100% lavarock for JBP

[NeedlesAndLeaves]

Does anyone have experience with growing young JBP in pure lavarock?
I heard Jonas Dupuich say this in one of his videos from Eisei-en.
I use an akadama/pumice/lava/kiryu mix. It works fine, I think at least.
In summer I am happy with the wet-dry cyclus.
But during autumn and winter months the soil might be holding a bit to much moisture. Comparing it to a minimum moisture holding substrate of course.

I can imagine pure lavarock needs a “constant” watering attendance. But perhaps i am to carefull with the dry side.
Curiuous to other experiences on using pure lava rock for JBP.

Grz

 

[ZombieNick]

My sensei grows all his JBP in either straight black lava, or 65/35 Black Lava/Akadama for more developed trees. I dug one up from his yard earlier this year and have it in straight BL, seems very happy so far. I don't water any more or less than my other trees.

 

[River's Edge]

In summer I am happy with the wet-dry cyclus.
But during autumn and winter months the soil might be holding a bit to much moisture. Comparing it to a minimum moisture holding substrate of course.

I would focus on the balance of the media for the growing season and adjust the frequency of watering for fall/winter season. Or tilt the pots to assist in faster drainage and drying.
One other alternative is to reduce the akadama portion in your current mix from the normal amount. This is the approach I take living in a wet climate for fall and winter. Typical Akadama proportions range from 1/3 to 1/4 of the overall mix. I have switched to 20% of the mix and it works well for me.
As far as using straight black lava my only concern would the root formation difference in more developed and advanced tree formation. Akadama will give superior results in the long run.
Just a few thoughts to add to the topic.

 

[NeedlesAndLeaves]

I think I won’t be using pure lava myself but that is for practical reasons. But I might change the ratio of substrate for next season.

Thanks for your replies

 

[minkes]

I have my 2yr old JBP seedlings in perlite / zeolite mix. and they seems pretty happy. Next year I want to try to put few of them to lava / pine bark mix. Two weeks ago I reppoted my big Pinus Silvestris to pure lava, so I am also curious, how it will goes.

 

[Maiden69]

I can imagine pure lavarock needs a “constant” watering attendance.

This is the main thing, lava don't retain much water so you need to be on point with your watering. I don't recall Jonas mentioning that on the Eisie-en videos but he has a few blogs on Onuma's garden in Japan where he grows everything in red lava. There is also another Japanese YT channel that they grow everything while on development in pure red lava, then move to A-P-L for refinement.

Onuma's mini-sized bonsai - Bonsai Tonight

Photos from a visit to the amazing garden of Kazuo Onuma in Shizuoka, Japan.

bonsaitonight.com

Onuma's mini-bonsai growing techniques - Bonsai Tonight

Growing techniques from Kazuo Onuma for developing chojubai, shimpaku juniper, and Japanese maple.

bonsaitonight.com

 

[NeedlesAndLeaves]

This is the main thing, lava don't retain much water so you need to be on point with your watering. I don't recall Jonas mentioning that on the Eisie-en videos but he has a few blogs on Onuma's garden in Japan where he grows everything in red lava. There is also another Japanese YT channel that they grow everything while on development in pure red lava, then move to A-P-L for refinement.

Onuma's mini-sized bonsai - Bonsai Tonight

Photos from a visit to the amazing garden of Kazuo Onuma in Shizuoka, Japan.

bonsaitonight.com

Onuma's mini-bonsai growing techniques - Bonsai Tonight

Growing techniques from Kazuo Onuma for developing chojubai, shimpaku juniper, and Japanese maple.

bonsaitonight.com

Tnx for sharing
I see pure lava is used for many trees.
Since on it’s own it is not that water and nutriënt retaining, I was wondering what the benefits are to grow young material in pure lava, other than drainage and aeration.
My best guess would be encouragement of root branching?

 

[Maiden69]

I guess it is to augment the effects of the colanders he uses. Main benefit of colanders is not only air pruning, but also to provide more oxygen to the roots. By using lava and watering frequently you are not only adding more water, but as the water rushes down it pulls air into the roots.

I am using a similar method, but with particles that hold more water (nothing organic in the media), and Rootpouch bags instead of colanders. Being in Texas is not really that conductive to colanders unless you can check on your trees every few hours. I use Bonsai Block and Monto Clay from Bonsai Jack, Monto Clay is the same as turface, but properly sizes and slightly rounder which is better for the roots as it won't compact flat. I don't know what Bonsai Block would be equal to, but the tests they did says that it has similar characteristics as using black lava, but in a "rounder" less sharp particle.

This is what my substrate looks like

 

[NeedlesAndLeaves]

Never heard of it before!
Just checked on Jack’s website. Looks like a good substrate.
Unfortunatly the offer on bonsaisuplies is not that great in the Netherlands as it is in the US.

 

[SpencerI]

I am very new bonsai and I bought many pre-bonsai JBPs. Several of them were repotted in to standard one gallon pots with a lava rock, pumice, and fine bark mixture. Unfortunately these didn’t survive. The needles turned yellow and eventually they died.

Next year, I am planning to move all my JBPs to a 80/20 mix of perlite and coco coir like Bonsaify does. In the region I live, its very wet and soggy during the fall and winter and I feel that this will help.