Making A Rock Garden And Landscaping Rocks
Where do I get the stones for my?
Happy is the gardener if the rocks are already on the property, such as a natural ledge, an old quarry or a boulder-strewn field. Then, man has merely to rearrange a bit the stones provided by nature, addand a few plants and the miracle is complete. But sometimes there are no stones for many miles, as on the southern shore of Lake Michigan, where there is just sand beach and clay cliffs. For a rock garden here the stones used were brought from Concord, Massachusetts, and the owner called it her “garden of precious stones.” The area had been built in a very convincing manner, but there was not another pebble as large as an egg for miles along that lake shore.
Avoid Assorted Rocks
I hope your rock garden is not a geologist’s collection of assorted rocks brought in from every State in our country, an idea, perhaps, suited to the Pilgrim Monument at Provincetown, Massachusetts, but not for a convincing rock garden. So, for economy of labor and effort, as well as natural appearance, use the stones native to the area where you live. These may vary from pudding-stone to coral, from red sandstone to smoky quartz, froth grey shale to white marble, from weathered glacial boulders of mixed ancestry to flat slabs of volcanic origin. As long as the rocks are apparently local, and not too assorted as to chemical character, the source of your stones is decided by the rules of the game.
Handle Rocks Carefully
To get the appearance of age and stability, use as many as possible of the landscaping rocks that already have a weathered or mossy face, keeping these faces turned to the light of day. Even if common sense and the rules of rock-pile building suggest that the weathered face be buried for greater stability, yet your greatest ingenuity must be used to place each rock so that it still will be stable and show its weathered face. This means, also, that all rocks that are to be a part of the outer face of the garden must be handled as carefully as if they were glass bricks, not tossed about carelessly by workmen, not chipped by hammer or iron bar, but moved about on a burlap stretcher. All broken faces must be buried in the earth. In a large rock garden in one of our city parks the drill-holes in the stones are placed in full view! Whoever saw nature making drill-holes in her rocks?
Old stone walls make excellent hunting ground for special boulders, and in the northern States of America the glacial boulders, long buried in earth, will recover a weathered face in a few years. But freshly broken faces, unless the stones are very soft, will weather very slowly. Very hard stones can be washed with vinegar, tannic acid or other weak acid to open up their tiny crevices. Then, after a Winter of frost, water well with molasses, cheap sugar, manure water or even diluted chemical fertilizers. Water frequently, and in a few years a film of grey or green will appear. But it is much simpler to pick stones naturally weathered.
Some stones, long buried, brought to the surface and left to a Winter’s frost, may break up into rubble, or defy all the elements and become unchanged. Avoid the use of a major part of very soft rocks (unless that is all that you can get), for a few frosty Winters will melt your stones to a gravel heap; while dark trap or white quartz will never show even crevices. The rocks of a seashore would seem usable, but the marine plant life and shell-fish attached to them will be visible for years. Sedums and primroses seem to be in strange surroundings, unless your sea-water rocks are rolled, but only above high tide.
Avoid Small Rocks
Use as large rocks as your purse, muscle and mechanical equipment can provide. But there is a limit to this, and one pleasant stoneless meadow near a lake now has giant boulders set up by machinery in correct imitation of the Giants Causeway or Fingal’s Cave. Yes, this even has a cave, and Daphne eneorunt and cotoneasters drape well its entrance. Usually, your stones are too small for their job, and we make pyramids of eggs or oranges in effect. Or if these are scattered about on the terrain we have a cat cemetery or a children’s playhouse. Most of the stones should be at least a foot in larger diameter, and those smaller used for filling. In Chinese gardens it is permitted to cement little ones together to make bigger ones, and the cement may be visible. But it is suggested that the cement show as little as possible, and mix the cement to match the color of the stones. As soon as cemented, put some of the soil prepared for the beds right upon the soft cement and leave it there until washed off by rain. This will make the artificial joints look more like crevices and less like a cemented wall.
Shapes of Rocks
The two extremes as to rock shapes are the rounded waterworn (or glacial) “eggs” and the flat shale slabs. The rounded eggs are very abundant in river beds and in glacial fields. Often they are the only choice, but man’s ingenuity is strained to the utmost to make any stratified effect from them. No matter how carefully laid in imitation strata, still the whole pile looks unstable (often it is), and no matter how carefully “op-tilted” and “hack-set,” small torrents of water will rush down their joints and wash out the soil and the plants. A garden all of rounded boulders is a puzzle indeed to build. Yet worse is a mixture of rounded and flat stones, in effect of the rip-rap of a railroad embankment. Better separate the two types, and have a part of the area “egg” like and a part stratified, as if two separate geological regions.
When first laid up, the new rock garden looks like a convict’s stone pile – all rocks. Perhaps it will continue to look that way for many years, but usually, if at all suitably constructed and planted, the plants will soon grow too well, and the rocks become submerged in green and flowers. A steep hank apparently held up by green dianthus does not look stable, but the big stones are really on duty underneath. So the choosing and placing of the rocks are but the first moves in the game of making a rock garden.