Bonsai trees are quite interesting, getting fuller tree structure in a miniature form, it is nature and art at the same time. To ensure your bonsai grows properly, one of the key things to consider is the bonsai soil chosen. Many of the newbies tend to forget about the specific needs related to the type of soil required, but the right substrate has a bearing on the tree’s well-being, expansion, and lifespan. In this article, we will cover everything about bonsai soil and its types, its respective advantages, and how you can select the most appropriate mix for the particular tree.
Why Is Bonsai Soil Different?
Bonsai trees are small and grown in pots so they have specific requirements for soil and growing conditions and this is why the soil is specifically designed and manufactured for these trees. Such small trees tend to need certain watering styles levels of nutrients and depth of root systems. Everyday soil tends to get compacted and retain so much water leading to drowning of the roots of the bonsai plants. On the other hand, balk soil helps in good water drainage, oxygenation of the root systems, and retention of moisture which is vital for the overall health of the tree.
Fundamental Segments of Bonsai Soil
A well-balanced bonsai soil mix typically includes a mixture of inorganic and organic components. Here’s an overview of the most common ingredients:
Akadama
This type of huge-grained Japanese soil is extremely popular among those who are into bonsai planting. Akadama is a type of clay that is easily moldable, so it is nice because it holds moisture and drains well. it is easy to see when fertilizer needs replacing. however, akadama soil is viewed as quite rare and it tends to be expensive which makes it hard to find outside of Japan.
Pumice
Pumice is a lightweight, volcanic stone that adds excellent drainage and helps bonsai roots establish well. It also retains some moisture while being porous, which prevents waterlogging. Pumice is an essential component in many bonsai soil mixes due to its balanced properties.
Lava Rock
This rock is a porous stone and being volcanic, it is used in most soils that are meant for the bonsai trees. Like pumice rocks it helps with drainage and aeration of roots but unlike them, Lava rock provides excellent support for the roots. Since they have rough surfaces, it quickly helps the roots expand making it ideal for trees that are placed In shallow pots.
Organic Compost or Pine Bark
Organic materials such as compost or pine bark are used in bonsai soil to provide nutrients for the tree. However, too much organic matter can cause excessive moisture retention, so it’s typically added in small amounts.
Gravel
Gravel or uncultivated sand is used in bonsai soil mixes for excellent drainage. It ensures that water doesn’t stagnate around the roots, which can lead to root rot. Gravel is often layered at the bottom of the bonsai pot as well.
The Role of Soil in Water Retention and Drainage
Moisture retention and drainage are essential in the cultivation of bonsai trees. If too much water is held in the mix, then the seeds are likely to drown. Too little moisture might dry out the seeds. The secret is to ensure that water is retained but excessive water is drained out.
Different species of bonsai trees have differing needs when it comes to soil. For instance:
- Tropical bonsai trees such as Ficus or Jade prefer soils with better moisture retention due to their high water needs.
- Pine or juniper bonsai trees, on the other hand, require fast-draining soil to prevent excess moisture and root rot.
Customizing Your Bonsai Soil Mix
Making the perfect bonsai soil mix requires understanding your bonsai species and environmental conditions. Naturally, bonsai soil is mixed in ratios depending on the species, climate, and watering schedule. A commonly recommended mix for deciduous trees includes 50% akadama, 25% pumice, and 25% lava rock. For coniferous trees, a 30-30-30 mix of akadama, pumice, and lava rock is often used.
Ready-Made vs. DIY Bonsai Soil Mix
While some people choose to source their materials for making their bonsai soil, most choose pre-made bonsai soil mixes that are available mostly online or at particular gardening shops. These mixes are pre-made, and this is very helpful for beginners since they are made with specific trees and conditions in mind.
Bonsai Soil for Different Tree Species
Bonsai soil is used depending on the kind of tree that is being used. Here is how some trees specific soil use has been utilized:
Ficus Bonsai Soil
Since ficus bonsai trees are characterized as tropical bonsai trees, they prefer well-aerated soil that can hold water well. Ficus’ roots have good hydrocontact, so a mix of 40% akadama, 30% pumice, and 30% organic materials such as fibrous peat works for Ficus as It needs moisture without becoming oversaturated.
Juniper Bonsai Soil
For junipers, quick-draining soil is best as they do not like soggy soil. A combination of 60% akadama, 20% pumice, and 20% lava ensures the soil does not retain too much moisture.
Pine Bonsai Soil
Well-drained and slightly acidic soils are preferred by pines. 40% Akadama, 30% Pumice, and 30% Lava Rock mixture do a good job of providing reasonable drainage while keeping the pH slightly acidic for the tree’s roots.
How to Properly Pot Your Bonsai Using Bonsai Soil
When repotting your bonsai, it’s important to ensure the tree is in the right soil mix to support its health. Here’s a step-by-step guide:
Prepare the Bonsai Pot
Ensure that your pot has drainage holes to allow excess water to flee. If needed, cover the holes with a mesh screen to prevent soil from washing out.
Add a Base Layer of Gravel
Place a thin layer of gravel or uncultivated sand at the bottom of the pot. This promotes drainage and prevents the roots from sitting in water.
Position the Tree
Gently place your bonsai in the pot, spreading out the roots. Use chopsticks or your fingers to work the soil into the roots and around the base of the tree.
Fill with Bonsai Soil
Add your custom or pre-made bonsai soil mix into the pot. Confirm that it fills the pot and covers the roots while leaving a small gap at the top for watering.
Water Thoroughly
After repotting, water your bonsai thoroughly to settle the soil and hydrate the roots.
Signs Your Bonsai Soil Needs Changing
Like all living things, bonsai trees need regular care, and this includes repotting. Over time, bonsai soil can break down and lose its useful properties. Here are some signs that your bonsai soil needs changing:
Water doesn’t drain properly
If water pools at the surface or takes too long to drain, the soil might be compacted.
Root growth is limited
If roots appear bound or have difficulty expanding, the soil may be too compact or depleted of nutrients.
Foul odor
A bad smell indicates that the soil is holding too much moisture, leading to root rot.
Conclusion
The correct bonsai soil is the backbone of a healthy and well-balanced tree. No matter if it is a juniper tree or a ficus or a pine tree, the appropriate amount of akadama, pumice, lava rock, and organic matter, goes a long way in enhancing root development, moisture availability, and drainage. If you adapt your bonsai soil to meet the unique requirements of your tree, you’ll increase the chances of it surviving for an extended period and also looking good.