Anil

Absolutely, it is well documented that good container mixes should have
about 25% porosity (air space by volume). There are even simple tests
you can conduct to measure it. I could post one if anyone is interested.

The rate at which the water drains out is only an indication of
aeration. The situation is this: Water will drain from a pot of soil
until the lowest possible level of saturated soil is reached. No more
water will drain out, EVER. The height of this column of saturated soil
in the bottom of pot depends upon the nature of the soil, but mostly by
the particle size. The finer the soil, the higher the column, and thus
the greater the volume of saturated soil (and total volume of water)
retained after drainage.

Further removal of water is accomplished by transpiration of the plant
(water is absorbed by the roots and transported to the leaves). It may
not be obvious, but this is the greatest factor in removing water from
the soil, evaporation is the secondary factor.

You can do some simple experiments to test this. Saturate a common
sponge with water and place it flat on your hand until it stops
draining. Then tip it vertically, more water will drain. This is because
you have increased the height of the saturated column. It will continue
to drain until the column height is the same as the flat sponge. From
this experiment you can see that the shape of the pot will also affect
the amount of water retained. A tall pot will retain LESS water than a
low flat pot of the same volume with the same soil.

Brent
EvergreenGardenworks.com


Anil Kaushik wrote:

Brent

Thank you for the comprehensive reply. At last I got the right answer!
(Theo also said so and I think he was absolutely correct)
Also could you please tell if there are parameters regarding the porosity of
Bonsai mixture? Has anybody conducted research or study on *porosity*. If
you pour water over gravel, the water will drain out in seconds. And if you
do the same on fine grit say with 1 to 2 mm sized particles, it will still
drain out quickly. Likewise it will pass out quickly through fine sand
(dust free) or may take a little longer. How porous the Bonsai potting mix
should be for different climatic conditions? If you have some information
please share.





************************************************** ******************************
++++Sponsored, in part, by Boon Manakitivipart++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++

Wow ... thanks for the science lesson Brent !

Mark Hill

-----Original Message-----
From: Internet Bonsai Club ] On Behalf Of
Brent Walston
Sent: Saturday, November 27, 2004 8:27 PM
To:
Subject: [IBC] Microelemnts

snip
A tall pot will retain LESS water than a low flat pot of the same volume
with the same soil.
/snip

Brent
EvergreenGardenworks.com


************************************************** ******************************
++++Sponsored, in part, by Boon Manakitivipart++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++

Brent;

It appears from your drainage logic that my cascade pots should contain soil
that is more able to retain water at higher elevations.
This logic also suggests that I shouldn't water my cascades as often, and
that dryness tests should be performed lower into the soil.
Hmmmmmm ..... now you've got me thinking .... maybe I should consider
changing the soil in my cascades this spring.

Mark Hill

************************************************** ******************************
++++Sponsored, in part, by Boon Manakitivipart++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++

HI Anil


Anil Kaushik wrote:

Brent

Thank you for the comprehensive reply. At last I got the right answer!
(Theo also said so and I think he was absolutely correct)
Also could you please tell if there are parameters regarding the porosity of
Bonsai mixture? Has anybody conducted research or study on *porosity*. If
you pour water over gravel, the water will drain out in seconds. And if you
do the same on fine grit say with 1 to 2 mm sized particles, it will still
drain out quickly. Likewise it will pass out quickly through fine sand
(dust free) or may take a little longer. How porous the Bonsai potting mix
should be for different climatic conditions? If you have some information
please share.
Someone few montha ago said something right
I do not remember his name
but this person was living in very hot and dry places and he said that
he could grow bonsai in totally different soils than the ones adviced
in northern countries , so soils has to be adapetd to the climate un
first with regard to teh kind of tree we are repotting

I proceed as follows to see the time of drying out

I take my hard material that is lava or pouzzolana of stone grit
washed from dusts and akadama well sifted
I select for my trees thata re genereally 70 cm 3 ft tall 3 to 5
mm diameter and must be really coarse this is why lava is ok
I add some home made soil that changes from plant to plant for
maples I add 25 % for pines 10 % mix well and also according to his
phase of growth and age ( but
so 10 to 20 % of home made compost and the rest in equal parts
akadama and lava or just lava ..
I can add sequoia bark cut in dices , is like a sponge.. and make
the quantitiy of one pound 500 grs put it in bonsai container
sink into water very well
and than put in the location as if it was a bonsai pot
and check everyday the umidity ..
this mix opften takes one week 8-9 days to dry well in may june sunny
weather in switzerland .. if it is windy takes less with a plant
inside takes a little less
so you can be almost be sure that that mix with a bonsai inside will
stay humid 6 days with no problem and 1 -2 more days without needing
watering if is a pine ( of course it also depends upon the pot size
if deep or flat if small or large ) for mame or shohim teh small
quantity of soil dries within hours no matter how damp might be

Tested that I change the components according my needs

thin sands retains water in the very beginning but dries out quickly
coarse sand makes the water flow away very quickly
peat if dries too much has a difficulty to get wet again and clogs
lava retains inside water and release t slowly almost like akadama
but does not disgregate
warms up quickly in the sun and roots grow well

I did that when left home for one week and I had no problema with my
trees




--
MSN messanger / or ICQ 25 666 169 4
Private Mail :
«»«»«» Just for today... don't worry .....be happy «»«»«»

HI Anil


Anil Kaushik wrote:

Brent

Thank you for the comprehensive reply. At last I got the right answer!
(Theo also said so and I think he was absolutely correct)
Also could you please tell if there are parameters regarding the porosity of
Bonsai mixture? Has anybody conducted research or study on *porosity*. If
you pour water over gravel, the water will drain out in seconds. And if you
do the same on fine grit say with 1 to 2 mm sized particles, it will still
drain out quickly. Likewise it will pass out quickly through fine sand
(dust free) or may take a little longer. How porous the Bonsai potting mix
should be for different climatic conditions? If you have some information
please share.
Someone few montha ago said something right
I do not remember his name
but this person was living in very hot and dry places and he said that
he could grow bonsai in totally different soils than the ones adviced
in northern countries , so soils has to be adapetd to the climate un
first with regard to teh kind of tree we are repotting

I proceed as follows to see the time of drying out

I take my hard material that is lava or pouzzolana of stone grit
washed from dusts and akadama well sifted
I select for my trees thata re genereally 70 cm 3 ft tall 3 to 5
mm diameter and must be really coarse this is why lava is ok
I add some home made soil that changes from plant to plant for
maples I add 25 % for pines 10 % mix well and also according to his
phase of growth and age ( but
so 10 to 20 % of home made compost and the rest in equal parts
akadama and lava or just lava ..
I can add sequoia bark cut in dices , is like a sponge.. and make
the quantitiy of one pound 500 grs put it in bonsai container
sink into water very well
and than put in the location as if it was a bonsai pot
and check everyday the umidity ..
this mix opften takes one week 8-9 days to dry well in may june sunny
weather in switzerland .. if it is windy takes less with a plant
inside takes a little less
so you can be almost be sure that that mix with a bonsai inside will
stay humid 6 days with no problem and 1 -2 more days without needing
watering if is a pine ( of course it also depends upon the pot size
if deep or flat if small or large ) for mame or shohim teh small
quantity of soil dries within hours no matter how damp might be

Tested that I change the components according my needs

thin sands retains water in the very beginning but dries out quickly
coarse sand makes the water flow away very quickly
peat if dries too much has a difficulty to get wet again and clogs
lava retains inside water and release t slowly almost like akadama
but does not disgregate
warms up quickly in the sun and roots grow well

I did that when left home for one week and I had no problema with my
trees




--
MSN messanger / or ICQ 25 666 169 4
Private Mail :
«»«»«» Just for today... don't worry .....be happy «»«»«»