Using the right planting medium mix for bonsai trees is very important. The planting medium plays a role in supplying nutrients to your favorite bonsai tree, but the planting medium also needs to have good drainage, provide sufficient aeration, and be able to hold water.
Most online and offline bonsai stores offer ready-made growing medium, but making your mixed growing medium will save money, and provide proper control for your bonsai tree species.
The quality of the growing medium used directly affects the health and vigor of your tree. Trees that are unhealthy and less strong are very often planted in poor planting media. Or worse, planted with regular garden soil. This type of soil easily hardens when dry, which is very dangerous for the growth of bonsai trees and makes it difficult for watering water to absorb.
A good growing medium requires several ingredients to be considered a good planting medium for your bonsai, these include:
- Good water retention. The best bonsai growing medium must be able to absorb and retain sufficient water to supply moisture to the roots of the bonsai tree.
- Good drainage. The best bonsai planting media has a feature where when watering the water can flow directly from the bottom hole of the pot. Withholding too much water is also not good because it will damage the tree roots.
- Good aeration. The materials used in the bonsai growing media mixture must be large enough (gravel) to allow air gaps. In addition to providing oxygen to the roots, these air gaps also allow good bacteria and mycorrhiza which allow food processing to occur before it is absorbed by the tree’s roots and sent to the leaves for photosynthesis.
Type of Planting Media
There are two types of bonsai growing media, namely organic and inorganic. Planting media materials made from dead plants such as peat, leaf litter, or bark are classified as organic planting media. Unfortunately, organic growing media have problems that over time will reduce drainage. Some organic materials deteriorate, so over time they can become dangerous for the health of the bonsai tree. If you insist on using organic growing media, you should choose one that uses pine bark. Don’t occasionally choose compost because it can clump and hold water, making it difficult for water to come out of the bottom of the pot and causing the roots to become sick due to excess water (overwatering). This is one of the biggest problems and many bonsai beginners have the misconception that compost is good for plants, even though in reality it is not at all.
Inorganic growing media contain little or no organic material. Inorganic planting media is usually volcanic lava, calcite, and clay that has been burned. They may absorb less nutrients and water than organic growing media but are great for drainage and aeration. Limited absorption capacity also means we can better control the amount of fertilizer in the planting medium.
In conclusion, particle-based, well-structured, inorganic growing media allows water to flow quickly and fresh air to continuously enter the growing media. Meanwhile, organic planting media is dense/clumpy, hard, and does not have good aeration and drainage.
Planting Media Materials
The materials most commonly used for bonsai planting media mixes are Akadama, pumice stone, lava rock, organic compost, and fine gravel or sand.
- Akadama is high-temperature fired clay, which is produced specifically for bonsai purposes and is available in all online and offline bonsai stores. If you buy Akadama, keep in mind that it must be filtered before use. Akadama will also start to break down after about two years of use, reducing aeration. This means that changing the planting medium (repotting) must be done regularly. Akadama is somewhat expensive and is therefore sometimes replaced with fired clay or a similar growing medium.
- Pumice is a soft volcanic rock, which can absorb water and nutrients well. When used in a bonsai potting mix, pumice helps retain water and allows roots to grow very well.
- Lava rock also helps retain water and creates a good structure when it is part of the substrate.
- Organic compost consists of peat moss, perlite, and sand. Although it can retain a lot of water and not allow for good aeration and drainage, as part of a bonsai potting mix, organic compost can work wonders. Of course, with the right comparison.
- Gravel or sand can help create a bonsai growing medium that has good drainage. It is also used as a bottom layer in bonsai pots to improve drainage.
Recommended Bonsai Planting Media Mix
Each tree species requires a different potting mix, so be sure to check your bonsai tree species to find the optimal mix. Pay attention to the climate and average temperature in your location. If you live in a hot location, add more Akadama or organic compost to the potting mix to increase water retention. However, if you live in a wetter location, add more lava rock or sand to improve the draining qualities.
Every professional bonsai has a different composition. You will need to do a little experimenting to get the right composition for your bonsai tree and the location you live