perlite

[Jaz]

Need to wash the fine dust off perlite before use. Fine white dust size particles in the bag, and they'll harden like concrete in medium if not flushed with water.

I just flushed my coco peat, I hear you're supposed to do that till it runs clear to rid it from salt(s).

I put an amount in a washing tub and filtered it through an old tea towel.

I noticed in the bottom of the tub, if you swirl it like a gold panner, there is a fine grit which settles, like crushed concrete - which I tossed out.

j

 

[afghan bob]

Here ya go
Picture worth 1000 words
Or about 10 of mine

 

[Jaz]

Here ya go
Picture worth 1000 words
Or about 10 of mine

What are we looking at?

Are you saying you pulled out the bit you transplanted ages ago and the roots couldn't break through the perlite concrete dust that set?

j

 

[afghan bob]

Umm no, trying 2 show u what root ball looks like after scraping off perlite and sprinkling microbes over said root ball before placing in pre-prepared hole made from exact pot dimensions of plant ure transplanting
Sheesh... i thoughts pics said it all

 

[Jaz]

Sheesh... i thoughts pics said it all

lol, there was discussion of perlite dust setting like concrete, wondered how you got that hole so perfectly rounded and set like that.

j

 

[afghan bob]

When u building ure next size or final pot, just stick same size pot ure transplanting into final pot and add medium around it and when finished withdraw it 2 leave perfect hole

 

[itchybro]

if your putting stones or perlite or sand / anything at the bottom of pots for extra drainage
you might want to do some research into the "Perched Water Table" in pots to understand
how water will travel through a pot of soil of differing layers

"The layer of gravel creates an area for the water to drain through to escape. The creation of drainage
commonly involves a layer of gravel. , “Logical thinking 101.” , Yes ?

this isn’t logical thinking: it’s intuitive. It’s what we think is going to happen in the absence of any evidence.
And in this case, it’s wildly inaccurate.

The fact is, when water moving through a soil reaches a interface between different soil types, it stops moving.
Here’s a photo from a very old research paper on the topic:



A layer of silt loam sits above a layer of sand, and water from an Erlenmeyer flask drips in.
Intuition says that when the water reaches the sand, it will move more quickly through the
sand because the pore spaces are larger than those in the silt loam.
But intuition is wrong,
as this series of photographs clearly demonstrate. Water is finally forced into the sand layer
by gravitational pressure, only after saturation of the silt loam that can not hold anymore water

if the soil you use drains adequately there is no need to add drainage to the bottom of a pot
removing the stones at the bottom leaves more space for soil organic matter & organisms to
feed on & convert to plant nutrients
adding stones at the bottom of a pot the problem of over watering can become more of a possibility

 

[Aye Shroomer]

if your putting stones or perlite or sand / anything at the bottom of pots for extra drainage
you might want to do some research into the "Perched Water Table" in pots to understand
how water will travel through a pot of soil of differing layers

"The layer of gravel creates an area for the water to drain through to escape. The creation of drainage
commonly involves a layer of gravel. , “Logical thinking 101.” , Yes ?

this isn’t logical thinking: it’s intuitive. It’s what we think is going to happen in the absence of any evidence.
And in this case, it’s wildly inaccurate.

The fact is, when water moving through a soil reaches a interface between different soil types, it stops moving.
Here’s a photo from a very old research paper on the topic:



A layer of silt loam sits above a layer of sand, and water from an Erlenmeyer flask drips in.
Intuition says that when the water reaches the sand, it will move more quickly through the
sand because the pore spaces are larger than those in the silt loam.
But intuition is wrong,
as this series of photographs clearly demonstrate. Water is finally forced into the sand layer
by gravitational pressure, only after saturation of the silt loam that can not hold anymore water

if the soil you use drains adequately there is no need to add drainage to the bottom of a pot
removing the stones at the bottom leaves more space for soil organic matter & organisms to
feed on & convert to plant nutrients
adding stones at the bottom of a pot the problem of over watering can become more of a possibility

Man I love science. Wish I paid more attention in school though lol.

 

[Jaz]

The fact is, when water moving through a soil reaches a interface between different soil types, it stops moving.
Here’s a photo from a very old research paper on the topic:

I recall watching a gardening show many years back (could've been Burke or Cundall's show), where the host of the segment said to ditch placing stones or layer of newspaper at the bottom of pots. It doesn't make drainage better.

j

 

[afghan bob]

Still gonna do it

 

[Billygoat]

Geez that is interesting @itchybro, definitely not what I expected.

 

[afghan bob]

Yeah, i know u all about the facts Itchy, but in fabric pots and fully washed perlite, i've never had a problem with drainage or over-watering
I do bow down 2 your superior knowledge of science but

 

[Jaz]

Still gonna do it

Why not do both?

It's always good to experiment and see which gives better results.

j

 

[Pikey]

Still gonna do it

I didn't think your reason for doing it was for drainage anyway was it? Wasn't it to aid in transplant and the application of mycorrhizae to the roots? Do you let your pots free drain or does water sit in a saucer?

Yeah, i know u all about the facts Itchy, but in fabric pots and fully washed perlite, i've never had a problem with drainage or over-watering
I do bow down 2 your superior knowledge of science but

My thinking would be that the increased water mobility/fast capillary action of perlite (over sand) would encourage a greater wicking action and, therefore, draw more moisture from the soil? Combined with the increase in soil moisture evaporation that the fabric pots give you, I imagine it would result in a much different hydration pattern. Especially if it is only a relatively thin layer or perlite at the bottom of the pot.

That's what I think anyways, but I'm no expert

 

[Jaz]

I didn't think your reason for doing it was for drainage anyway was it? Wasn't it to aid in transplant and the application of mycorrhizae to the roots? Do you let your pots free drain or does water sit in a saucer?


My thinking would be that the increased water mobility/fast capillary action of perlite (over sand) would encourage a greater wicking action and, therefore, draw more moisture from the soil? Combined with the increase in soil moisture evaporation that the fabric pots give you, I imagine would it would result in a much different hydration pattern. Especially if it is only a relatively thin layer or perlite at the bottom of the pot.

That's what I think anyways, but I'm no expert

 

[afghan bob]

I didn't think your reason for doing it was for drainage anyway was it? Wasn't it to aid in transplant and the application of mycorrhizae to the roots? Do you let your pots free drain or does water sit in a saucer?


My thinking would be that the increased water mobility/fast capillary action of perlite (over sand) would encourage a greater wicking action and, therefore, draw more moisture from the soil? Combined with the increase in soil moisture evaporation that the fabric pots give you, I imagine would it would result in a much different hydration pattern. Especially if it is only a relatively thin layer or perlite at the bottom of the pot.

That's what I think anyways, but I'm no expert

Yep, only thin layer about 20 mil, so when roots grow in 2 perlite much easier 2 expose and treat with microbes
Perlite always comes off easy, no crusty layer probs cause give it a good rinse before using
Found the occasional plant that dries out super quick and have 2 use saucer but normally no saucers 4 bob

 

[Jaz]

My thinking would be that the increased water mobility/fast capillary action of perlite (over sand) would encourage a greater wicking action and therefore, draw more moisture from the soil?

My thinking is, the wicking action ceases when there's no soil underneath to wick to. Perlite absorbs the water where it will sit and will have to rely on air drying among all the little gaps, drying from the surface area of each perlite granule and eventually inward toward the centre.

When you first water you'll have quite a bit of water in that layer, then it'll be very dry quicker than usual, so the roots will either be saturated or dried out?

Depends how thick that perlite layer is, the granule size and how long the roots are in that layer before you transplant?

I guess the best way to find out is experiment with all things being equal bar the perlite layer at the bottom.

j

 

[afghan bob]

All good points but as long as u give it a good wash before and use fabric.....no worries
Only thing is occasional flush or good watering as u dont seem 2 get a lot of run off when feeding

 

[itchybro]

Still gonna do it

, perfect reply

Yeah, i know u all about the facts Itchy, but in fabric pots and fully washed perlite, i've never had a problem with drainage or over-watering
I do bow down 2 your superior knowledge of science but

don't bow down to anybody bob
do yo thing bro

That's what I think anyways, but I'm no expert

none of us are experts individually
but maybe us together could amount to something

 

[itchybro]

you can definitely put stones at the bottom of a pot
growing plants in containers is all about management
just need to understand the pros & cons as bob has done

bob has mentioned his pros , the cons are , a higher propensity to over water if you don't manage the pot well
the flow on over watering effect is , if a section of soil stays waterlogged it will go anaerobic , roots will not want
to move & grow into minimum or zero oxygen soil , this decreases your container size & there for plant size as well