Doing the growing medium thing a little bit differently.

My growing medium consist of about one third each of good garden loam, sifted compost(the roughs sifted out) and 1mm-3/4mm crusher run(dolomite). I get very good growth with this medium and I have rarely lost a tree - I can remember one mame Celtis that dried out two winters ago and it died.

This is how the medium looks after a repot:



In summer one watering a day is not enough for fast growing trees so I am forced to mulch my trees. Last year I used horse stable bedding(straw and horse manure half rotted) but this year I can't get it. This year I am using half rotted compost and fresh cow manure:

In the following pic you can see the dry cow manure, the dry compost and the water soaked mix of the two:



I soak the mix so it will take up water easier when I water and also to let the fines settle on the bottom of the container. The mulch is then spread on the surface of the growing medium as thick as possible:



The above picture is how the Acacia looks ten days after budding out.

My climatic conditions differ from others and I do have many years of experience in growing all kinds of plants- this kind of growing medium and mulch works for me.

The most important thing to me is that the planting medium and mulch must be dried out before using it - earthworms becomes giants in bonsai pots!

Anyone else using a similar mix?

Any comments welcome.

Lennard

I bet this must get a bit stinky!???

Hi Lennard,
very interesting.
what do u mean by "I get very good growth" ? can u give me please any measure ...

thx
Efi

Your mix would not work in my climate (The Netherlands) of wet and cold. I use a inorganic free draining mix of equal parts of Akadama, grit (both sharp and round) and Kiryu.
But if it works for you..... In the end that's all that's important.

Hi Lennard

Thanks for putting your foot in it, I also cannot get away with the growing mediums most seem to use.

I've moved away from loam, and I grow fruit trees (temporary measure...long story  ) in just slightly larger containers in much the same mix as I now use for my bonsai.
One thing I've noticed, the fruit do not taste as they should, I assume this shows up deficiencies in the growing medium.

Cheers
Gerhard

Gerhard,

I admire your honesty, most folk would never admit the bit about the fruit, and - aside - most folk would never come back and say a tree died.
Thank you.
Khaimraj

Hi Khaimraj  

Correction - my kumquats tasted great, until I killed the tree!   Less than serious but 100% true

FWIW, most of the fruit trees will go in the ground as soon as I have a place for them, it's a mobile collection, and bonsai techniques scaled up a bit is useful for keeping ANY potted plant/tree healthy......not worried about what the fruit taste like now.
What does happen is I get a liking for a plant, like what has happened with an apricot now, so I'm going to air-layer it to get rid of the rootstock below the graft.

Lennard - thanks, I'll try your method.......
If you don't mind me asking, (roughly) what part of SA are you?

Tuesday & Wednesday was just slightly hotter (late 20's early 30's) and my swimming-pool-filter-sand-mix dried out in 2 trees that are growing like crazy.
It gets up to 45C (low humidity) here, I cannot comprehend how a tree could survive that planted in pure, free draining inorganic mix without getting watered at least once during the day.

Potting mixes, there is a unique one for just about every grower. If you are getting good results, then that is the one to use. You have a much warmer climate than most north american and european growers. I like that you are getting organic nutrients from the manure. Keep an eye on how well the pots drain. If you notice them taking too long to dry out, then it might be time to repot.

When I first read the post I though "dolomite, that is very alkaline, most tree species won't like it". Then I realized, you are in a sub-tropical climate, with only a brief cool spell in winter, at least brief compared to central and northern USA, where I live.

Dolomite at temperatures above 60 F or 18 C is virtually insoluble. At warm temperatures it is almost as inert as granite, so in your climate it acts more as a neutral media. And when the organic acids from the manure hit the dolomite even in warm temps, the dolomite neutralizes the acids without necessarily raising the pH of your mix. For your climate, your mix sounds like it would be excellent. Well done.

DangerousBry wrote:I bet this must get a bit stinky!???

I should have rather named the manure fresh dried cow manure. In the state I use it it does not stink at all. I also use it as a lawn dressing in spring.

Last spring I used the horse stable bedding. Before spreading that I spread some chicken manure pellets on the surface - that was not smelling nice!

Lennard

efishn wrote:
what do u mean by "I get very good growth" ? can u give me please any measure ...
Efi

The growths on the Acacia in ten days is about 15cm - 20cm long. The mentioned tree's canopy is "highly ramified"? On Acacia with less twiggy growth the growths are even longer. On Trident Maples budding out about three weeks ago the growths are about 30cmm long already.

Getting this good growth rate is not only about the mulch releasing nutrients every time I water - my trees get sunlight the whole day and temperatures here hoover around 30 degrees Celcius for 6 months of the year. This gives me a growing season of almost 9 months when it comes to a species like Celtis africana- this species can be defoliated easily  three to four times in this time frame.

Still have to figure out a better growing medium for my Ficus - not happy with their growth rate.

I am very blessed with climatic conditions here in Rustenburg South Africa - one can have an alright looking tree within three to four years from the dig/chop.

Lennard

arihato wrote:Your mix would not work in my climate (The Netherlands) of wet and cold. I use a inorganic free draining mix of equal parts of Akadama, grit (both sharp and round) and Kiryu.
But if it works for you..... In the end that's all that's important.

Yes, in a wet climate you will have problems with my mix and mulch - It rained here about 6 months ago and in summer we get mainly thunderstorms with heavy rains.

Lennard

GerhardGerber wrote:Hi Lennard

Thanks for putting your foot in it, I also cannot get away with the growing mediums most seem to use.

I've moved away from loam, and I grow fruit trees (temporary measure...long story  ) in just slightly larger containers in much the same mix as I now use for my bonsai.
One thing I've noticed, the fruit do not taste as they should, I assume this shows up deficiencies in the growing medium.

Cheers
Gerhard

Most of the inorganic growing mediums are not available here and if so they are very expensive. I have a lot of trees in different stages - can not afford to buy the growing medium.

Lennard

Khaimraj Seepersad wrote:Gerhard,

I admire your honesty, most folk would never admit the bit about the fruit, and - aside - most folk would never come back and say a tree died.
Thank you.
Khaimraj

The one that died I am very sad about - it would have been a nice little tree by now!

I won a first prize by popular vote at a regional meeting with it - a weekend away at an expensive lodge!

Lennard

Leo Schordje wrote:e. Keep an eye on how well the pots drain. If you notice them taking too long to dry out, then it might be time to repot.

Well done.

At the end of the growing season I do lift all the trees in bonsai pots and spread a little gravel on the bottom of the pots. This helps with drainage in winter.

Strangely enough the shallowest bonsai pots have the drainage problems in winter.

Thanks for the positive reply.

Lennard

Hi Lennard

I'm in PE, not as hot as where you are, and I also use the crusher run.  6mm clean stone they call it at the quarry and I mix it with outdoor potting soil from a local nursery.  My mix is between 20% and 40% potting soil and the rest the clean stone - by volume.  For the trees that dry out quickly, I use up to 40% potting soil.  The trees love it!

I'm experimenting with mulching to help deal with the hot "berg" winds that come from the karoo.

Thanks for the info

You know guys,

I have been looking for a common denominator to this soil ingredient situation.
At some point we will work out a mix that works world wide and the information will be easy to pass on to newbees.

Something like -

[1] Low humidity - Hot sun
[2] High humidity - Hot sun

Compost at x % with inorganic to handle high humidity or low humidity.

I chose compost because it is easy to make.

Presently I am testing glass marbles and compost with a tree, just to see if the ball bearing effect will work here, and if all the tree needs is the compost to feed on. If it needs more, I can sift on more compost.

What we do in oil painting is lower the factors to get folk to just paint and paint archivally.

What I would like to do to bonsai is just get folk to grow trees instinctively and spend all of their time on Designs.

If my idea with the marbles works, it would just be a case of altering the % of compost to hold more or less moisture, and actively feed the tree.
Well that's my gift to the world of Bonsai.
Later,
Khaimraj

Hi Lennard. I stayed in Brits before I moved to NZ. I know that climate to well. Water evaporates before your eyes.
I have the complete opposite in my climate in Wellington. It rains all winter long. No need to water at all. I use a 1-1-1 mix of composted pine bark, pumice and granite grit. All sifted to the same size (3-5mm) The bark is mostly bigger but I make do with it. The water runs through but it also retains an amazing amount of moisture. I use a dowel stick in the substrate to indicate when to water. I don't use any compost or manure at all. I flush and feed (Dyna Gro) with every watering but at half the strength. In summer it can be a problem but the substrate really does retain enough for about 2-3 days .....  
I imported some Celtis, Acacia Xantephloea, Erythrina ect seeds and some have germinated already. I can see that I will be having my hands full come winter with this wet weather but I will give it a good go. Soil is Everything...!!!