Growing Medium Test - Sargents Juniper

[kcpoole]

I am interested in alternative growing mediums, and have developed my own Mix of Diatomite and Zeolite as outlined here viewtopic.php?f=12&t=40
See also this thread for info on Akadama and Kanuma viewtopic.php?f=20&t=1833

In Order to get some hard facts as to whether it is useful or not, and the relative performance of the soils, I am conducting some long term tests with several different plant species, and soil types.
I will have 3 of each variety, and they will each be in different soil type and subjected the same Watering, Fertilising and general care / maintenance.
Over several years I should be able to identify trends and performance of each soil type.

The trees will all be photographed in the same order from left to right, sort of Alphabetically.
Akadama Mix ( or Kanuma for Azaleas), Diaomite / Zeolite Mix, and last Ray Nescis own Bonsai soil as a control.

I have purchased 3 of Ray Nesci starters trees and have potted them this weekend into 75 mm Orchid pots

This thread will be Sargents Juniper

Please note I have not go the Akadama as yet, and when i do i will repot the one on the left, Currently it is in Rays mix

Ken

[kcpoole]

A link to each relevant thread so I can find them easily

Flowering Cherry thread - viewtopic.php?f=12&t=1877
Sargent Juniper thread - viewtopic.php?f=12&t=1878
Zelcova Serrata thread - viewtopic.php?f=12&t=1879

[Jow]

cant wait to see the results of this.. even if i have to wait a few years

[kcpoole]

Update each tree has leafed out at the same time and looks like they are Growing well
Azalea tests viewtopic.php?f=12&t=2056

I will repot the left hand tree into Akadama Tomorrow

[kcpoole]

Wile hecking all my trees today, I noticed these Junis were all going slow so pulled one from the pot and saw the tiny pts were starting to get too full of roots. They wodu not do too well later in summer so decided to to a repot today.
I minimised the disturbance to the roots and oly trimmed where they were starting to circle the pot.

the observations are
Akadama - Least amount of roots in the pot, and second amount of Growth on the tree
Rays Mix - Probably most roots in the pot ( started to get the matted roots on the inside of the pot), and least amount of growth on the tree
Diatomite - Second amount of root ( only a little less then rays mix), and by far the most growth up top.

When repotting, I had to trim the roots from the edge of the pot just under the soil level with rays mix. Diatomite there was lees rooots around the edge of the pot, but the bottom of the pot had heaps where rays had not much around the drain holes.
Akadama I did not have to root trim at all. Just sip potted.

The tree above the soil the diatomite one is quite taller and "fuller' than the others. The Rays mix one was also quite bushy, but much shorter. Akadama was quite a bit smaller
the trunk thickness also matches the growth show above

they are all now back on the bench for another year.

ps
they all sit next to a group of 3 test Casuarinas. As a comparison, I can barely pick any difference between the 3 of those

Kne

[kcpoole]

An update today
Seems like the tree in my Diatomite mix has a little more "bulk" followed by Ray and then Akadama

From my numerous test the over the last 2 years the Akadama does not surprise me. I will use the remainder I have for ongoing tests, but will not bother buying any more. I consider its performance on several different types of trees and conditions and there are fare better substrates to use

till next time

I will add a note here that my tests on Casuarinas from seed are progressing too. I have 2 different sets, 1 out in full sun and 1 in part shade under gum trees.
They were germinated 2 years ago and are all in the same size 6 inch pots
Both seem to correlate that there is little to pick between the performance of the 3 soil re growth rates
When its hot, akadama dries fastest then Rays then Diatomite. if they do dry out, the diatomite is easiest to rewet and the plant to recover.

Ken

[Boics]

Currently very interested in soil mixes and preferences.
Been reading a heap on the forums and elsewhere.

Any update here Ken?

Shame about the cherry and Zelkova - be interested in how they are going regardless.
Or any others?

Cheers,

[kcpoole]

Hi Boics
I recently Repotted all 3 of the junipers from the test mixes into my normal diatomite mix after the last winter. The three trees were in the test mixes for 2 years.

The final results were the mostly the same as the previous update, excepts that the Control tree in Rays mix had caught up and possibly surpassed the Diatomite one. I t certainly had more roots in the pot, but not by much.

From most of my testing on all the trees, Daitomite or Rays own mix was the best performing, but I get a pot full of Curl grubs when using Rays mix so that precludes me from using it. Another reason not to use it is that if it does dry out, it is very difficult to rewet.

The Akadama in every one of my test species was a waste of time and money. Its water holding ability is very poor compared to the others, and the propensity to dry out faster than either of the others in Sydney is no good. The trees regularly drooped due to heat and lack of water where the others were fine. when i repotted, the Akadama was still firm and not soft and mushy, so it longevity is quite good. At $25 for a 10L or so bag, it a far too expensive anyway.

Diatomite does have a few issues, mainly the Green scum that seems to want to appear on the surface after fertilizing. Particularly i winter where the surface stays wetter for longer. My solution is to just scrape off the top layer and replace it with fresh. The Green stained stuff just dry out, wash it and then reuse.
After a year, the surface tends to become a little packed down. and again the solution is to just scrape or rake the surface then refresh the top layer.

if you do not want to go the total inorganic mix, then add up to 80% diatomite to whatever you want to use as suits your own environment.

Ken

[kcpoole]

the only Zelcova I had survive was the one in Diatomite and it is now in the ground, and all the Cherries did not survive. I have new ones on the bench and they are all in Diatomite.
Casuarina is also in Diatomite along with the new ones I germinated this year.

Ken

[Damian Bee]

Mt Sylvia?

[Scott Roxburgh]

I am pretty sure Ken has used Mt Sylvia for a while now, after being unable to find Maidenwell.

Interesting results, it seems that Diatomite is not best suited to your watering schedule and environment Ken. I did a bit of testing along the same lines as you and found that both Akadama & Diatomite used 100% did not work for me.

I think cutting any 100% soil mix with something with different properties yields better results.

[Dario]

Hi Ken, regarding the akadama it obviously does not suit your climate in regards to water retention and it is expensive.
However I was thinking from your growth results that a mix with higher levels of akadama may be suited to a well developed tree that is in the refinement stage.
A tree in this situation would likely be in the same pot for at least a few years if not longer before it is repotted again, and as you noted the hard akadama did not break down.
Whilst you do want a tree in this situation (a very developed tree) to grow and be healthy, you may not want it to grow as prolifically as it may do in the other soil mixes you mentioned, keeping in mind that you may also wish to maintain the tree in question in a root bound state to a certain degree.
So increasing the amount of akadama dependent on the trees stage of refinement and its requirements may be a good thing in terms of growth and repotting frequency. The price issue may cancel itself out if you are not repotting a refined tree as regularly compared to other soil mixes. And you can of course adjust the percentage of akadama in the mix and this may also ease the watering issues compared with 100% usage of akadama.
I have no highly developed trees in the refinement stage, nor do I have any experience with akadama so this is pure speculation on my part.
I only mention it as I was told by experienced European growers of very developed quercus suber(cork oak) bonsai to increase the percentage of kanuma in the mix dependent on how refined the tree is.
They did not give a reason as to why (as it was only mentioned in passing while addressing other issues related to cork oak bonsai), but they did stress that it had to do with the stage that the tree was at, and to only use a maximum of 20% in a developing tree that requires growth.They substitute akadama for kanuma with cork oak as the kanuma is more acidic, and cork oak like a slightly acidic soil (I opted for a substitute for the acidic component as kanuma was harder to source).
I understand that your comparisons were for stock that required lots of growth etc, but what are your thoughts about using more akadama in the mix with refined bonsai?...or would you still avoid it and use something else?
Sorry that this is a little off topic Ken.
Cheers, Dario.

[Scott Roxburgh]

Interesting thoughts Dario, I can't say that I have experienced Akadama limiting the growth in my trees

[Dario]

Hi Scott, yeah just speculating as I don't have any experience with akadama or keeping refined bonsai...just going off the low growth rate in Ken's tests when he used 100% akadama in his pre bonsai stock when compared to the other mixes he used.
Also he showed less growth when he used 100% kanuma in the azalea tests too.
That, and an assumption I made based on what a European grower mentioned to me in passing.
So it doesn't surprise me if I am way off the mark
Cheers, Dario.
PS my jbp seeds have sprouted and are doing well at this stage so thanks Scott
Also Scott, what percentage of your mix is akadama?

[kcpoole]

Mt Sylvia?

Yep, Have used it for about 5 years now
Ken