Bonsai Rocks

 Using Ornamental Rocks...

If you want to increase the impact of your bonsai, introducing one or more rocks is a good idea. Solid, elemental-looking rocks can give the impression that a bonsai is part of a landscape. A single rock can resemble a rugged cliff, a towering mountain, or a rocky island. A group of smaller rocks, positioned as outcrops protruding from the soil of the bonsai container, can recall the rocky terrain in which the tree lives.

The use of ornamental rocks with a bonsai tree was always something of great importance in ancient times. This practice has become less used these days, but can add just that one final touch to your bonsai masterpiece. Excessive use of rock and statues around a bonsai is known as Saikei, but a single one or two rocks along with the tree still classify as a bonsai.

The choice of what type of rock to use basically is up to the bonsai artist. Personally, I use interesting and weathered pieces of granite and slate that I have collected from the wild, but you could basically use anything that looks natural and suits the type of tree for the bonsai, and the pot. Note that if you are going to use rocks collected from the sea, or estuaries, that these have been exposed to the elements for two years at least (such as in a corner of your garden) where this has allowed the salt and any other chemicals to leach from inside. If you do use a rock that has been exposed to chemicals or substances that are detrimental to your bonsai - either do not use it, or make sure that these substances are properly eliminated.

For your rock 'planting' you obviously need to find a beautiful rock that is harmonious and complimentary to the tree's structure and colours. Many types of rock exist around the world, but some are better than others for bonsai. The best kind for bonsai work is a hard type that will not crumble away. It should also have an important colourshape, and texture. Pay particular attention to the rock's shape and type. It should be intrinsically interesting. A round, smooth rock, for example, suggests a watery scene, so it would enhance trees such as willows. A bland rock is unlikely to produce a good effect. On the whole, pick a rock with a natural-looking shape, but you should not find this a limitation, because nature produces a wide range of fantastically contorted mountains, boulders and rocks. Pleasing texture and colour are also important: black and shades of grey are usually impressive.

A popular choice of rock is the Japanese Ibigawa rock. It is a volcanic conglomerate, a mixture of several rock types welded together by the heat of volcanic activity.

Do not use marble or quartz because their intensively shiny, glittering textures will detract from the natural effect of the trees. Frost may split the strata lines of sandstone and other types of sedimentary rocks.

You can use soft rocks such as lava rock and tufa, but don't rely on these too heavily as they can erode quite quickly. Soft rocks should never be used for clasped to rock or root-over-rock styles.