Hello Friends,
I was just wondering as to why I could not use just the ordinary builder grit and garden soil as growing media? Grit will keep the aeration and drainage and prevent compaction, while the soil will provide the nutrition? The grit never breaks down and when it comes to repotting, tapping off the media shouldn't be difficult, I believe/
Do we necessarity have to think in terms of Akadama and pumice and lava and ...
Please advise and share your thoughts/experiences on this? BTW, I have to arrange for a good amount of growing media for my pine.
@Paradox - covered the problems with this type of mix very well. Prior to the 1970's this mix was in common use for bonsai in North America. Then people like Bill Valavanis and others began importing Akadama and Kanuma from Japan, and began seriously studying the theory and practices behind potting materials. The blend will work if you are careful about your watering, but the results will be inferior to other products.
The single best component for a bonsai mix is pumice. If you can not buy anything else, do spend the money to get pumice. Perlite is a fair substitute, but perlite is too light for use in shallow bonsai pots. Perlite is excellent in grow out containers, where minimizing weight is important.
Pumice is one of the few components that can be used at 100% for a range of species. It works by itself or in conjunction with other products.
If you understand how to water and fertilize with a particular mix, you can grow a tree in just about anything, even chunks of old automobile tires. But you will have better, more consistent results if you use one of the modern substrates. The modern substrates allow for a greater margin of error, the timing of your watering does not have to be as precise. Your fertilizer choices are more open. You can get away with going longer periods between repotting with modern substrates. With the old grit & garden loam mix, you have much less tolerance for errors.
Akadama, pumice & lava, is the current "gold standard". But there are many, many other mixes that are used to good effect. Read Michael Hagadorn's book "Bonsai Heresy" published in 2020 for a good explanation about why the Akadama-Pumice-Lava blend is superior.
One item that improves all bonsai mixes, no matter what you use. It is sifting for uniform particle size. As much as possible, you want all the particles to be the same size. Sift to remove fines and sift to remove coarse particles. This will greatly improve root health, by keeping air voids open in the mix. The type of sieve I am referring to is in the link below. All mixes, commercial or home made will be improved by eliminating fines and overly coarse particles.
It's always a good idea to sift the very small particles out of your soil before potting. This helps aeration by keeping your soil cleaner and reducing clogging around the drain holes. You may also want to sift unnecessarily large particles out to create fairly uniform particle size for even...
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