While thinking of all the places where rock gardens are to be seen or of sites where rock plants might be growing, there seem to be three types of terrain requiring very different efforts on the part of man.
The more hopeful areas are those supplied with natural rocks and perhaps with small plants or native wildflowers, dwarf ferns, and even lichens and mosses.
With a bit of further help from man, a very convincing and attractive rock garden can be readily made. But not all rocky areas are equally suitable for this kind of planting.
Rocky Seashore And Woodland
A rocky seashore may grow almost no vegetation, as the high tide sometimes sweeps it with high winds, and the soil is too salty for most plants.
A rocky woodland may be far too shady for any but ferns, and it seems unwise to cut down many trees to let in the sun.
Or the rocks may have been piled up so loosely by the glacier that soil and moisture soon fall away.
Or the ledge may have a few crevices, which are narrow and horizontal, unfitted for the insertion of plants.
Rebuilding Of Rock Gardens
Situations partly natural but requiring much rebuilding before plants will be happy therein are abandoned:
These include:
- Stone quarries
- Stone foundations of old buildings long burned or decayed
- Stony pastures in which there is enough outcrop of the ledge or lost boulders to discourage the grazing cow, or
- Stony bed of a small brook when most of the water flow can be controlled by dams and hidden culverts
Skeleton Foundation In A Natural Position
These sites already have a skeleton foundation of boulders in a natural position, and a few rocks more may be added by man (with skill and labor) and then plants inserted.
It is a great help to the finished site effect to have the spot already marked as a rocky area by the act of nature or the earlier operations of man.
No Rocks Exist at All
The third problem is where no rocks exist at all (or perhaps a few casual boulders left by the glacier or some previous owner).
Then the rocks must be brought in (with much labor, financial and physical), and unless they are skillfully placed, the effect is poor geology, and only weeds are happy there.
Without some knowledge of nature’s way of staging rocks in the soil, the result may look like a cemetery or as if the pile was pushed there by a powerful bulldozer.
Pleasing Rock Gardens
But many a pleasing rock garden (and others not so pleasing) began as bare soil or a forest of weeds.
To be successful in geology and ecology (relation of the plant to the site), there must be some quick changes in level in this bit of land, and the feeling that rocks might have been left there by natural forces, although further moved about by the present owner.
On flat terrain, not even modern mechanical machinery can make a rock pile convincing, but all were dumped from a cart by some giant with a strong back and no brains.
Rocks In A Roadway
Sites to which rocks may be convincingly added are such steep cuts or fills along a roadway or path:
- Areas naturally sunken or big holes left by a previous owner;
- Sides may be loosely walled with goodly rocks;
- Retaining walls laid with soil in a random pattern of rocks, back slanted to resist the pressure of the soil behind
- Steep slopes of sand or poor soil, at present nearly without vegetation, but upon which rocks and special soil can be placed.
Good Topsoil Producing
If the present slope is covered by fairly good topsoil-producing lawns, shrubs, or weeds, then the soil and plants should be removed down to subsoil.
The soil thus stripped may be used elsewhere or sifted to go in the soil mixture for the planting.
Your zeal may still equal the challenge if no rocks are on the site.
To strip first the soil and nature’s planting and start with nothing on bare subsoil is the final test of your ambition to have a garden among rocks.
44659 by Stephen F. Hamblin