September 8, 1906 



HORTICULTURE 



261 



Rockeries and Alpine Gardening 



"What did you say?'' "Where can I go to see a good 

 illustration of rockery and alpine gardening?" My 

 reply was, ''I really don't know" — which is a fact. Is 

 it possible that nobody knows any thing about the beau- 

 ties of these higher-up plants and their very simple 

 requirements? Surely there are scores if not hundreds 

 who are as well- acquainted with them as I am. so I 

 am going to make a plcament for rockery gardens gen- 

 erally and alpine plants in particular. There should 

 be a better word than "alpine." On a table rock, only 

 last year, I saw overhanging tlie Mississippi river, fifty 

 feet above the water, a grouji of the slender hare bells 

 with more than five hundred open flowers. They sui'ely 

 were not alpines and there are very many beautiful 

 dwarf native plants which belong to elevated surfaces 

 rather than the level ground, yet they cannot be classed 

 as alpine plants. The list given below contains some 

 of these. 



MATERIAL REQUIRED 



The necessary material to make a rockery to properly 

 grow plants on is rich sandy soil, and this must be in 

 sufficient quantities to insure a mean depth of not less 

 than eighteen inches in any part of the structure. The 

 fallacious idea that rock plants do not require an3'1hing 

 but poor soil to grow in and very little of that is so 

 common that it is not at all surprising to see — as one 

 does occasionally — a few scarecrow-like plants stuck 

 between a few stones on a so-called rockery. For some 

 plants leaf mould — humus like decayed manure — heavy 

 clayey loam, very old disentegrated mortar, and very 

 coarse sand are desirable; for certain plants a mixture 

 of all these may be advantageously used. 



The most satisfactory stones to use are sand stone, 

 lime stone, tufa, some granite boulders, soft and porous 

 bricks, new or old: the least desirable of all are fur- 

 nace clinkers, except for filling deep places. Sufficient 

 quantities of all the necessary kinds of material should 

 be obtained and conveniently placed, so that the work 

 may be quickly done. 



WHERE IS THE BEST PLACE? 



Wliere to build the rockery depends upon the space 

 of ground afvailable for the purpose and the size desired. 

 A sunny, sheltered position is a desideratum. Over- 

 hanging trees must be avoided. The shape will be de- 

 termined by the immediate surroundings. The center 

 or foreground of a lawn are not desirable positions. 

 The actual base line of the rockery should be nearly 

 level and if somewhat depressed so mucli the better. 



Xever have the base line on a hill where the wat'^r mil 

 wash and run away from it. The surfaces of all 

 plateaus and bays should be finished level, so also 

 should the steps or treads of the pathways; in fact it 

 should be borne in mind to construct the work so that 

 the water will run into the bulk of the soil at the back, 

 instead of running over the outsides. This caring for 

 surface levels is very important. \Miere more than one 

 or two tiers are made they should not be more than 

 four feet wide at the broadest point. These tiers bhould 

 be irregular in shape and yet, withal, there must be 

 some tentative system in -the whole work. Make the 

 pathway wide, not less than two feet in the narrowest 

 part, and the treads from four to eight inches high 

 and no higher. The breadth of steps may vary consid- 

 erably — none less than a foot wide. The interstices 

 between the stones are to be filled in with quarter-inch 

 gravel or limestone. The bays, plateaus and pockets 

 are to be variable in size and shape. The rims tc hold 

 the water must be level to a certain height wheie the 

 stones do not touch or are distant apart so that when 

 the planting is completed the surface of the soil in the 

 small bays will be an inch and a half below the level 

 of the rims, and 2 to 2 1-2 inches in the larger ones 

 for holding water. The water should percolate through 

 the soil and not run off it. Long and thin stones or 

 slate should be set perpendicularly in the soil so that 

 at least a few inches appear above the surface and 

 whieli may form partitions between tlifi colonies, or 

 they may form the face of the next group above; let 

 these stones be entire if possible. Keep the diilerent 

 kinds of stone together as much as possible, except per- 

 haps that some particular different specimens may be 

 placed on conspicuous corners or central elevations. 

 Bear in mind that the rock work is not the objective 

 feature, but primarily it is of the greatest importance 

 and necessity and must be so considered. Eepetitions 



