344 



THE GARDENER'S ASSISTANT. 



shaped rockery is about 4 feet high, and 6 or 

 7 feet through at the base. The length is im- 

 material. If the long sides face north-east and 

 south-west it will afford perhaps the best variety 

 of aspect; but the amount of sunshine each 

 plant gets will depend on the arrangement of 

 each stone as much as upon the main structure. 



Fig. 417. — Method of planting Fissures. 



There cannot be too many projections, and care 

 must be taken to leave no channels between 

 the stones by which the soil can be washed 

 down to the base. Overhanging brows, beneath 

 which plants can be inserted, are very useful; 

 large surfaces of stone may here and there be 

 left exposed, and irregularity of form is far 

 better than symmetry. A formal arrangement 

 of flat pockets or nests offends the eye without 

 helping the cultivator, as the requirements of 

 alpines as regards slope of surface and moisture 

 at their roots are very various. The degree of 

 slope from the base to the summit of the barrow 

 should not be uniform. In some places there 

 will be an irregular square yard of level on the 

 top, bounded by large cross keystones, for which 

 the largest stones should be reserved. In other 

 parts the sides will slope evenly to the ridge; 

 or the upper half may be perpendicular, leaving 

 only wide crevices to suit the taste of certain 

 plants. If the blocks are very irregular in 

 form, and their points of contact as few as 

 possible, providing only for secure interlocking, 

 there will be plenty of room for soil to nourish 



the plants. Ever -changing variety of stone 

 surface, both above and below the soil, is the 

 object to be aimed at, and any sort of symmetry 

 must be avoided. 



The facing rockery is dependent upon the 

 natural shape of ground -surface. Wherever 

 there is a steep bank facing south or east it 

 may be utilized for the growth of alpines. The 

 stones, as before advised, should be large and 

 unshapely, and be buried to two-thirds of their 

 bulk, and form a very uneven surface, all being 

 interlocked from top to bottom as described. 

 Rockeries of this form are less liable to suffer 

 from drought; if the surface covered is large, 

 access to all parts should be provided by con- 

 venient stepping-stones, because although every 

 stone in the structure ought to be capable of 

 bearing the weight of a heavy man without 

 danger of displacement, it is better not to have 

 to tread upon the plants. 



The sunk rockery is perhaps the best of all, 

 but entails rather more labour in construction. 

 Where subsoil drainage is perfect, a sunk walk 

 may be made, not less than 10 or 12 feet wide, 

 with sloping sides. The sides may be faced 

 with stones, as described in the facing rockery, 

 and all or part of the excavated soil may be 

 made into a raised mound, continuing the slopes 

 of the excavated banks above the ground-level, 

 and thus combining the facing rockery and the 

 barrow rockery. If the outer line of this por- 

 tion above the ground be varied by small bays, 

 every possible aspect and slope may be provided 

 to suit the taste of every plant. However, 

 unless drainage is perfect, a sunk walk, rising 

 to the ground-level at each end, would not be 

 feasible. But a broad walk, excavated into the 

 side of a hill and sloping all one way, could be 

 adapted to a structure nearly similar to that 

 described, or the ground may be dug out in the 

 form of an amphitheatre to suit the taste or 

 circumstances. 



Whatever the form of rockery adopted, let 

 the situation be away from the influence of 

 trees, beyond suspicion of the reach of their 

 roots below, or their drip, or even their shade, 

 above. Trees which only shelter from high 

 winds are so far serviceable, and so are walls 

 and high banks. There are few alpines for 

 which a storm-swept surface is good, but trees 

 are objectionable where they lessen the light, 

 which is an important element in the welfare 

 of most mountain plants. The shade and shelter 

 afforded by the stones and form of the struc- 

 ture itself is the best kind of shade and shelter. 



We now come to the subject of soil, which 



