Akadama...My Experience

[Paradox]

Question- I know not many care about tropicals but this sounds like it might not be a bad thing for ficus. No freeze/thaw. Grow fast roots at repot then grow small roots after some breakdown.
My friend gave me 2 large bags of akadama and I have never used it before.
It is it my mix this year so we will see.
I have not top dressed anything. Should I?

I use Akadama in my tropicals mix.
Just a greater percentage than for pines.

I don't top dress anything either.
Never had anyone whom was teaching say I should

I do remove the top layer of soil once a year if the tree hasn't been repotted and replace with fresh soil

 

[Deleted member 32750]

Its perfectly fine to use pure Akadama. as with any soil mix, you have to adjust your watering accordingly. Many seem to think you can not over water in APL mix. This is far from true, but the great thing about akadama is it will change color when it dries out and serves as an indicator of when to water again.

Per a Bjorn podcast all major bonsai nurseries in Japan use soil mixes of Akadama, Kiryu/pumice, and lava in varying ratios depending on Species, stage of development, and climate of the nursery.

for me, my go to mix for deciduous is aoki blend which is 80% akadama, 15% kiyru, 5% lava

for conifers i like a mix 60% akadama, 20% kiryu, 20% pumice. I may throw some lava in there but its not really necessary

bottom line - you need to know your trees and how much water they like.
For trees that like moisture add more akadama for trees that like to be dry add less to the mix.

Theoretically you could grow conifers in pure Akadama if you adjust your watering. Bjorn uses Aoki blend which has 80% akadama for all his trees

 

[Paradox]

It is very hard to overwater APL mix.
I had 10 straight days of rain here one spring and never had any issues from it.
My pines and juniper are in 1:1:1 APL.

 

[Deleted member 32750]

It is very hard to overwater APL mix.
I had 10 straight days of rain here one spring and never had any issues from it.
My pines and juniper are in 1:1:1 APL.

Very hard due to the low percentage of Akadama (33%) but possible.

I think the 1:1:1 APL for conifers and 2:1:1 for deciduous is a good starting point for people getting into akadama based mixes.

for me I like higher percentages of Akadama for higher Cation exchange and water holding

 

[Frozentreehugger]

Like a lot of things in bonsai, it depends.
What works in one place (ie climate), may not be the best thing in another climate. Also what works for one species may not work for another.

Also, how old were those references?
Practices may have changed over time.
All modern bonsai books recommend a mix.

The U.S. National arboretum used to use peat and sand I've been told. They no longer do.

I doubt they use pure akadama for pines. Maples maybe as they like it a bit wetter than pines.
Not sure I'd want to use pure akadama in anything that might freeze

I agree like all things . Bonsai has evolved . And I’m not suggesting to not use a mix . But mixes are mostly mentioned outside Japan . The question remains what do they use

 

[Deep Sea Diver]

My NEXT repot (OR UPPOT) will be HEAVILY lava with ...some... adadama. Not a lot. Not even the composition of the present "mix" I have been using.
Might need an aka detector to find it.
I also plan to quit hyuga. Still looking for suitable pumice.

Very Interesting. As always, your tree, your choice of media.

The best source of pumice I’ve ever used is General Pumice. Presorted, free shipping and good product. Still a bit pricey but I reprocess used media (Amazing…why doesn’t everyone?) Here’s the link.

Shop — General Pumice Products

www.generalpumice.com

Good Luck,

Cheers
DSD sends

btw ‘Boon mixes’ are merely akadama mixes used for years in Japan that were popularized in America by Boon.

 

[Paradox]

Very hard due to the low percentage of Akadama (33%) but possible.

I think the 1:1:1 APL for conifers and 2:1:1 for deciduous is a good starting point for people getting into akadama based mixes.

for me I like higher percentages of Akadama for higher Cation exchange and water holding

Yea I use 2:1:1 for deciduous trees.
I don't think there is one end all be all for ratios. If more akadama works for you in your climate, by all means use that.

You are a bit warmer in the summer than me so it makes sense. We both have high humidity in the summer. My winters are colder and it can be very rainy in winter and spring so I need to balance seasonal differences as well

 

[Dav4]

100 % akadama for my shohin maples and some of the larger ones. I will admit that my large trident and another larger palmatum really stalled on growing this year after both were re-potted in akadama and placed in very shallow pots. The trident started acting like a trident this past July but the palmatum hasn't done much since it's first mediocre spring flush. All bets are off as to the cause... could have been related to drying out last fall as both trees went crispy in October due to drought stress. I think next spring will be better.

 

[rockm]

Skip the straight Akadama and go for the Aoki soil...

 

[Colorado]

Everyone has their opinions about akadama, but the fact is this: many advanced practitioners use akadama in mixes AND as a stand-alone substrate with great success.

 

[Deep Sea Diver]

Skip the straight Akadama and go for the Aoki soil...

Dunno about such high ratio blends of akadama. But definitely worth a test.

The Aoki blend seems to run 80:18:2 Akadama:Kiryu pumice:Lava. Dunno why there’s even lava there at 2%. Maybe the pumice had lava in it?

The highest blend we use here is 3:1:1 Akadamaumice:Lava for Mountain Hemlock.

Last year Andrew Robson , a mainly maple professional out of Portland, told our club he was using 1:1 Akadamaumice for his deciduous trees.

Cheers
DSD sends

 

[Deleted member 32750]

Everyone has their opinions about akadama, but the fact is this: many advanced practitioners use akadama in mixes AND as a stand-alone substrate with great success.

this is a fact. Its all about knowing your trees, your weather, and knowing how to water according to what soil mix you are using.

 

[August44]

Skip the straight Akadama and go for the Aoki soil...

What is Aoki soil?

 

[Deleted member 32750]

What is Aoki soil?

Its a ‘professional’ bonsai soil blend that you can buy pre-mixed

Aoki Blend

Aoki Blend is currently out of stock. The next shipment of Aoki Blend is expected Summer/Fall 2025. Check out Clay King and Banzai Blend for premixes that are similar to Aoki Blend. --- Aoki Blend is an akadama-based bonsai mix made from akadama (80%), kiryu (pumice, 18%) and fuji suna (lava...

store.bonsaitonight.com

 

[rockm]

Dunno about such high ratio blends of akadama. But definitely worth a test.

The Aoki blend seems to run 80:18:2 Akadama:Kiryu pumice:Lava. Dunno why there’s even lava there at 2%. Maybe the pumice had lava in it?

The highest blend we use here is 3:1:1 Akadamaumice:Lava for Mountain Hemlock.

Last year Andrew Robson , a mainly maple professional out of Portland, told our club he was using 1:1 Akadamaumice for his deciduous trees.

Cheers
DSD sends

I've used it for a few years on a variety of trees, from Tridents to satsuki. Everything does quite well in it. It is not cheap though and it's getting harder to locate as it is bought up quickly

 

[Wulfskaar]

I got a bag of Tinyroots Akadama for my b-day. I put a couple maple seedlings in it (100% akadama) and they love it so far. It's been a few months now and the soil is still looking good.

 

[Deleted member 32750]

I got a bag of Tinyroots Akadama for my b-day. I put a couple maple seedlings in it (100% akadama) and they love it so far. It's been a few months now and the soil is still looking good.

There is a local hydroponics store near me that sells those tiny roots bags of akadama. I planted some 1 year japanese black pine seedlings in the pure akadama.. they’re rather happy and healthy too

 

[rockm]

If you're using Akadama for seedlings, you're using it wrong...and wasting your money.

All about akadama - Bonsai Tonight

Akadama is a fundamental component of bonsai soil. It is used throughout Japan as a potting medium for both bonsai and general gardening purposes. More and

bonsaitonight.com

 

[Deleted member 32750]

If you're using Akadama for seedlings, you're using it wrong...and wasting your money.

All about akadama - Bonsai Tonight

Akadama is a fundamental component of bonsai soil. It is used throughout Japan as a potting medium for both bonsai and general gardening purposes. More and

bonsaitonight.com

In my case I used it because its what I had on hand when I was transplanting.

But your comment raises a great point. What do they use for seedlings in Japan and if the answer is akadama based mixes are they using that wrong?

All I know is my batch of japanese maple seedling in akadama have much better roots and growth vs non akadama planted seedlings.

 

[rockm]

In my case I used it because its what I had on hand when I was transplanting.

But your comment raises a great point. What do they use for seedlings in Japan and if the answer is akadama based mixes are they using that wrong?

All I know is my batch of japanese maple seedling in akadama have much better roots and growth vs non akadama planted seedlings.

You've skipped past some things and are making assumptions.

You've only observed seedlings in AK for how long? A year? two? That's not long enough for the AK to break down much and start inhibiting root growth, which can take several years, or less if you're in a cold zone. You can use just about anything to start seeds as long as it stays moist and drains pretty well.