The rock garden is a reconstituted evocation of wild nature as found in the mountains on stony slopes, where plants colonize the smallest gap between the rocks. The flora is very diversified and always colorful.
Choice of the site
The greatest difficulty consists in creating a very natural space: the rock should not seem to have come out of the hands of man, but should be the result of a natural rock fall.
To do this, choose a site that is already sloping or gullied by erosion. A rockery should never be "planted" in the middle of a garden: lean it against a low wall, a staircase or other construction, which it will dress with its wild aspect. The exposure should be sunny and the soil well drained.
Choice of rocks
The choice of rocks remains essential: use local stones that fit perfectly into the landscape and respect a uniformity of color. Don't combine very different rocks and stick to a single mineral origin: nothing is less natural than a mixture of pink granite, slate and limestone! Similarly, for the shape of the stones: if you decide to start with flat and flush shapes, do not include a round rock in the center of the composition! Select nice sized rocks to structure the rock garden.
Placement
Once the location is determined, construction can begin.
Install the largest boulders to structure the rock garden. Bury them at least a third of the way down to ensure a good hold for the whole. Create tiers that will allow the vegetation to be layered and retain the soil at the feet of the plants. The tiers should be placed in a very irregular way so as not to look like a staircase.
If your soil is clayey or compact, add tuff or coarse sand to lighten it.
Install plants in small groups of the same species in repetitive touches to create an impression of unity and keep the natural aspect. The tallest plants will be placed in the background, leaving the tapering plants to form cascades on the rocks.
Which plants?
It all depends on the desired look... Some will want to recreate the oriental charm of the valleys with dark and flat stones that will blend perfectly with azaleas, heathers and dwarf conifers for the large subjects, and columbines, perennial geraniums, campanulas and carnations for the smaller ones. Others will prefer a more classic rock garden composed of twisted rocks and carefree, colorful plants such as auberets, sedums, silverbells and saponaria. Anthemis and veronicas are also plants well adapted to this type of culture. It's all a matter of taste: it's up to you to compose the decor of your dreams!
