HARDY HERBACEOUS PERENNIALS. 



345 



is very important. Where atmospheric and 

 mechanical conditions are favourable, the 

 chemical combination of the soil is of second- 

 ary consideration. So large a proportion of 

 ornamental plants are contented with the soil 

 which most cultivators provide for all alike — 

 even though in nature they seem to have pre- 

 dilections — that where an amateur has only 

 one rockery it would be too perplexing to 

 study the partiality of every plant, and to re- 

 member every spot where lime-lovers or their 

 opposites had been growing. I have some 

 rockeries where both soil and rock are adapted 

 exclusively for lime plants; others from which 

 lime is kept away, and where both soil and 

 rock are granitic; but the great majority of 

 plants thrive equally well on both. 



Whatever the character of the soil may be, 

 we must take care that it does not retain stag- 

 nant moisture, and yet it must not dry up too 

 readily. Plants must be able to penetrate it 



Fig. 418.— Correct arrangement of stones to provide root 

 accommodation for plants. 



easily with their roots, the lengths of some of 

 which must be seen to be believed. Good loam, 

 with a little humus in the form of leaf-mould 

 or peat, and half or three-quarters of the bulk 

 composed of stone riddlings from the nearest 

 stone quarry, and varying in size from that of 

 rape-seed to that of horse-beans, make up a soil 

 with which most alpines are quite contented. 

 The red alluvial clay of Cheshire, burnt hard 

 in a kiln, and broken up or riddled to the 

 above size, is an excellent material mixed with 

 a little soil and a little hard stone. Where you 

 are convinced that lime is useful, it may be 

 added as pure lime, not planting in it till 

 thoroughly slaked by mixture with the soil. 

 All alpines delight in a rough surface-dressing, 

 as it keeps the top of the soil sweet and moist, 



and prevents their leaves being fouled. Use 

 for this purpose the same riddled stone as 

 described above, which is better than gravel 

 as round peebles are easily washed off' the slope 

 by rain or in watering. 



Having constructed our rockeries, we must 

 furnish them with plants. It is better not to 

 be in a hurry to see the stones covered. It 

 would be easy to cover them with growth in a 

 single season, but we must not degrade choice 

 alpines by putting them with Periwinkles, 

 Woodruff, St. John's Wort, Dead Nettles, 

 Creeping Jenny, fast -running Sedums, and 

 Saxifrages, which do duty for alpines on raised 

 structures of roots or stones in the shady, 

 neglected corners of many a garden. Some of 

 these things are very pretty and desirable in 

 their way, but such subjects must be carefully 

 kept off the alpine rockery. As a rule, nothing 

 should be planted which cannot be easily and 

 entirely eradicated. 



If different rockeries, or separate parts of the 

 same, can be assigned to rapid growers and to 

 dwarf compact plants it will be an advantage. 

 There are many subjects which belong to the 

 class of alpines which require to be displayed 

 in a broad and high mass to do them full 

 justice. Aubrietias, for example, and Veronica 

 prostrata should look like purple or blue cata- 

 racts; others should be unlimited in breadth, 

 like the dwarf, mossy Phloxes and the bril- 

 liantly-coloured Helianthemums. They do not 

 like being cropped round to limit their growth, 

 and if there is not enough room for them they 

 had better be omitted, as the small and delicate 

 gems of the collection must run no danger of 

 being smothered by overwhelming neighbours, 

 and this requires both careful arrangement 

 and constant watching. When first I began 

 to cultivate alpines I planted somewhat indis- 

 criminately together things which I thought 

 would make an ornamental combination, but 

 the weaker soon became overwhelmed in the 

 fight with the stronger, and there was nothing 

 to be done but to build a new rockery and 

 plant it more carefully. In this way I have 

 now constructed at least a dozen rockeries, 

 trying each time to benefit by past experiences 

 and to exclude weedy plants. The first and 

 second made still continue, and are still flowery 

 wildernesses in spring, but everything choice 

 and delicate upon them has either long ago 

 perished or been transferred to new quarters. 

 Visitors to my garden in spring who are not 

 connoisseurs in alpines think these wild rockeries 

 far more ornamental than the half-bare stone- 



