AusBonsai

Recently, a good friend of mine has given me the opportunity to work on a mature pine that she has had in her collection for quite some time.

Over the last few weeks I have noticed that when watering, the water often pools on the surface and runs off the edge of the pot rather than penetrating deep into the pot, and wetting the entire rootball.

In light of this, today I decided it was time to perform Autumn Soji on the tree. 'Soji' is 'to clean' in Japanese. I use the term in reference to the top 2-3cm of the soil in the pot.

Before Soji: First thing we do is get out the bent nose tweezers and rake the top of the root ball outwards. That it from the centre of the pot to the rim. (I just realised i didn't capture pictures of this the reason that we rake outwards, is that it only damages the crossing and unattractive roots. It should also be note that if there are any small roots crossing or growing upward etc this is a great opportunity to cut them off. Large roots are cut at repotting.

Post Soji:

To help the water penetrate the rootball more thoroughly I 'cored' the rootball: Next, I added a layer of Osmocote: Then sieved the new 'top soil' (Akadama/Diatomite/Zeolite with a little charcoal and granite added, it would be 50:50 Akadama/Pumice but I have run out and need to get back to Sydney to pick up some more):

Next up, adding the new soil: After Soji: Fertilizer replaced: Watered thoroughly:

Interesting technique. Was the stuff you removed from your previous mix used throughout the rootball or did you have two mixes present in the pot at once? Where do you purchase pumice in Sydney?

Thanks,
Joel

Hi Joel,

The 'old' top layer of soil was a mix of brickdust as a dressing, potting mix/gravel/Zeolite/brickdust. This is not the mix that I use, but what the pine was in (still is in except the top 2-3cms)

I use Akadama/Pumice/Charcoal/Granite, a larger size for pines, smaller for Deciduous, and smaller still for the top soil (this work).

I get Pumice from:
http://www.australianperlite.com/pumice ... ulture.htm

This year I will be getting a much larger amount than last year.

A link to a student of Boon, performing soji in Summer:
http://bonsaitonight.com/2010/08/27/summer-soji/

H3ey Joel you beat me to it
I was going to ask where to get pumice as I have never been able to find it

Thanks Scott

Ken

Group buy...it is a lot cheaper if we buy a large bag and distribute it out, Im happy to buy a lot!

Hey scott, what are those 3 white chunks on top of the soil that look like turkish delight ???

Scott Roxburgh wrote:Group buy...it is a lot cheaper if we buy a large bag and distribute it out, Im happy to buy a lot!

How Much is it? They did not have prices on the website

Jester wrote:Hey scott, what are those 3 white chunks on top of the soil that look like turkish delight ???

Fertiliser - Tea bags filled with soybean meal and blood and bone.

kcpoole wrote:

Scott Roxburgh wrote:Group buy...it is a lot cheaper if we buy a large bag and distribute it out, Im happy to buy a lot!

How Much is it? They did not have prices on the website

I cant remember prices but I'll call them to check.

Scott, could you possibly bring a sample of the pumice to the May meeting? It looks very interesting....

Many thanks,

Gavin

Scott,

Now you've done this, will you still plan to repot in Spring or will this extend the time until the next repot?

Cheers

nitram72 wrote:Scott,

Now you've done this, will you still plan to repot in Spring or will this extend the time until the next repot?

Cheers

Repotting can still be done in spring.

This work is generally done to remove the build up of organic fertiliser waste on the soil surface, but I have used it in this case to increase the drainage of the tree.

I may remove a small section of the existing soil this year and slowly replace the entire rootball over the next few years...

GavinG wrote:Scott, could you possibly bring a sample of the pumice to the May meeting? It looks very interesting....

Many thanks,

Gavin

What you see above isn't pumice...I haven't got any left.

I'll try and sift some out of one of my pots and bring it along...it may be a small amount though.

kcpoole wrote:

Scott Roxburgh wrote:Group buy...it is a lot cheaper if we buy a large bag and distribute it out, Im happy to buy a lot!

How Much is it? They did not have prices on the website

$19 per 20kg bag or $14.85/bag if you buy a pallet of 50 bags.