LESS PERLITE = BETTER?

[mad librettist]

not like it would with peat...

now you are getting how relative it all is.


when you say "perlite is porous", I think, "not like DE/charcoal/pozzolana/Turface/Attapulgite/fuller's earth/scoria/pumice!"

one is really porous in a way that makes a difference. Perlite is just barely better than gravel to me.


man, get thee to carquest, get a bag of part #8822, screen out the fines with bug screen, and root some cuttings in it. Pretty soon you will be talking shit about perlite.


for the question of media drainage characteristics, check out the dude I told you about in your rep. he is not an organic grower so i disagree with him on everything, but the dude knows media like no one else, and he grows insane plants in insane containers. I look at his pics and think "how did you get THAT to grow in THAT?!?". A big part of it is that his mix holds no perched water.

 

[cjk]

cool ... i'll check it out

 

[mad librettist]

happy searching, nice conversing with you.

I forgot to add - if you replace perlite with granite grit, which is not porous, you don't interfere with capillary action.

 

[schwagg]

. actually, the perlite makes my plants so root bound, i can't reuse my media!! LOL!

shit i'd be using all them old roots in my recycle.

 

[cjk]

shit i'd be using all them old roots in my recycle.

lol i do i was just being a dick...

 

[VerdantGreen]

hmm, cant say im buying this 'pudding' analogy either. soil / peat is made up of varying sized particles and 'crumbs' of smaller particles stuck together. surely the addition of perlite which is irregular sized chunks, will help keep these further apart, increasing aeration and drainage, and reduce the cumulative compaction effects of watering??

any links that will explain this further??? just trying to understand...

VG

 

[Yes4Prop215]

real glad i just visited this thread because it reminded me that i paid for 4 bags of chunky perlite today at the hydro shop....and totally forgot about it left it at the counter.....purple kush + shopping is not a good mix!

 

[mad librettist]

hmm, cant say im buying this 'pudding' analogy either. soil / peat is made up of varying sized particles and 'crumbs' of smaller particles stuck together. surely the addition of perlite which is irregular sized chunks, will help keep these further apart, increasing aeration and drainage, and reduce the cumulative compaction effects of watering??

any links that will explain this further??? just trying to understand...

VG

http://forums2.gardenweb.com/forums/load/contain/msg0316064615891.html?134

It seems like such a logical assumption that adding large particles to a mix would result in "average drainage" that is a compromise between the properties of the small particles in a mix and the large ones.

But the link above set me straight - this is not how it works in the real world. In the real world, the drainage characteristics of a medium are determined by the particles that are a majority of the mix.

So if your mix is 70% peat, compost, and topsoil (small particles), and 30% perlite (large particles), the drainage characteristics will be identical to the same mix without 30% perlite.

The container with the perlite will still dry faster and will still work better than the version without perlite. It's just not because you have altered drainage characteristics.

 

[VerdantGreen]

thanks mad, good link well explained - i still think there are some large generalizations made in there about the properties of 'soil' - but it has also changed my views somewhat.

one of the advantages of perlite is that it is an easily available and consistent amendment. things like composted pine bark fines are not so consistent and harder to get hold of. also, to a supplier, they may not think that the fact some other non-pine bark is in the pile matters - whearas to the grower it can be the difference between success and failure. spurr ran into this problem last time he posted a grow and had to abandon it in the end.

that said, its probably time to have a search in the UK to see if i can get hold of some fines - last time i looked a year or so ago they were impossible to source

VG

 

[mad librettist]

I'm not sure spurr's experience and mine looking for FUCKING PINE BARK FINES is a great recommendation for that method.

I'm almost sure it's better to minimize "drainage amendments", and maximize the amount and diversity of relatively new roots in my containers. White clover is not like having a dwarf tree in the pot. It's perennial, sure, but given appropriate media and space it does not get rootbound AFAIK. A perennial tree will develop thick old roots that can't absorb anything, even with the best airpot.

If i am just careful and i establish the living mulch well, I can use even more compost, even more topsoil. I can have what is technically the worst potting soil ever, in terms of the drainage and aeration characteristics of the medium itself.

 

[TACOE]

Madlib, your posts on this thread are epic. Lots of concepts for me to research when I get to some Internet.*

Quick dumb questions regarding your posts a page back
"Cp mix". What's that?
And something I have not been able to clarify: what is the difference between long and short fiber peat? *I usually use the finest processed stuff I can (pro gro). No sticks or pieces of woody looking stuff. Then I also have the cheaper stuff I use in my veggie gardens (ht tourbe de spaigne(sp)). Lots of chunks and woody looking stuff and lighter color. I have thought of that as "long fiber" (I have realized my understanding to be wrong)

 

[mad librettist]

long fibered sphagnum looks kind of like dreadlocks. it's cut from live plants. It's nice for lining a pot when you don't want seepage for aesthetic reasons.

CP mix is carnivorous plant mix. Traditionally 50/50 peat/perlite or peat/sand. During the growing season it's kept in a dish of distilled water at all times. The plant supplies oxygen and nutrients to the roots by absorbing them through the leaves, since the rhizosphere is anoxic. The roots are ropy, and their sole functions are anchorage and water supply.

 

[whatsupdoc]

So, to summarize:
Perlite creates an environment conducive to good root development.
Percentage is subjective, anywhere from 20 to 100%
Perlite does not hold water, so don't use it for said purpose.
We all want to grow good weed.

Did I get it right?

 

[TACOE]

So, to summarize:
Perlite creates an environment conducive to good root development.
Percentage is subjective, anywhere from 20 to 100%
Perlite does not hold water, so don't use it for said purpose.
We all want to grow good weed.

Did I get it right?

I don't think you did

Thanks ML. That clears that up. Can't say I've ever noticed long fiber for sale. Also haven't been searching

Is that what ppl sometimes use in hanging wire baskets?

 

[cjk]

So, to summarize:
1. Perlite can create an environment conducive to good root development.
2. Percentage is subjective, anywhere from 20 to 100%
3. Perlite does not hold water, so don't use it for said purpose.
4. We all want to grow good weed.

Did I get it right?

1. yes
2. percentage is subjective upon how often you can water and tend to the plants. the more peat %, the less often you will have to water if all other things are held constant. 100% perlite could be used but this would be hydroponics with a drip of flood method to keep up.
3. yes and no. perlite can hold water and/or air but should only be used for the latter as aerating is what it does best. moisture retention should be reserved for vermiculite, using less perlite, or introducing another medium such as compost, etc.
4. with healthy bright white root systems exposed to plenty of oxygen

 

[whatsupdoc]

Thanks cjk! I appreciate taking time to teach. Years of lurking, yet still learning!

 

[habeeb]

anyone got spurrs link on air porosity info?

also, doesn't it count that perlite allows a container to dry faster, thus more air into the root system faster?

also why if people are saying you need more then 50% of the media to make an effect, why add any perlite of it at all? why does mandala mike say to add 10%, if it doesn't matter unless its above 50% ?

 

[guineapig]

I thought it was a comment on how perlite and vermiculite are not the best for the environment....they are also hard to work with and you should wear a mask while doing so.....

A good alternative would be Zeolites....I wrote an article about zeolites awhile back....

kind regards from guineapig

 

[mad librettist]

anyone got spurrs link on air porosity info?

also, doesn't it count that perlite allows a container to dry faster, thus more air into the root system faster?

also why if people are saying you need more then 50% of the media to make an effect, why add any perlite of it at all? why does mandala mike say to add 10%, if it doesn't matter unless its above 50% ?

I think it counts! I've stated above that perlite does exclude some water. Less water = faster drying.

 

[ijim]

From what I understand is rocks and solids trap and hold oxygen and moisture as the moisture hydrates and is replaced by oxygen. Without solids like rock, sand or perlite the soil when it dries will shrink more and compact. I never remove rocks from my holes. And when I harvest I pull the rootballs up so I can reuse the same hole next year without dealing with the stubble. I always find fine hairy roots hugging the rocks and solids. Been digging them holes for 40 years the larger the hole with solids added the larger the rootball and yield. A cover crop such as clover catches non rain moisture such as dew and wicks it into the soil. Moves oxygen into the soil and the root system help keep the soil aerated. Without solids or a cover crop the top of the hole will muddy and dry with a solid skim on top that will shed water. Just my observation as a farmer.