122 GARDEN PLANNING AND PLANTING 



excellent plan, however, when tree roots are used, is, in all suitable 

 places, to wedge in pieces of turf, grass side downwards, to aid in 

 making the foundations of the structure less likely to fall to pieces. 



A rock garden should be in an open position away from tall- 

 growing trees, as not only do many plants fail in a shady situation, 

 but the roots of the trees would soon impoverish the soil. The usual 

 idea of a rockery is often a bank on which stones are grouped in 

 irregular fashion, with plants dotted here and there. This wrong 

 impression is no doubt due to the fact that Alpine plants are gener- 

 ally found at high elevations on hills and mountain sides. They 

 grow in such positions, however, because the trees and other coarser 

 vegetation will not allow them to thrive at lower elevations. In 

 making a rock garden the mounds of soil, not the stones, must be 

 placed in position first. The bases of the stones should as far as 

 possible rise out of the soil, the crevices between the stones or 

 rocks being filled with soil, and Alpine plants put in to hide the 

 seams where visible. If mounds of soil are used to give height and 

 effect to the garden any mould available may be used, but on the 

 top of this a foot or fifteen inches of good soil should be placed, most 

 of this being turfy soil, and a small portion peat if it is desired to 

 grow Heaths or other peat-loving subjects. When planting, the 

 special requirements of certain plants must be considered, and sand, 

 leaf mould, or the small pieces of rock left over may be worked 

 amongst the soil immediately surrounding their roots. 



Having put on the loam to the desired depth, the stones may be 

 built up in any way that good taste suggests, spaces with more or 

 less surface being left, which will in this way form beds for the 

 different plants. The spring of the year is undoubtedly the best 

 time to construct a rockery, for the reason that the soil will have 

 time to settle and the stones to become fixed in their positions before 

 the next winter's frost. Although it is not advisable to keep the tall, 

 fast-growing rock plants and the smallest Alpines altogether distinct 

 and separate, they must not be too freely intermixed, or the former 

 will soon spoil the latter. Give the choicer and smaller-growing 

 plants the best positions. When the rockery is once established it 

 will be necessary every year to look carefully over the plants and cut 

 out any pieces of the common kinds that are encroaching on the 

 ground set aside for the choicer plants. If the extent of the ground 

 permits of their use, a few dwarf Pines and Japanese Maples maybe 

 used ; the low-growing Brooms, notably Cytisus Kewensis, C. Be\ni, 

 C. purpureus, and C. Ardoini, add beauty and variety to the garden. 



