100% pumice why not?

[Beng]

Currently I use a mix of akadama, pumice, and kiryu with a little charcoal and sphagnum mixed in. That said I've seen first hand the advanced feeder root growth that 100% pumice creates for growers out in oregon. Why wouldn't we want to use 100% pumice for all our bonsai soil now that akadama has become scarce? Some trees needing more acidic soil would need amendments, but I'm talking about all the others that don't.

Ben

 

[JudyB]

Ben,
you might be interested to read this thread, there is some discussion about pumice/lava here.

http://www.bonsaisite.com/forums/index.php?showtopic=25422&pid=223691&st=0&#entry223691

Brent is contributing to this thread so we know there is experience behind the words...

And if anyone is interested here is a thread that talks about similar issues, mostly involving turface, but does speak to other substrates as well.

http://www.bonsaisite.com/forums/index.php?showtopic=25419&hl=&fromsearch=1

 

[Poink88]

I observed same root problems that Bob described on BonsaiSiteForum...not only on pure turface but also on pure pumice, pure gravel/sand, etc. Thanks to the trees I got from our club raffle.

I disagree with Bob's theory about small air space. My theory is that they are all great but not when 100% pure. The mix need inorganic IMHO...OR means for the fert to adhere to the mix and retain water. This is the reason I am very interested on humic acid right now (thanks Smoke!!!). I also think the super fast draining substrate kills the roots trying to grow there...what is left are the ones on top (due to some organics deposited by leaves etc.) and along the sides & bottom of the pot...where water stay longer. Problem is, once the roots colonized the area, there will be more water retained (vicious cycle) causing rot.

This is just MY theory and I am actually proceeding with my mix with this in mind. So far so good with 50% Turface and 50% chopped bark (neither are sifted and mixed straight from the bags). Sometimes this mix is further amended with some chopped moss too.

Again, I am a newbie who does things a bit differently so please take it into account. I also only have pre-bonsai in larger training pots, though I do not see myself changing my mix when they move to the bonsai pots (for now at least).

 

[Dav4]

I'll preface my comments by stating that I havn't read the linked thread. Anyway, I've used turface(typically mixed with lava and grit) for close to 14 years as a soil component and have come to the conclusion that it has its drawbacks, particularly in large pots. It seems to compact somewhat and form a layer of soil on the bottom of the pot that remains extremely wet, which has, in turn, impacted root growth. At least for my larger junipers and pines, I'll be significantly reducing the portion of turface added, and will replace it with punice (Drystall). I think turface in smaller pots is fine as they dry out faster. My .02

 

[mat]

Dario, where do you get the chopped bark?

 

[Poink88]

Dario, where do you get the chopped bark?

From Lowes. It is Hapi-Gro Landscaper's Mix and sells for around $2.50 per 2 CF bag. They have pine bark mulch as well but those are bigger chunks and I won't recommend them.

 

[coh]

I have one tree growing in 100% pumice, a collected engelmann spruce. I got it that way and when I repotted last year, I continued with the 100% pumice. It was more of a slip-potting, I didn't really get into the root mass - but from what I could tell, the roots looked pretty darn good and the tree seems very healthy. I think it was collected about 4 years ago and has been in the pumice since.

Pumice is not easy to find in the eastern states, and the "dry-stall" isn't available everywhere. Up here (western NY), I looked for it and several places said "yeah, we can get that". After further discussion I found out that they could get something called "stall-dry", which they assumed was the same thing...but it was NOT. I think that stuff was a soft clay product more like some kitty litters. So make sure you're getting the right stuff.

I don't use 100% turface, but have acquired some plants that were potted in mixes that were close to that. When I repotted the lower layers seemed pretty wet (especially in deeper pots, or nursery pots). I've always thought it might be that the particle sizes of turface were a little smaller than what would be ideal. However, I do know of a number of growers who have had great success using mixes that are almost pure turface. Might work better in shallower pots?

Chris

 

[yenling83]

Great Question! IMO If it's really hard for you to find Akadama then yes experiment with other mixes.
Here's prob my favorite article on soil by Peter Tea which I believe will answer your question:

http://peterteabonsai.wordpress.com/2012/05/15/repotting-a-beast/

I use 100% pumice for my collected trees and this promotes good root growth. I don't know about mixing sphagnum moss in with your mix, seems a bit counter productive. Sphagnum is great to put on the soil surface-here's a fantastic article by Owen Reich on the subject:

http://yamadoriforsale.com/2012/12/08/mizu-goke-and-the-benefits-to-bonsai-by-owen-reich/

While others may disagree, I tend to try and follow/emanate what the top Bonsai nursery’s in Japan are currently doing. The main mixes I have seen, seem to be made up of the following ingredients- akadama, pumice, lava and river sand(basically just grit) in various ratios for most trees except azaleas.

Cool Post about River Sand:
http://bonsaitonight.com/?s=river+sand

So far i've been able to find akadama in California with no problems, but it may be different in Oregon. Go to any of the major shows in Nor Cal and you can find bags of akadama or Clay King(pre mixed high quality Akadama, pumice and lava). You should find out where Michael Haggedorn and Ryan Neil get their akadama.

Not sure if you learn from/take lessons with any of the Bonsai artists up there. But, it's been a large benefit for me to use the same soil as my teacher. That way, when discussing a trees health there is a foundation to start from and you can go from there.
Another benefit of Akadama:
-Quote from Peter Tea, "Akadama is an interesting soil because it evolves with the root system. At first, it holds only so much water, then as the tree grows more roots and the akadama starts to break down, it holds even more water for all the new roots."

For my trees in training/growing out-besides my trees that were recently collected i'm experimenting with a roughly a 60% pumice mix, 38% lava and 2% charcoal mix and have had very good results. I have experimented with turface and bark in the past and like the pumice/lava mix much better. I also plan to try using river sand(I’m using small graded crushed granite) in various amounts. I would use akadama in my mix for growing trees out, but it's just too expensive. I can purchase Lava, Pumice & crushed granite by the yard for very inexpensive.

 

[mat]

From Lowes. It is Hapi-Gro Landscaper's Mix and sells for around $2.50 per 2 CF bag. They have pine bark mulch as well but those are bigger chunks and I won't recommend them.

I knew you were going to say that. They don't carry it down here. I checked every store within a few hours drive. Must be a regional thing.

 

[Poink88]

I knew you were going to say that. They don't carry it down here. I checked every store within a few hours drive. Must be a regional thing.

Could be. My local bonsai club actually announced/reminded us around November to buy them, dry and start sifting in preparation for the spring repotting season LOL.

 

[Bill S]

I knew you were going to say that. They don't carry it down here. I checked every store within a few hours drive. Must be a regional thing.

Most "stores' like Lowes etc. will ship from one store to another without cost, try that, hopefully they can have it shipped to the store near you.

 

[mcpesq817]

I'll preface my comments by stating that I havn't read the linked thread. Anyway, I've used turface(typically mixed with lava and grit) for close to 14 years as a soil component and have come to the conclusion that it has its drawbacks, particularly in large pots. It seems to compact somewhat and form a layer of soil on the bottom of the pot that remains extremely wet, which has, in turn, impacted root growth. At least for my larger junipers and pines, I'll be significantly reducing the portion of turface added, and will replace it with punice (Drystall). I think turface in smaller pots is fine as they dry out faster. My .02

I agree 100% with the above, having had similar experience. I would be careful using fertilizer cakes with 100% turface mixes as you can get some pretty bad crusting at the soil line leading to dry spots.

I will say, however, that you can really develop great root systems on seedlings using 100% turface. I've also had very good results using 100% turface to backfill pots holding collected material such as yews and boxwoods.

 

[Brent]

"Akadama is an interesting soil because it evolves with the root system. At first, it holds only so much water, then as the tree grows more roots and the akadama starts to break down, it holds even more water for all the new roots."

This is a very interesting quote. I have said EXACTLY the same thing about my mix which contains bark and perlite. I use only the freshest uncomposted bark I can find to ensure longevity. This fresh bark and chunky perlite mix contains tons of air and has fantastic drainage, water goes straight through. It is ideal for seedlings and transplants that don't need a lot of water but do need frequent water. It is impossible for it to stay too wet. After just a couple of months I notice that the mix begins to hold more water (from the weight of the pots) which coincides with the growth of the plant, so there is a larger reservoir when you need it. This is the only other quote I have seen on this phenomenon. I think this is the result of both the beginning of the breakdown of the bark and the packing/settling of the particles.

Brent
EvergreenGardenworks.com

 

[Brian Van Fleet]

Dav4: are you using a drainage layer and still finding this to be the case?

Mat: if you have Evergreen brand at Lowe's/Home Depot, their "Soil Conditioner" is chopped pine bark and works excellent, barely needs to be screened. A 3 CF bag is about $4.00.

 

[Dav4]

Dav4: are you using a drainage layer and still finding this to be the case?

QUOTE]
I've never used a drainage layer, but have contemplated using one in my larger pots. In any event, I think the addition of pumice to my current mix is going to help. My plan is to reduce the turface by half, along with the grit, and replace it with mostly pumice and a bit more lava.

 

[Poink88]

Anyone tried putting a drainage wick instead? (wick dangled through the drain holes to eliminate pooled water inside)

 

[wireme]

Hi Brent, can you tell us what size of bark and perlite particles you use?

 

[mat]

Mat: if you have Evergreen brand at Lowe's/Home Depot, their "Soil Conditioner" is chopped pine bark and works excellent, barely needs to be screened. A 3 CF bag is about $4.00.

I've looked for any sort of soil conditioner - none here. Maybe our soil doesn't need that sort of conditioning? I'll make some calls now to check on the Evergreen brand name. Thanks.

Most "stores' like Lowes etc. will ship from one store to another without cost, try that, hopefully they can have it shipped to the store near you.

I've talked to them a couple of times. Nobody stocks it near enough for them to put it on a truck for here. Thanks for the suggestion though.

I'm thinking of just ordering some on-line and biting the bullet to pay shipping.

 

[Brian Van Fleet]

I've never used a drainage layer, but have contemplated using one in my larger pots. In any event, I think the addition of pumice to my current mix is going to help. My plan is to reduce the turface by half, along with the grit, and replace it with mostly pumice and a bit more lava.

I always use a drainage layer, usually gravel, sometimes lava or river rock, and have never experienced turface settling to the bottom like that. I actually striate from coarse to fine at the top, but that's a whole 'nother can of worms!

 

[Kirk]

"Akadama is an interesting soil because it evolves with the root system. At first, it holds only so much water, then as the tree grows more roots and the akadama starts to break down, it holds even more water for all the new roots."

This is a very interesting quote. I have said EXACTLY the same thing about my mix which contains bark and perlite. I use only the freshest uncomposted bark I can find to ensure longevity. This fresh bark and chunky perlite mix contains tons of air and has fantastic drainage, water goes straight through. It is ideal for seedlings and transplants that don't need a lot of water but do need frequent water. It is impossible for it to stay too wet. After just a couple of months I notice that the mix begins to hold more water (from the weight of the pots) which coincides with the growth of the plant, so there is a larger reservoir when you need it. This is the only other quote I have seen on this phenomenon. I think this is the result of both the beginning of the breakdown of the bark and the packing/settling of the particles.

Brent
EvergreenGardenworks.com

That is great to know. I've been using the same bark and perlite combination as my general nursery mix. I will also incorporate PermaTill when available. It's also sold as "VoleBloc". It's a small particle of porous slate with visible air pockets, about the size of medium akadama. I like the weight it adds to the pots and keeps plastic nursery containers from tipping as the tree grows. In the Atlanta area, Ace Hardware carries it along with a great pine bark soil amendment called "Jolly Gardener". It has great particle size and isn't decomposed like Nature's Helper.

Kirk