase. This is an extreme case, for the little Alpine has nothing whatever to grow in but the mossy tufts that have gathered of themselves within the time, some eight years, since the steps were built. Had the steps been of dry-walling, such as was described in the early part of the chapter, they would have grown all the quicker, having the more favour- able conditions of a better root-run. CHAPTER III THE ROCK-WALL IN SUN MANY of the most easily grown Alpines are just as happy in a sunny wall as in the shade. So bene- ficent to the roots is contact with the cool stone, that plants that would perish from drought in the lighter soils and fierce sun-heat of our southern counties remain fresh and well nourished in a rock-wall in the hottest exposure. Moreover, in walls all plants seem to be longer lived. Those of the truly saxatile plants, whose way of growth is to droop over rocks and spread out flowering sheets, are never so happy as in a rock-wall. But it cannot be too often re- peated that to get good effects a few kinds only should be used at a time. So only can we enjoy the full beauty of the plant and see what it really can do for us ; so only can we judge of what the plant really is, and get to know its ways. In many of those rock-plants that are grown from seed, indi- viduals will be found to vary, not only in the colour and size of the bloom, but in other characters, so that the plant cannot be judged by one example only. Look at the variety in trees — in Birches, in Hollies, in Oaks ! Still more is this natural variation notice- able in small plants that are close to the eye. In 16 ALPINE PLANTS IN A SUNNY LIMESTONE WALL AT THE JARDIN ALPINE D'ACCLIMATATION , GENEVA. SAXIFRAGA LONGIFOLIA ERINUS, PHYTEUM A COMOSUM, ETC. (For Saxifniga • Ion gi folia in Flower see p. 100.) CHAPTER III THE ROCK-WALL IN SUN MANY of the most easily grown Alpines are just as happy in a sunny wall as in the shade. So bene- ficent to the roots is contact with the cool stone, that plants that would perish from drought in the lighter soils and fierce sun-heat of our southern counties remain fresh and well nourished in a rock-wall in the hottest exposure. Moreover, in walls all plants seem to be longer lived. Those of the truly saxatile plants, whose way of growth is to droop over rocks and spread out flowering sheets, are never so happy as in a rock-wall. But it cannot be too often re- peated that to get good effects a few kinds only should be used at a time. So only can we enjoy the full beauty of the plant and see what it really can do for us ; so only can we judge of what the plant really is, and get to know its ways. In many of those rock-plants that are grown from seed, indi- viduals will be found to vary, not only in the colour and size of the bloom, but in other characters, so that the plant cannot be judged by one example only. Look at the variety in trees — in Birches, in Hollies, in Oaks ! Still more is this natural variation notice- able in small plants that are close to the eye. In 16 ALPINE PLANTS IN A SUNNY LIMESTONE WALL AT THE JARDIN ALPINE D'ACCLIMATATION , GENEVA. SAXIFRAGA LONGIFOLIA ERIN US, PHYTEUM A COMOSUM, ETC. (For Saxifyaga • Ion gi folia in Flower see p. 100.) THE ROCK-WALL IN SUN 17 watching a number of the same kind one learns how to judge them; one sees in Cerastium, for instance, such as one of the many tufts hanging out of the wall in the picture, that one tuft has a brighter and better appearance than the next one. Then one sees that the flower, which at first one had thought was whiter than its neighbour, is not different in colour, but has rather wider petals, and that they open more and lie a little flatter, and that the leaf is somewhat broader and its downy covering slightly heavier and therefore whiter looking. Nothing is a better lesson in the knowledge of plants than to sit down in front of them, and handle them and look them over just as carefully as possible ; and in no way can such study be more pleasantly or conveniently carried on than by taking a light seat to the rock- wall and giving plenty of time to each kind of little plant, examining it closely and asking oneself, and it, why this and why that. Especially if the first glance shows two tufts, one with a better appearance than the other ; not to stir from the place until one has found out why and how it is done, and all about it. Of course a friend who has already gone through it all can help on the lesson more quickly, but I doubt whether it is not best to do it all for oneself. Then the hanging plants, Cerastium, Afyssum, Aub- rietia, Silene, Arabis, Gypsophila, Saponaria, Rock Pinks and the like, though they grow quite happily on the level, do not show their true habit as they do when they are given the nearly upright wall out of which they can hang. There are plenty of plants for the B i8 WALL AND WATER GARDENS level, and this way of growing in hanging sheets is in itself a very interesting characteristic, point- ing to the use of many beautiful things in circum- stances that could not otherwise be dealt with so satisfactorily. The Rock Pinks and their hybrids are very im- portant wall-plants of the hanging class. The hy- brids for such use are derived from Dianthus ccesius (the Cheddar Pink), D. plumarius, D. superbus, D. fragrans, and possibly others. D. fragrans and its double variety are delightful wall-plants; the double is that wonderful tiny white Pink whose scent is like the quintessence of that of Jasmine ; a scent almost too powerful. Seed of these hybrids can be had by the name of Hybrid Rock Pinks ; it is easily grown and yields interesting varieties, all capital wall and rock plants. The Rock Pinks are equally happy in a wall in sun or shade ; but as we are just now considering the plants that will bear the hottest places, among the most important, and at the same time the most beautiful, will be some of the tender Campanulas of Southern Italy, and others that are usually found tender or difficult of culture in England. Campanula garganica, a native of rocks and walls in that curious promontory of Gargano that stands out into the Adriatic (the spur on the heel of Italy), is often an uncertain plant in our gardens. But planted in a cleft in very steep, almost wall-like rock-work, or still better in an actual wall in the hottest exposure, where it cannot surfer from the moisture that is THE ROCK-WALL IN SUN 19 so commonly fatal to it, it will thrive and flower abundantly. This species, with other Campanulas that are absolutely saxatile, should in England always be grown in a wall or perpendicular rock-work. The same treatment suits C. Raineri, the yellow-flowered C. petraa of the Tyrol, and Campanulas muralis, Elatine, elatinoides, excisa, macrorhiza, and mirabilis. That the same plan is suitable to C. isophylla may be seen by the illustration showing a tuft flowering in a wall facing south-west, in a garden thirty-five miles south-west of London. Places should also be given to the tenderer of the Lithospermums, L. Gastoni and L. graminifolium. Graminifolium is a neat bushy-looking plant ; both have the flowers of the fine blue colour that is so good a character of the genus. In hottest exposures in Devon and Cornwall and the Isle of Wight there would even be a chance of success with L. rosmarini- folium, the " Blue Flower" of the Island of Capri. Its colour may be said to be the loveliest blue in nature. It has not the violent intensity of the Gen- tian, but a quality entirely its own. If one may without exaggeration speak of a blue that gives the eye perfect happiness, it would be this most perfect blue of the lovely Gromwell of the cliffs of Capri. But it must have sun and air and full exposure, or the colour is wanting in quality, therefore it is not a plant for the unheated greenhouse. The easily grown Z. prostratum likes a rather cooler place, and is more a plant for the rock-garden or for 20 WALL AND WATER GARDENS grassy banks. This most useful trailer is not par- ticular about soil, though the Lithospermums as a genus are lime-loving things. Another important race of plants for the hot wall are the various kinds of Ibens. All will do well. The commonest perennial kind, /. sempervirens, shows new beauties in the wall. Still better is the hand- somer /. correafolia, larger both of leaf and flower. In the south of England we may also have /. gib- raltarica and /. tenoreanay both white, tinted with pink or lilac, and /. Pruiti, pure white, all South European plants. These are short-lived perennials, scarcely more than biennials, but they come well from seed which should be sown in the wall ; the unmoved seedlings will do ' much better than any transplanted ones. Closely allied to the Iberises and capital wall-plants, doing well in all soils, but preferring lime, are the ^thionemas, mostly small neat plants with bluish leaves and pretty pink flowers. ./££. coridifolium or pukhellum, from Asia Minor, is charming against grey stones, while the Syrian ;E. grandiflorum is like a beautiful little pink-flowered bush. Rabbits are very fond of this family of plants, indeed they seem to favour the Crucifer ^ ;£ u •S JJ3 ^ « - 8,5-8 rt § ^-^ •« S«tf J ril*>]>«?1 ^s2a4lp*§»i! fijt^Bin -•^rt^rH^S^nc;^ ,^-5^ gj l^° S° it VE'iKJli-lt w.S^^^^g.-g^O I?e5^r«.!!^x'*e S S gW^J rtf^^pq g ^ •gig "§1 I || rt^B rtw K ^G ftuJ Etaf fill ;(Si2i5 1 & z Ul 0 tt THE ROCK-GARDEN 89 SOME OF THE EASIEST GROWN ROCK-GARDEN PLANTS. Accena microphylla, pulchella. Achillea umbellata. Adonis vernalis. dLthionema grandiflorum. Ajuga, vars. Alchemilla alpina. Alyssum saxatile. Anemone blanda, nemorosa, vars., sylvestriS) apennina. Anthericum Liliastrum, Liliago. Antennaria dioica, tomentosa. Antirrhinum glutinosum, Arabis albida^ and double var. Arenaria balearica^ montana. Armeria vulgaris^ Cephalotes. Artemisia sericea. Asarum europceum. Aster alpinus. Attbrietia deltoides^ grceca. Campanula pulla^ ccespitosa^ carpatica^ pusilla^ barbata. Cardamine pratensis fl. pl.^ tri- folia. Cerastium tomentosum. Coptis trifolia. Cheiranthus alpinus^ Mar- shalli. Cory if alts bulbosa, capnoides. Delphinium nudicaule. Dentaria diphylla. Dianthus ctzsius, deltoides^ fra- gransy and vars. Draba aizoides. Epimedium macranthum. Erica, vars. Erinus alpinus. Gentiana acaulis, asclepiadea. Helianthemum, vars. Hemerocallis Dumortieri. Hieracium aurantiacum^ mllo* sum. Hutchinsia alpina. Iberis sempervirens. Iris cristata^ pumila, vars. Linaria alpina^ pallida, hepati- cczfolia. Linum ftavum. Lithospermum prostratum. Lychnis alpina. Mentha Requieni. Mimulus cupreus. Nierembergia rivularis. Orobus vernus, aurantius. Papaver alpinum. Phlox setacea^ vars. Polygala Chamcebuxus. Polygonum affine^ vaccini- folium. Potentilla alchemilloides dubia. Primula rosea^ denticulata% sikkimensis. Sanguinaria canadensis. Saponaria ocymoides. Saxifraga, Semperuivum^ and Sedum, many sps. Silene alpestris. Thymus lanuginosus^ Strpyl- lum albus. Tiarella cordifolia. Uvularia grandiftora. Vesicaria utriculata. CHAPTER XII THE ROCK-GARDEN (continued) IT can never be repeated too often that in this, as in all kinds of gardening where some kind of beauty is aimed at, the very best effects are made by the sim- plest means, and by the use of a few different kinds of plants only at a time. A confused and crowded com- position is a fault in any picture ; in the pictures that we paint with living plants just as much as in those that are drawn and painted on paper or canvas. Moreover, the jumbled crowd of incongruous items, placed without thought of their effect on one another, can only make a piece of chance patchwork ; it can never make a design. However interesting the indi- vidual plants may be, we want to get good proportion and beautiful combination in order to make the good garden-picture, while the individuals themselves gain in importance by being shown at their best. I have therefore thought it would be helpful to put together lists of plants for the different situations, and within the lists to bracket the names of some that look the best as near neighbours. In many cases they can be intergrouped at the edges. These lists appear at the end of the chapter. Where the same plant is named more than once, it is to be understood that it is good AUBRIETIA IN THE ROCK-GARDEN. LITHOSPERMUM PROSTRATUM (BRIGHT BLUE) HANGING OVER ROCK ; A SILVERY SAXIFRAGE BELOW. THE ROCK-GARDEN 91 to use in more than one combination. A few examples of such groupings of plants will be described, and others given in the lists. When I think of the rock-garden plants, and try to bring to mind those that have given me most pleasure for a fair length of time, I think the roll of honour must begin with Lithospermum prostratum. There are many that give one as keen a feeling of delight and thankfulness for a week or ten days, or even a little more ; but for steady continuance of beautiful bloom I can think of nothing so full of merit. It is, there- fore, the best of plants for any important rocky knoll, and, as its habit is to trail downwards, it may well go on the very top of some jutting promontory fairly to the front, or be at the top of a bit of almost wall-like rock-work as in the picture. It is neat-looking all the year through, and the deep colour of the small rough leaves sets off the strong pure blue of the flowers. In winter the leaves turn to a kind of black bronze, but never lose their neat appearance, as of a well-fitting ground carpet. The colour blue in the garden, as also in other fields of decorative practice, seems to demand a treatment by contrast as an exception to the generally desirable rule of treatment by harmony. Therefore I do not hesitate to plant near the Lithospermum the brilliant pale yellow Cheiranthus alpinus, and, though I do not find use for many plants with variegated foliage, I like to have in the same group the pretty little Arabis lucida variegata. Among a host of plants that are of so eminent a degree of merit that it is almost impossible to give 92 WALL AND WATER GARDENS precedence to any one, Achillea umbellata takes high rank. The two illustrations in the chapter on the Sunny Rock-wall (pp. 6 and 7) show it both in summer bloom and winter foliage. With this charming thing I should group some of the plants of low-toned pink blossom, such as Thrift and the pink-flowered Cudweed (Antennaria), and any of the encrusted Saxifrages ; or separately with the charming Phlox setacea " Vivid," in this case with nothing else then in bloom quite near. There are some little plants that grow in sheets, whose bloom is charming, but on so small a scale that other flowers of larger size or stouter build would seem to crush them. Such a one is the dainty little Linnaea, which should have a cool shady region of its own among tiny Ferns, and nothing large to over- master it. The little creeping Linaria hepaticcefolia is another of this small, dainty class, best accompanied by things of a like stature, such as Arenaria balearica, and per- haps little Ferns and Mossy Saxifrages. Arenaria balearica is a little gem for any cool rocky place ; it grows fast and clings close to the stones. It always spreads outwardly, seeking fresh pasture ; after a time dying away in the middle. The illustration having this Arenaria on the angle of a small rock-garden shows a little dark patch on its surface, first flowerless and then dying away, while the outer fringe of the patch grows onward. Aubrietia> Arabis, Iberis, and Cerastium, four of the commonest of spring-blooming plants of Alpine origin that have long been grown in LONDON PRIDE (SAX IF RAG A UMBROSA] ; TYPE OF ONE IMPORTANT CLASS OF SAXIFRAGE. THE ROCK-GARDEN 93 gardens, are capital companions, making sheets of hanging or trailing bloom at that flowery time when spring joins hands with summer. The palest coloured of the Aubrietias, such as the variety " Moorheimi," are among the best, and should not be neglected in favour of the stronger purples only. A little later in the year Campanula pulla and Silene alpestris do well together, plentifully framed with small Ferns and Mossy Saxifrages. The lovely Iris cristata is charming with Corydalis capnoides of the pale yellowish white bloom and bluish almost feathery leaves. In the upper and bolder regions of the rock- garden where there will be small shrubs, the fine blue-flowered dwarf Flag Iris, /. Cengialti, should be grouped under a bush of Eurybia gunniana. London Pride, the best of the Saxifrages of that class, should be plentifully grouped with strong patches of the lovely white St. Bruno's Lily, backed by some bushes of dark foliage as of Gaultheria Shallon or Alpine Rhododendron. It is one of the pleasures of the rock-garden to observe what plants (blooming at the same time) will serve to make these pretty mixtures, and to see how to group and arrange them (always preferably in long-shaped drifts) in such a way that they will best display their own and each other's beauty ; so that a journey through the garden, while it presents a well-balanced and dignified harmony throughout its main features and masses; may yet at every few steps show a succession of charming lesser pictures. 94 WALL AND WATER GARDENS It is only possible to point to a few examples, but those who work carefully in their rock-gardens will see the great gain that rewards a little care and thought in putting the right things together. If they will take the trouble to work out the few examples given, they will be able to invent many other such combinations for themselves. Then there comes the question of putting the right plants in the right places. The picture of Androsace lanuginosa may be taken as an illustration of a good rock-plant well placed, partly on the flat, but also falling down the face of the rock. Nothing but a knowledge of the plant's ways and a lively sympathy with its wants can make right placing a certainty, but the gradual learning of these things is one of the pleasures of gardening. Where the garden adjoins ground of a rocky, or rocky and woody character, the difficulty of con- struction is reduced to the lowest point. There are thousands of acres of such ground in the remoter parts of our islands, many of them no doubt so placed that with a very little alteration and the addition of just the right plants, the most beautiful of rock- gardens could be made. Such ground as the rocky wood with its own wild Foxgloves shown in the illustration could hardly be bettered as a rock-garden background, and would suggest bold treatment, in- deed would absolutely forbid anything petty or niggling. It is highly interesting to have a space in one of the warmest and most sheltered regions of the rock- HARDY RED-FLOWERED OPUNTIA (0. XANTHOSTEMA) IN STEEP ROCK-WORK. THE ROCK-GARDEN 95 garden for the hardy Opuntias. They are the more desirable in that they are not only the sole repre- sentatives of the large Cactus family that are hardy in England, but that they are also desirable flowering plants, of large bloom and moderate habit of growth. The family comprises so many species of monstrously ungainly or otherwise unsightly form that it is for- tunate for our gardens that the hardy species should be beautiful things. Opuntia Raffinesquii has long been with us, and more lately we have had the good yellow-bloomed species 0. camanchica, arenaria, fragilis, and Engel- mannL To these with yellow flowers have been added still later O. rhodanthe and O. xanthostema. They are all North American plants, most of them natives of Colorado. They like a place among steep rocks in a soil of poor sand and broken limestone, in the hottest exposure. The only thing they dislike in our climate is long-continued rain, from which the steep rock-wall in a great measure protects them, by means of the complete drainage that it secures. We have a fine example of good rock-gardening accessible to the public in the Royal Gardens, Kew. Here there is not only a copious collection of moun- tain plants of the kinds suitable for rock-gardens and their immediate neighbourhood, but we see them as well arranged as is possible in an establishment that, it must be remembered, is primarily botanical ; indeed the way in which the gardens have been of late years enriched with large breadths of bulbous plants in 96 WALL AND WATER GARDENS grass and beautiful flowering shrubs, not in single specimens only, but in bold groups, has been a power- ful means of instruction, and has done as much as anything to help people to know the good plants and how best to use them. There is a beautiful rock-garden in the grounds of Messrs. Backhouse of York, a firm well known for their admirable collection of Alpine plants. It is most instructive to see in this fine garden some of the difficult Alpine plants looking perfectly at home. The growth of interest in rock-plants has neces- sarily given an immense impetus to horticultural trade and allied crafts, for there are other good firms that make a specialty of constructing rock- gardens, while the success that is attained may be seen by the illustrations. Indeed, rock-gardens and Alpine gardens great and small, carefully made and intelligently planted, may now be seen throughout the country. In planting the rock-garden it is a good plan to allot fairly long stretches of space to nearly related and nearly allied plants, especially to those genera that contain many desirable species and varieties. Several genera will be largely represented ; of these the principal are Saxifraga, Sedum, Sempervivum, Cam panula, Silene, Linaria, Iberis, Iris, Draba, Dianthus, and Primula. This way of grouping, if well arranged with some intergrouping of smaller plants, will not only have the best effect but will have a distinct botanical interest ; not botanical in the drier sense of mere classification, but botanical as a living exposition A BANK OF SPRING-FLOWERING ALPINE PLANTS (ARABIS, AUBRIETIA, ETC.] IN THE BOTANIC GARDEN, BATH. MESSRS. BACKHOUSE'S ROCK GARDEN AT YORK. THE ROCK-GARDEN 97 of variation of form within the law of a common structure. Besides the grouping in families, the following list contains, bracketed together, names of plants that have a good effect when grouped near each other : — f Lithospermum prostratum. \ Cheiranthus alpinus. [ Arabis lucida variegata. A chillea umbellata. Antennaria tomentosa. Armeria vulgaris. A. Cephalotes. Saxifraga (encrusted vars.). f Linaria hepatictzfolia. J L.pallida. [ Small Ferns. ? Cardaminepratensisfl.pl. J Arenaria balearica. (^ Mossy Saxifrage. / Aubrietia grceca, &c. J Arabis albida. | Iberis sempervirens. \ Cerastium tomentosum. f Iberis correcefolia. J Phacelia campa?iularia(sQVfn). [ Mossy Saxifrage. j Cornus canadensis. \ Waldsteineafragarioides. ( Adonis vernalis. \ Tulipa sylvestris. C Ttinica Saxifraga. -! Saponaria ocymoides. \^Dianthus deltoides. f Vesiaria utriculata. \ Cheiranthus mutabilis. i Silene alpestris. \ Campanula pulla. ( Saxifraga umbrosa. \ Anthericum liliastrum. ( Silene maritimafl.pl. \ Othonnopsis cheirifolia. ( Iris cristata. ( Corydalis capnoides. Tiarella cordifolia. Myosotis dissitiflora major. ^ Mertensia virginica. Ramondia pyrenaica. Haberlea rhodopensis. . Cystopterisfragilis. ( Dianthus alpinus. -j Cardamine trifoliata. \ Hutchinsia alpina. l A chillea Clavenna. \ Scabiosa Pterocephala. Anemone blanda. Galanthus E live si. ( Iris reticulata. \ Mossy Saxifrage. C Orobus vermis. ( Aubrietia grcEca. ( Veronica satureifolia. \ Silene alpestris. ( Anemone apennina. \ Trillium grandiflorum. \ Omphalodes verna. 98 WALL AND WATER GARDENS SOME BULBOUS PLANTS FOR THE ROCK-GARDEN Acts autumnalis. Triteleia uniflora. Crocus species. Narcissus minor. N. minimus. N. Bulbocodium N. B. citrinus. N. juncifolius. N. odorus minor. N. poeticus verb anus. N. triandrus. Leucojum -vernum. Galanthus Elwesii. Fritillaria armena. F. aurea. F. pudica. F. Meleagris. Oxalis enneaphylla. Cyclamen Atkinsii and vars. C. Coum. C. repandum. C. europcBum. Anomatheca cruenta. Chionodoxa Lucilia. C. sardensis. Dodecatheon, vars. Puschkinia libanotica. Corydalis bulbosa. C. bracteata. Sternbergia lutea. Tecophilcea cyanocrocus. Eucomis punctata. Scilla sibirica. S. italica alba. S. bifolia and vars. Muscari botryoides and white var. M. azureum. Tulipa Greigi. T. persica. T. kaufmanniana. T. sylvestris. Iris reticulata. I. reticulata Krelagei. /. Danfordics. I. bakeriana. I. balkana. I. Cengialti. /. olbiensis. I. pumila and vars. /. ChamcEiris. I. tolmeana. Lilium croceum. L. longiflorum. L. Browni. L. Krameri. L. elegans and vars. L. tenuifolium. Erythronium Dens-canis, vars. E. giganteum. E. grandiflorum. E. Hartwegi. Trillium grandiflorum. T. sessile. DWARF SHRUBS AND HALF-SHRUBBY PLANTS AND OTHERS OF RATHER SOLID HABIT FOR THE USE ADVISED AT p. 86 Polygala Chamabuxus. Polygonum vaccinifolium. Dryas octopetala. Cornus canadensis. Tiarella cordifolia. Asarum europceum. s i si THE ROCK-GARDEN 99 Salix reticulata. Andromeda tetragona. Gaultheria procumbens. Iberis sempervirtns. I. correafolia. Menziesia polifolia. Megasea, smaller vars. Armeria vulgaris. A. cephalotes. Genista saggitalis. Daphne blagayana. D. Cneorum. Spircea decumbens. Erica carnea, and other Heaths. CHAPTER XIII THE ALPINE GARDEN THIS chapter is for the most part a resume* of the teaching conveyed in some highly interesting and instructive letters to The Garden from Mr. Henry Correvon of the gardens of Floraire, Chenebourg, Geneva. No one is more intimately acquainted with the flora of the Alps than Mr. Correvon, or is better able to instruct and advise upon their use and adapta- tion to our gardens. In making an Alpine garden, and considering what plants are to adorn it, it must be remembered that in the mountains of Europe there are whole chains that are of limestone and others that are entirely of granite. Many of the failures in our rock and Alpine gardens are due to this fact either being unknown or dis- regarded. Each of those two great main geological formations has a flora proper to itself. It stands to reason, therefore, that if we plant a shrub or herb that belongs to the granite on a calcareous soil, or a lime- stone plant on granite, that we are only inviting failure. It is true that there are a good many Alpine plants that will grow in almost any soil, and a number of J* s^ ^4 --S THE ALPINE GARDEN 101 others that are fairly well content with one that is not their own, but there are a certain number that are not so tolerant, and if we would do the very best we can for the lovely plants of the mountain regions they should be given the kind of soil and rock that suits them best. From its very beginning then, if an Alpine garden is to be made in a calcareous soil let it be planted with the lime-loving plants and those that are tolerant in the matter of soil, but not with those that demand granite. Hitherto the mistakes of amateurs may have been excused, because in the books and plant lists that have till now been available the great importance of this has not been clearly and concisely put before them. If the Alpine garden is to accommodate a larger range of plants than those proper to the one soil, or if preparation from the first has to be made for plants of these two geological divisions, it is well that one distinct portion of the garden should be prepared with limestone and the other with granite. In this way it will not only be easier to work the garden and to know the destination of any newcomer, but the plants themselves will be in better harmony. I would earnestly counsel intending planters, if they have to do with a small space only, to be content with plants of the one or the other class of soil, because, as in all other kinds of gardening, the mere dotting of one plant, or of two or three only of a kind, will never make a beautiful garden, but at the best can 102 WALL AND WATER GARDENS only show a kind of living herbarium. Single examples of these lovely little children of the great mountains may be delightful things to have, and in the very smallest spaces no doubt will be all that is possible ; but we wish to consider gardening in its nobler aspects, not merely the successful cultivation of single specimens of the Alpine flora. In planning an important Alpine garden it should be remembered that in preparing homes for some of the best of these lovely plants, not only the rocky places must be considered, but the grassy ones as well, for the pasture land of the Alps is as bright with flowers as the more rocky portions. It is here that are found the Snowflakes and the Snowdrops, the Dog-tooth Violets and the Anemones of the Pulsatilla group. Here also are the glorious Gentiana acaulis, the bright gem-like G. vernat and in boggy places G. bavarica, near in size to G. verna, and sometimes mistaken for it, but different in the shape and arrangement of its more crowded leaves, and in the still more penetrating brilliancy of its astounding blue. These little gems are not often seen at their best in English gardens, but G. acaulis is a much more willing colonist, and in some gardens where the soil is a rich loam it grows rapidly and flowers abundantly and proves one of the best of plants for a garden edging. Though properly a plant of the pastures, the illustra- tion shows how kindly it takes to the rock-garden in England. The difficulty of imitating the close short turf of THE ALPINE GARDEN 103 the upland Alpine pasture is that here the grasses grow too rank and tall ; the only ones therefore that should be employed are the smallest of the wiry- leaved kinds, such as the short Sheep's Fescue with the tufted base. A true Alpine garden, it should be understood, is a place where plants native to the Alps alone are grown. It should not be confused with a general rock-garden where we have mountain and other plants from the whole temperate world. Besides those that one generally classes as plants, meaning flowering plants, there will be many of the beautiful small Ferns of the Alps to be considered, and the small shrubs whose presence is so important in the more prominent eminences of our rock-gardens and the tops of our rock-walls. Of the latter, in the true Alpine garden, the most important are the dwarf Rhododendrons, and nothing could be so fitting a groundwork or setting for the little bright-blossomed jewels that will be their companions. Especially in the mass and when out of flower, their compact form and dark rich colouring are extremely helpful in securing a feeling of repose in the composition of the main blocks of the rocky region, while their beautiful bloom makes them, when in flower, some of the loveliest of dwarf shrubs. Here again it must be noticed that care must be taken to suit each kind with its geological require- ment. The genus Rhododendron is represented by three species in the Alps ; in those of Switzerland io4 WALL AND WATER GARDENS by R. ferrugineum and R. hirsutum, and in those of the Tyrol by R. Chamcedstus. Still further east, in the Eastern Carpathians, is found R. myrtifolium. It is with the two Swiss kinds that our rock-gardens are mostly concerned, though R. myrtifolium is also of value, and will grow in many soils, though it prefers sandy peat. Of these Swiss kinds R. ferrugineum is a plant of the granite, while hirsutum belongs to the limestone, as does also the R. Chamadstus of the Tyrol. Subjoined are lists of plants proper to the two main geological divisions. It will be seen that in each genus the species seem to be nearly equally divided, so that in a garden devoted to one or other there would be no exclusion of any of the more important kinds of plants. Those that will do well in either soil are not included in the list. If in the case of some plants proper to the one formation we find in England that they can be grown in the other, it will not affect the general utility of these lists, which are meant to point out the conditions under which only they are found in nature, and under which they thrive best in gardens. It must also be understood that the lists do not aim at being complete. They comprise only the most characteristic examples of the species special in nature to the limestone and the granite, and that have been tried and proved either in the Jardin d'Acclimatation at Geneva, the newer garden " Floraire," or at one of the two experimental stations in the mountains that are on the limestone and on the granite respectively. It must also be understood that a good number of «n ^ 5 — h •* C^ "> THE ALPINE GARDEN 105 the Alpine plants that we are familiar with, that are tolerant of a variety of soils, and that are so well represented in the best trade lists, do not appear here ; so that if it is not convenient to supply any plants with either granite or limestone, those named in the following lists may either be avoided, or we may be content with what success we may have in such a soil as we are able to give them. There are certain plants of the higher Alpine regions that are usually failures in English rock-gardens, of which Eritrichium nanum may be taken as a type. Others in the same list of what we know as difficult plants are : Androsace glacialis, Charpentieriy helvetica, pubescenSj wulfeniana, and imbricata ; Achillea nana, Thlaspi rotundifolium, Artemisia spicata ; Campanula cenisia, Allionii^ excisa, petr