Soil for Bonsai Plants
- Bonsai trees require special soils and generally dn't do well in standard potting media.Bonsai image by syresZERO from Fotolia.com
Bonsai is the art of growing miniature trees in small pots that mimic the appearance of larger, older trees in nature. Although bonsai is associated primarily in the west with Japan, the art originated in China and is called "pen sai." Because of the small containers, the trees need frequent watering. The frequency of the waterings require soils that drain quickly and allow adequate air to reach the roots. Although the exact mix depends on many things, including the variety of tree and the size and shape of the pot, bonsai soil needs three main components. - Bonsai soils must retain a certain amount of water to allow it to be taken up by the roots. Different organic materials help the soil retain water. Some bonsai soils use shredded tree bark as the organic component. Other soils use sphagnum or peat mosses. Some home growers crush up leaves as the organic component. Whatever organic material you use, screen it through a #4 mesh. This mesh has four openings per inch. This prevents clumps from forming that could hold too much water near the roots.
- Drainage is very important in bonsai soils. Sand is a common additive to encourage drainage. However, sand is dense and does not allow much air to reach the roots. Often, a combination of sand and the materials used for aeration are used to create a soil that drains adequately for bonsai. Drainage is important because, depending on the tree, the bonsai needs to be watered frequently, sometimes even daily. Other trees can go as long as three days between waterings. Water must drain from the bonsai's roots lto reduce the risk of root rot in the trees.
- Aeration near the roots is required for any plant. Because of its frequent waterings, bonsai needs materials in the soil that creates gaps where air can accumulate. Traditionally, volcanic lava or baked clays are incorporated into bonsai soils to allow for adequate aeration. A traditional Japanese baked clay is akadama. Different American fired clays that work well include Seramis, Turface, and Oil-Dri. Different brands of cat litter made from fired clay also work well.
