Bonsai soil is a special type of soil that is designed to meet the needs of bonsai trees, which are miniature versions of larger plants. Bonsai soil has to provide good drainage, water retention, aeration, and nutrients for the bonsai tree. Bonsai soil is usually a mix of different ingredients, such as pumice, akadama, compost, chicken grit, and lava rock. Each ingredient has a specific role in the soil mix:
- Pumice is a soft volcanic rock that absorbs water and nutrients and helps retain moisture for the tree.
- Akadama is a hard-baked Japanese clay that improves aeration and oxygen flow to the roots. It also breaks down over time and needs to be replaced every few years.
- Compost is an organic material that provides nutrients and some water retention for the tree. However, it should not be used too much as it can compact the soil and cause root rot.
- Chicken Grit is a coarse material that helps with drainage and prevents waterlogging. It can also be used as a bottom layer in the pot to facilitate water flow.
- Lava rock is another volcanic rock that absorbs and releases water gradually. It also adds structure and prevents soil compaction.
The exact proportions of these ingredients may vary depending on the type of bonsai tree, the climate, and the personal preference of the grower. However, a general guideline is to use 50% akadama, 25% pumice, and 25% lava rock for deciduous trees, and 33% akadama, 33% pumice, and 33% lava rock for conifers. The pH of the bonsai soil should be neutral, between 6.5 and 7.5. Bonsai soil is not just ordinary potting soil. It is a carefully crafted mix that ensures the health and beauty of bonsai trees.