20 MASSACHUSETTS HORTICULTURAL SOCIETY 



There are two principal modes of constructing a rock garden. 

 A miniature valley, that is the soil dug out four or five feet and 

 banked up on each side, or, if there is a natural slope, stones laid 

 firmly in it to form irregular steps or shelves, where the plants 

 may be put. Both plans are ec[ually good. In the Botanical 

 Garden at Kew, London, they have the sunken path with high 

 banks on each side, and at the Horticultural Society's Gardens at 

 Wisley, one hour's drive south of London, a big hillside has been 

 used to make shelves and steps, and so show off a great collection 

 of alpines. Here it has been easy to have a waterfall. At Kew 

 they have just a pool next the path here and there. No cement has 

 been used in these constructions, and it has not been found necessary. 

 Cement may be used in retaining walls, as will be shown when 

 that subject is reached, but for a rock garden the weight of earth 

 is usually not too great to be held up by well-placed stones without 

 cement; of course, large stones two or even three feet long are 

 used for the foundations. 



For a very small rock garden the bank seems easier and more 

 suitable, but in my own rock garden I have made the little valley 

 which has the advantage of banks facing north and south. Unfor- 

 tunately, the bed rock was so near the surface soil that we could 

 excavate only about one foot. 



It is extremely important to build with solid foundation and 

 a definite plan. The idea that any natural-looking mound of stones 

 heaped together will do for growing alpines is a hopeless mis- 

 take, because the plants must have definite and solid protection 

 for their roots. Mr. Farrer says: "Stone in nature is never dis- 

 connected; each is always, as it were, a syllable in a sentence. 

 Remember that, urgently: boulder leads to boulder in an ordered 

 sequence." There must be no cracks, air-spaces, or slipping down 

 of the soil. These are absolutely fatal, and it is a thousand times 

 easier to guard against them in the original construction than 

 after a number of plants have started to cover the stones. 



When one has decided on a rock garden and has got the stones 

 and earth together at the chosen spot, there is an almost overwhelm- 

 ing temptation to build too quickly, and to put in what plants one 

 has, for the sake of seeing the effect. This is a most dangerous 

 way to proceed. We have suffered from it for years, and have lost 



