Gardening on Rock

[Steve B]

The location of my garden is on rock. On caliche. I could pick another spot, but this one is convenient, and another would be much farther from the house.

Digging down more than a foot or so hits caliche. This presents a problem in that it is impenetrable by roots, and water runs off it.

I want to do a greenhouse, and do some raised beds, both for convenience, and easier on the back. But what about the floor? If I were to frame up a concrete pony wall, say one foot high and then fill the floor with good composted soil, is one foot or slightly more enough for the roots of most gardens? I could then use that pony wall as the base for a greenhouse. I know I would have to watch the water so as not to soak the soil.

TIA

Steve

[John McGaw]

In most of the Las Vegas area (where I lived) caliche was a fact of life and people managed to plant things successfully by the expedient of breaking up the caliche, correcting the myriad problems with the soil (OK, so what was there couldn't even be called soil), and then going at it with usual gardening practices (with addition of shade structures and irrigation). In the old days I'm told that dynamite planting of trees was considered normal. Later heavy equipment and cheap labor from down south were the solution.

[Steve B]

At least here, the caliche seems to come in layers, the widest about 12". So, one can dig a hole, 3x the diameter of the rootball, and go deep. If they can punch through the layer, there will be drainage. Otherwise, you're just making a bowl, and most stuff rots or drowns.

I lived in Vegas for a very long time, and am familiar with caliche. It ain't bad if you hit a layered deposit, or just run into the edge of one where it breaks up reasonably easy. But if you're the lucky guy who lands on top of a big deposit, it is pure d hell.

Steve

[Freebird11]

An informal design is most effective, and simplicity is very important. Unless the area is quite large, avoid the use of excessive numbers of plants or elaborate rock formations. The most desirable location is a steep bank that may be available at the back or side of the property.A pool of water or a miniature stream and waterfall will add charm to the rock garden. Trees are desirable to provide partial shade, and shrubs should be used for background. If adequate space is available, the garden may include paths made with flat stones or pine needles and steps on steep slopes to encourage closer inspection and greater enjoyment.Plan the rock garden for easy maintenance. The most attractive ones are usually so wide you cannot reach to the center to remove undesirable weeds, prune plants, or set out new species. A sufficient number of large flat or rounded stones should be present to serve as a place to walk or stand while doing maintenance jobs in the garden. These must be deeply imbedded to provide secure footing as you work.A rock garden should express the creative ability of the gardener to use the terrain and plant materials that are available. Each garden should be a unique development and not a reproduction of one that has been observed on other residential or public property.

'Steve B[_6_ Wrote:

[rgrdsprashant]

Some homeowners design rock gardens to exploit rocky slopes in their yards. Others, like me, import rocks into yards that are flat and rockless; we need stronger backs, but the effort is well worth it.

Another consideration that can influence the design of rock gardens is space. I am allotting but a small space for my rock garden. In larger spaces, the goal is often to create sprawling, naturalistic rock gardens. But given my space restrictions, I'm contenting myself with what amounts to a round raised bed made of select rocks. This design fits neatly into the nook I have chosen for it. My small rock garden won't be in the way when I mow my lawn, nor will it require much maintenance.

Yet a third design consideration is color. I have a collection of attractive red sandstone pieces; they will provide the structure for my rock garden. In turn, this choice will influence my plant selection. I want a color scheme that will work well with the red sandstone. I would like some plants with a hint of red in them, but also some plants displaying silver, yellow and white.

The sandstone with which I'm working is hardly the most durable of materials. Indeed, many of the pieces are crumbly, well on their way to becoming soil! But beauty was my goal, not longevity.

Rock gardens normally achieve some elevation above the surrounding ground. In this case, that means laying a first course of rocks and soil, then building upon it. In Step 2 I lay the first course....