I saw some jade plants at a nursery yesterday and they looked trainable as bonsai. They were in 1 gallon pots (~3.79 liters) and in potting soil. If I were to train one as bonsai, would it be okay to change the medium from potting mix to akadama? Would it cause a shock?

Succulents are major aspect of my horticultural life, though I am new to bonsai, I'm an old hat with plants in general.

Crassula ovata only requires that its soil drain rapidly and really has no pH preference though if its soil is too acidic or too alkaline, it will inhibit nutrient uptake, not that succulents in general need a lot of feeding, though beware of excess nitrogen. It makes them grow really leggy.

Akadama will likely make the soil too acidic.

Really, the best soil is one specifically for cactus & succulents. Any commercial soil for them will do, whether it's Bonsai Jack or Miracle Gro.

And remember, Jade has really shallow roots so it can easily topple so pack the soil firmly, but not like gunpowder.

Enjoy!

I dont think akadama is acidic.

For my jades I use a mix of 50% cactii soil and 50% pumice. Repotting every 3-4 years. Pumice is sifted out and reused.

Correct, akadama itself is not acidic but it's ability to rip certain ions out of solution is what makes it make water/soil acidic.

Akadama, like many similar clay products, has an extremely high surface area which makes it adsorbtive. That's not a typo. Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This is called having a high cation exchange capacity or CEC. A cation is an ion with a positive charge and an anion is an ion with a negative charge.

Calcined (high fired) clay products tend to remove +2 ions. Two of those in particular are calcium and magnesium. Ca and Mg salts are what make your water or soil hard & basic (sodium, too) if there's a lot of them, or soft & acidic if there's very little of them. Akadama has this affinity and can make your soil acidic but in a good way.

Succulents, however, have different needs. Because they evolved to get a lot of sun as well as numerous other measures against extremes of heat & drought, they need more of these elements than most temperate plants do. Mg for making chlorophyll and Ca for opening and closing their stomas, the little pores on the leaf that let in/let out water vapor, CO2 & O2. Succulents pack a lot of Mg in themselves because they've evolved curved surfaces to capture more light without cooking themselves but that means more chlorophyll which means more magnesium.

Also, succulents have a weird way of photosynthesizing: They do it at night! Read up on CAM or crassulacean acid metabolism. It's quite incredible! To do this, they basically hold their breath, that is, they keep their stoma (pores) shut all day then open them up at night and begin the process of making starch. This requires as much calcium as they can get.

Anything you do to remove these two precious elements in particular will make the surrounding soil/water more acidic which includes akadama, though it is itself not acidic it certainly does have the capacity to make soil/water more acidic. Not good for vast majority of succulents.

Interesting. Did you know that both ca and mg is totally ph neutral and dont affect ph whatsoever?

The misconception that ca and mg affects ph is quite common because they are in abundance in high ph water. But just study up on ph and you will see that it is a measurement of free H ions in the water (negative logaritm). Only H and O ions can affect ph. If there are none of it in whatever ion one are adding or taking out it is ph neutral.

Tropfrog wrote:

Interesting. Did you know that both ca and mg is totally ph neutral and dont affect ph whatsoever?

The misconception that ca and mg affects pH is quite common because they are in abundance in high ph water. But just study up on ph and you will see that it is a measurement of free H ions in the water (negative logaritm). Only H and O ions can affect ph. If there are none of it in whatever ion one are adding or taking out it is ph neutral.

That is mostly correct. How, do you think these ions exist? They get there as salts or acids or other radicals. Remember, water is terrible at keeping gas in solution, like O2 or CO2. A simple splash would release them and now you have a wild pH swing but that doesn't happen, does it? Those minerals and acids contribute to the process providing those hydrogen & oxygen ions as the whole of the solution equilibrates from moment to moment. This is called buffering, in general. Yes, air does have an effect but it isn't the entire effect.

I have studied up, in a very practical & applied way on pH as an advanced aquarium keeper for 40 years. This is what the non-scientist without a lab does to understand and correct conditions for their animals & plants and it has worked for the whole of the hobby for a couple of centuries now. This is the knowledge in it's most useful form for the majority of folks just trying to understand & help their plants and animals live. No need to be a full time chemist and split highly technical hairs that contribute little to the overall success of the new hobbyist unless one values pedantry over practical advice and general assistance. I firmly believe in my heart of hearts that you certainly do not value that.

Wow 40 years of keeping fish. Not bad, I am only on 38 .

I am not the one starting to talk advanced chemistry. But the one that does needs to get it right. Ca and mg have no affect on ph whatsoever in fresh water, period.

Your theory about akadama gets acidic by time needs to be checked. Why do people add acidifying materials mixed up with akadama in azaleas?

In any case a very interesting theory. I have a tree in 100% akadama that needs repotting in spring. I will try to remember to test that theory then.

And you will observe this because your akadama scavenged some of those ions used to help buffer. It'll only be very slight, not like your soil turned to battery acid and no doubt the non-succulent trees your growing need it that way because there needs a different from succulent needs.

Good talk. I knew I liked you.

By the way, which aquarium forums do you frequent? I use this same user ID on Aquatic Plant Central. A lot of my experiments and builds are on there.

Way off topic now:).

I have my jades in 50% cactii soil and 50% pumice. Before that I had them in 100% cactii soil. I think the new mix is better in my conditions. Before I changed I lost a few by rotting in winter. 5 degrees and more humidity than I would like.

Btw: I just signed up on apc and subscribed to your Youtube channel.

So succulents won’t tolerate slight acidity? Then what types of plants do well in akadama? Just conifers? I know conifers like slightly acidic mediums.