Landscape Edging

Although a rock garden is frequently built in garden areas specifically chosen for the purpose, it can also be constructed on any area of ground you have no other use for. The only requirement is good drainage since rock and mountain-growing plants do not grow well in water-bound soil.

The best base for a rock garden is a sloping area whereby surface water can easily run off. It is not the presence of water that can be a problem, but its inability to run off. In fact many excellent rock gardens are associated with natural and artificial streams, since running water is the natural habitat of many of the plants used to populate rock gardens.

The main soil areas should be gritty rather than well composted to simulate the natural environment of the plants, though the plants themselves should initially be bedded in rich soil to help them establish. A rock garden is frequently called an Alpine garden, and Alpine conditions are associated with excellent drainage through loose gritty soil.

A rock garden is not a currant bun, constructed by sticking rocks and stones into a mound of earth. The area chosen should be excavated, then the bottom perimeter of the rock garden lined with stones. Then one or two large rocks should be laid which will protrude above the surface when the garden has been completed. These are the main rocks, around which other rocks and stones can be laid.

The spaces between all of these rocks should be filled with increasingly smaller stones and finally with gritty easily drained soil. Drainage is critical for a successful rock garden. Mixing sand with topsoil is a good way to promote drainage.

The best stone to use to construct a rock garden is limestone, though granite and any local stone will probably suffice. Once the garden has been set up, make pockets among the rocks and stones and fill with good composted soil in which to place the plants.

You can mix the soil with washed sand to remove any residual salt. Do not sow seed, but purchase bedding plants such as heathers and other ericaceous plants which do very well in rock gardens, and also Alpine plants. Perennials are best, though some annuals can be used.

Alyssum, delosperma, geraniums and verbena all do well in rock gardens, with some gypsophilia to break it up. Your local garden center will able to help you with the best plants for your area.

The main secret behind a good successful rock garden is to ensure that the rock foundation is built first, and then the drainage and the introduction of gritty soil, then the excavation of small pockets between the rocks for the plants which should be filled with rich compost, then finally the plants.

What you must not do is to build a mound of earth, stick in some stones, then some plants. As stated earlier, gardeners call this a currant bun. Think Alpine. Think mountains, rocks, little soil and running streams.

You can construct a running stream with some polythene, some 1” plastic piping and a water pump – and don’t forget the water. Lay the polythene ( any flexible plastic will do) between lots of rocks and stones with plants enjoying the running water, and lead it to a small pool: even a foot or so diameter will do, from which it can be pumped back to the top of the stream. It’s easier than you think.

You have the ideal basis for a rock garden. Providing you base it on a bed of rocks and stones, and not earth.