Akadama, particularly when mixed with other media, is a great medium for growing bonsai (see “All about akadama” for details).
Over the course of the last year, akadama has become harder to come by for several reasons:
- Global demand has increased.
- Mining slowed down due to heavier than normal rainfall.
- Shipping congestion has delayed shipments.
As a result, it might be the case that not everyone looking for akadama will be able to find it. What are our options when availability is limited?
- When possible, postpone repotting. If I’m on the fence about repotting a tree and I don’t have the soil for it, I might wait another year. Although this isn’t an option when water fails to drain at a reasonable rate, it is an option when the primary reason for repotting is to change the pot or planting angle.
- Avoid using akadama for young trees. I have yet to find that akadama performs better for young trees so I no longer use it even when it is available.
- Re-use bonsai soil. If you don’t have problems with pests or pathogens in the soil, you can save akadama-based soils, dry them over summer, re-sift them to remove the dust, and then combine them with other ingredients to create mixes that meet your development goals.
- Use alternative soil mixes. A variety of mixes can serve as good replacements for akadama depending on the development goals.
Young trees can grow well in a variety of mixes. I use 100% perlite or 100% scoria (lava rock) for most of my pre-bonsai. I’ve also used mixes that are 60-80% pumice with the remainder an organic-rich mulch or bark.
Recently collected trees or trees dug from nearby gardens can go into 100% pumice for one or more years while the initial container roots get established.
For mature bonsai, I’d try a few mixes and see which work best for each species based on my growing conditions. I’d experiment with pumice, scoria, decomposed granite, and possibly organic ingredients like bark or mulch.
I’m curious how pines will do with 50% pumice mixed with 50% scoria. Pine growers in Shikoku, Japan, use 100% “sand” that resembles decomposed granite so I’d try using mixes that incorporate that too.
Chojubai growing in 100% scoria
I typically carry akadama-based soils on the Bonsai Tonight Online Store but have been out of stock for some time. I’m expecting more soil to arrive next year between February and April, but I won’t know when until closer to the arrival date. I’ll be sure to post updates when I know more about the timing.
Have your own strategies for getting by without akadama? Feel free to share them in the comments below.
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