Perlite v. Pumice

[Missi 983]

Coarse pumice or coarse perlite...which would be better in a potting mix for potted understory palms? Please also explain why. 

[Fusca 1,899]

I couldn't tell you which is better, but I'd tend to want to use pumice over perlite assuming that it behaves more like Turface MVP in a container.  Every time I use perlite it ends up working it's way to the top of the container.  I haven't looked for pumice lately (never used) but I've been happy using the Turface.  Nice to see you posting again Missi - glad you are still around!  

[Silas_Sancona 4,658]

43 minutes ago, Missi said:

Coarse pumice or coarse perlite...which would be better in a potting mix for potted understory palms? Please also explain why. 

Pumice.. period.. 

No matter how you water, Perlite is notorious for floating up out of potting mixes, which allows all the organics/ finer sand, etc in the mix to settle and compact thus greatly reducing any benefit it might provide in terms of making the mix lighter / more well draining / allowing air to penetrate into the mix..  Almost anything i have grown over the years that i either made the mistake of using perlite in.. or had it in the mix when purchased suffered adversely before i stopped using perlite and started using Pumice, Grow stones ( company is out of business, or restructuring atm.. ) and Turface MVP.  Can also use stuff like crushed / course Coral gravel ( or Aragonite ) for drainage, esp. for palms which like limestone. Big Box stores in FL. also sold a product called " Paver Base " that is crushed Limestone. Wish i had local access to.. /  brought more of the stuff with me. 

Another advantage of Pumice ..and the other suggestions, vs. Perlite, They can be recycled/ re-used..  When something conks out, or is repotted, i sift / wash through the remaining  soil, and store in milk jugs / buckets.. Have probably saved $$$ doing this vs. buying more material this past year.  Do this with " River Grit " i started collecting out of a wash last year also. Later, plan on using Coconut peat/ coir as my main organic component in soil mixes for stuff that needs it.





Cacti in the bucket were from a plant that rotted last summer ..because it was put into bad / heavily organic soil, and some perlite ( before it washed out of the mix ) at the nursery i'd bought it from.

Edited March 23 by Silas_Sancona
edit

[Missi 983]

1 hour ago, Fusca said:

I couldn't tell you which is better, but I'd tend to want to use pumice over perlite assuming that it behaves more like Turface MVP in a container.  Every time I use perlite it ends up working it's way to the top of the container.  I haven't looked for pumice lately (never used) but I've been happy using the Turface.  Nice to see you posting again Missi - glad you are still around!  

Hello and thank you!! I got a bit sidetracked with learning more about Aroids and terrarium plants over the past year and a half or so, but now I’m back to my true love: palms!  And I missed this place! 

I have quite a few potted palms that are going to need to be repotted in a month or so. I’m finding, with the plants failing to thrive that I’ve repotted over the last year, the clay bits sometimes seem too heavy for the roots, or make the soil part of the potting media puddle up into muddy bleh in certain areas and I’m worried the baked clay amendments might just be too heavy so I was on the look for lighter amendments that will help the roots “breathe”. I completely agree with you re: perlite always coming to the top regardless of how well it is mixed in with the soil. When I repotted some of my plants in a simple potting mix + extra perlite recipe, the bottom half is muck and the top half contains the perlite. Very frustrating! I have been using a 50/50 mix of Miracle Gro potting soil and amendments including: pine and fir bark fines, pumice, calcined clay, montmorillonite clay, black lava, and charcoal all ingredients in around 1/4” pieces. It’s mostly the Aroid roots that have issues getting through and around the clay bits. I have noticed the same thing with some of the palms I repotted last summer, though. I’m just terrified of smothering roots.

[Missi 983]

1 hour ago, Silas_Sancona said:

Pumice.. period.. 

No matter how you water, Perlite is notorious for floating up out of potting mixes, which allows all the organics/ finer sand, etc in the mix to settle and compact thus greatly reducing any benefit it might provide in terms of making the mix lighter / more well draining / allowing air to penetrate into the mix..  Almost anything i have grown over the years that i either made the mistake of using perlite in.. or had it in the mix when purchased suffered adversely before i stopped using perlite and started using Pumice, Grow stones ( company is out of business, or restructuring atm.. ) and Turface MVP.  Can also use stuff like crushed / course Coral gravel ( or Aragonite ) for drainage, esp. for palms which like limestone. Big Box stores in FL. also sold a product called " Paver Base " that is crushed Limestone. Wish i had local access to.. /  brought more of the stuff with me. 

Another advantage of Pumice ..and the other suggestions, vs. Perlite, They can be recycled/ re-used..  When something conks out, or is repotted, i sift / wash through the remaining  soil, and store in milk jugs / buckets.. Have probably saved $$$ doing this vs. buying more material this past year.  Do this with " River Grit " i started collecting out of a wash last year also. Later, plan on using Coconut peat/ coir as my main organic component in soil mixes for stuff that needs it.

Ok, thank you!! And genius idea to rinse and reuse the amendments! I have wasted so much not doing this! I just ordered a big bag of of coco coir to add to my potting media so I can start using less soil. I’m excited to see how much better my plants do in this new and improved mix! Thanks for the ideas!

[Silas_Sancona 4,658]

2 minutes ago, Missi said:

Ok, thank you!! And genius idea to rinse and reuse the amendments! I have wasted so much not doing this! I just ordered a big bag of of coco coir to add to my potting media so I can start using less soil. I’m excited to see how much better my plants do in this new and improved mix! Thanks for the ideas!

Trust me, lol.. without realizing it, wasted a lot of the Pumice / Turface / Growstone components in mixes when i'd dump out pots in the yard/ planter box out front. With some plants i'd bought that were in soil that looked chunky enough, i was shocked to see how much fine sand/ decayed muck ( and even thick pieces of Mulch ) rinsed out when washed/ sifted.. 

Coco coir ( less so for chunky sized stuff ) will break down a little over time,  but no where near as much / as quickly as peat does..  It also supposedly contains natural compounds that are supposed to discourage/ inhibit soil borne pathogens ( bacteria/ fungi that can cause things like root rot / damping off ).  As you probably know, GREAT addition to soil mixes for any Anthuriums / Orchids you may be growing in Baskets / Net Pots. Almost always retained just the right amount of moisture between soakings there in FL.

How's the rest of your yard coming along?

[Reyes Vargas 278]

Where would someone buy Turface MVP or Coarse pumice cheaply.  I want to make my own cacti potting mix and am currently using Perlite.

[PalmatierMeg 5,928]

I use perlite, coarse soil and coco coir in my latest potting mix. Most people in FL don't even know what pumice is - a light volcanic rock created in eruptions - much less sell it. It is also significantly heavier than perlite and adds a lot of weight to potted plants. I use pumice to pot my rare potted cacti and it cuts down on deaths from overwatering & high FL humidity. I get my pumice in 15lb boxes from General Pumice in CA. A box costs less than $30 including shipping. And I rinse and reuse it. I get 11 lb pkgs of compressed coco coir through Amazon and as I am a member of Amazon Prime I get free shipping. I monitor the site daily because sometimes they offer unannounced 1-day sales. I recently bought 3 blocks of coir for $12.99 each, delivered at a savings of $3.01 per block. Each block makes 18 gal. of uncompressed coir.
 

[PalmatierMeg 5,928]

13 minutes ago, Reyes Vargas said:

Where would someone buy Turface MVP or Coarse pumice cheaply.  I want to make my own cacti potting mix and am currently using Perlite.

I don't know about TX but pumice in reasonable amounts is unavailable in FL. I get my pumice from General Pumice in CA for under $30 for a 15lb box, delivered. "Cheap" and "pumice" aren't generally found linked.

https://www.generalpumice.com/

I've read a lot of conflicting info about turface and decided to pass on it.

[Silas_Sancona 4,658]

9 minutes ago, Reyes Vargas said:

Where would someone buy Turface MVP or Coarse pumice cheaply.  I want to make my own cacti potting mix and am currently using Perlite.

If you can't find it in any local Hydroponic/ Garden supply places there ( know it isn't as accessible in other parts of the country as it is here in the west ) you may have to purchase Pumice online ( see it offered on E-bay ..can't remember bag / LB sizes sold )  Turface MVP you should be able to find at any good Lawn and Irrigation Supply store.. Not sure if the company has sales locations there but Ewing Irrigation is where i have bought it here / in other areas.

Would think you should have access to river grit ( Assume it would be more limestone based than what i collect here which is derived of Granite, in most areas ) Regardless, fantastic for Cacti, esp. stuff that needs a soil mix high in Calcium/Limestone..

With Cacti like Trichocereus/ Echinopsis, you can include more Coco peat in the mix ( they, and other Cacti from S. America tend to tolerate more organics than many of the native cacti here/ there in TX/ Mexico )

[Fusca 1,899]

23 minutes ago, Reyes Vargas said:

Where would someone buy Turface MVP or Coarse pumice cheaply.  I want to make my own cacti potting mix and am currently using Perlite.

Reyes,

Check out Ewing Irrigation 1312 E Upas Ave McAllen, TX 956-661-9530  They sell the Turface MVP in 50 lb bags for less than $15 (at least around SA).

 

[Reyes Vargas 278]

Thank you @PalmatierMeg @Silas_Sancona @Fusca I appreciate all that information.

[Darold Petty 2,638]

Pumice only,  perlite is bad stuff, floats up and then develops a nasty, dirty look.    

[Missi 983]

16 hours ago, PalmatierMeg said:

I don't know about TX but pumice in reasonable amounts is unavailable in FL. I get my pumice from General Pumice in CA for under $30 for a 15lb box, delivered. "Cheap" and "pumice" aren't generally found linked.

https://www.generalpumice.com/

I've read a lot of conflicting info about turface and decided to pass on it.

Can you please share what conflicting information you have read about it? I'm finding, when using baked clay pieces mixed with peat based soil, it just seems too heavy and the soil builds up on top and under where the clay bits settle in the pot and it gets all muddy. Also, where the clay bits collect, the roots have a hard time getting through.

[Missi 983]

I am definitely experiencing the floating issues with the normal, small-sized perlite, but am wondering if larger, more coarse perlite would stay-put better. Anyone have experience with that? If I was to get coarse perlite, I'd be getting the product below. Y'all think that'd still float? I'm nervous now that Meg mentioned pumice is heavy.

[Darold Petty 2,638]

The material, perlite, is the same density, so yes the larger chunks will float also.  

Pumice may be more expensive and difficult to obtain east of the Rockies, but it is a clearly superior product for the application of increased porosity and water retention. 

[Silas_Sancona 4,658]

47 minutes ago, Darold Petty said:

The material, perlite, is the same density, so yes the larger chunks will float also.  

Pumice may be more expensive and difficult to obtain east of the Rockies, but it is a clearly superior product for the application of increased porosity and water retention. 

Float away / Blow away ( here, lol.. )

2 hours ago, Missi said:

I am definitely experiencing the floating issues with the normal, small-sized perlite, but am wondering if larger, more coarse perlite would stay-put better. Anyone have experience with that? If I was to get coarse perlite, I'd be getting the product below. Y'all think that'd still float? I'm nervous now that Meg mentioned pumice is heavy.

Regarding weight, true.. mixes containing Pumice might be slightly heavier, depending on the ratio of pumice used compared to the other components in the overall mix ..but really isn't " heavy " unless constantly soaked ( which isn't good for anything, regardless of how much Pumice is in the soil mix )  Even plants where Pumice makes up 85% of the soil mix aren't much of a hassle to move around when needed.

On the other hand, the River/Wash grit i also use can be quite heavy where it makes up most of the %' age in a few things.. Those are more experiments rather than something i aim to utilize more.  Regardless, The one thing i like about heavier soil mixes. they don't blow over as easily.

With Turface.. Mixing it with Peat.. say 50/50, or 30% Turface / 70% Peat isn't a great idea.. Both retain quite a bit of moisture between soakings, esp. in the cooler months, and the Peat may break down faster, especially there in FL.  Made a similar mistake here ( ..and mixing Truface w/ sand, w/out anything else chunkier/ to " open up " the mix.. ) and it stayed wayy too wet for too long.   Coco peat/ Coir may act differently, but still wouldn't mix it and just  Turface..

Have a pair of Frankincense ( Boswellia sacra ) that are in 85-90% Turface.. No issues with finer roots moving through it. Bird- deposited Mex. Fan Palms ( =  ), and seedlings of some of my Rain Lilies also pop up in the same pots, with ease..

[OC2Texaspalmlvr 670]

Turface is a great product and I use it with just about everything from germinating seeds to 15gal pots. The ratio is key for sure tho. I have found with seedlings over 50% turface in your mix it can really become compacted. Which in turn holds more water and some roots struggle to navigate thru. 

T J 

[Missi 983]

20 hours ago, Silas_Sancona said:

Float away / Blow away ( here, lol.. )

Regarding weight, true.. mixes containing Pumice might be slightly heavier, depending on the ratio of pumice used compared to the other components in the overall mix ..but really isn't " heavy " unless constantly soaked ( which isn't good for anything, regardless of how much Pumice is in the soil mix )  Even plants where Pumice makes up 85% of the soil mix aren't much of a hassle to move around when needed.

On the other hand, the River/Wash grit i also use can be quite heavy where it makes up most of the %' age in a few things.. Those are more experiments rather than something i aim to utilize more.  Regardless, The one thing i like about heavier soil mixes. they don't blow over as easily.

With Turface.. Mixing it with Peat.. say 50/50, or 30% Turface / 70% Peat isn't a great idea.. Both retain quite a bit of moisture between soakings, esp. in the cooler months, and the Peat may break down faster, especially there in FL.  Made a similar mistake here ( ..and mixing Truface w/ sand, w/out anything else chunkier/ to " open up " the mix.. ) and it stayed wayy too wet for too long.   Coco peat/ Coir may act differently, but still wouldn't mix it and just  Turface..

Have a pair of Frankincense ( Boswellia sacra ) that are in 85-90% Turface.. No issues with finer roots moving through it. Bird- deposited Mex. Fan Palms ( =  ), and seedlings of some of my Rain Lilies also pop up in the same pots, with ease..

Thanks so much for the input!  I have a 3 gallon bag of coarse pumice on the way I'm super excited to start using this in my potting mix because I am imagining much happier roots!

[Missi 983]

Just got my 3 gallon bag of pumice from General Pumice Products Saturday. That's what you call FAST shipping!! Can't wait to start using it!

[Laaz 1,294]

Turface MVP hands down out performs both. NEVER use "potting mix". Use garden soil mix 50/50 with turface, you wont be sorry.

[Missi 983]

On 4/5/2021 at 2:38 PM, Laaz said:

Turface MVP hands down out performs both. NEVER use "potting mix". Use garden soil mix 50/50 with turface, you wont be sorry.

YIKES! Can you please share why you recommend garden soil over potting mix "soil"?

[Laaz 1,294]

Garden soil is chunks of bark & drains well. Potting soil is like powder & turns to sludge very quickly.

[Missi 983]

20 hours ago, Laaz said:

Garden soil is chunks of bark & drains well. Potting soil is like powder & turns to sludge very quickly.

Why don't potting soil companies up their game? Like, which plants like smothered roots? I don't get it. I'm starting to use coco coir instead of soil in my potting mixes. That'll work, right?

[Silas_Sancona 4,658]

14 minutes ago, Missi said:

Why don't potting soil companies up their game? Like, which plants like smothered roots? I don't get it. I'm starting to use coco coir instead of soil in my potting mixes. That'll work, right?

Like many things related to plants, horticulture, etc.. since many consumers don't take the time to do their homework, inc. researching soil -to much, if any degree- Let alone placing all their faith in using the cheapest option(s) available.  Many manufacturers take full advantage of that lack of knowledge, and sling the cheapest garbage possible.. Jungle Grow was a decent product, but apparently not enough people saw the value in spending a few extra $ for it, compared to say Miracle Gro -anything-. 

[Missi 983]

UGH! RIP Jungle Grow! Even Walmart carried it!! I miss it. 

[Silas_Sancona 4,658]

18 minutes ago, Missi said:

UGH! RIP Jungle Grow! Even Walmart carried it!! I miss it. 

Was a great foundation to work from when adjusting soil mixes at home.

[Merlyn 1,277]

My mix was generic Lowe's topsoil, with 30% perlite and 30% coarse sand.  The sand really weighed it down, and compacted into slurry.  So I replaced the sand with Sakrete Paver Base, which in FL is crushed limestone.  My theory was that the limestone would (somewhat) neutralize the tendency of soil in pots to go acidic, and keep the pH at least in the reasonable range.  This made a dramatic improvement in growth on my nursery area.  I'm not sure if it was due to the larger pieces of limestone (similar to small river grit) being better than sand, or due to the lime counteracting the acidic soil.  The lime may actually be a horrible idea for most palms except Cuban Copernicias.    Last fall I switched to 30% generic topsoil, 30% perlite, and 30% Turface MVP.  For agave and cacti I just increase the inorganics, depending on the species.

I tried pumice for a while, but perlite is $8.50 per cubic foot...and pumice is $72.50 per cubic foot.  Nope.  I haven't had issues with perlite floating up out of a mix, except immediately after potting it.  Maybe since my "topsoil" is mostly ground up bark chunks, it doesn't "float up" in the mix?  When I've planted palms and cycads out of pots I haven't found a striated mix, where there's perlite towards the top and organics compacted out in the bottom.  I don't know why.

One issue that's kept me from using coco coir bricks is the negative reviews on Amazon.  I can get 5kg blocks for $14 to $30 or so, but there's always reviews saying things like, "I expanded this with 10 gallons of water and read 700ppm salts."  Do you just buy stuff from General Hydroponics or Mother Earth, and wash it out really well before using it?  For example, @Missi the General Hydroponics CocoTek 5kg is $14.09 right this minute...

I also considered using some of my cypress mulch as a lightening mix in the pots.  Cypress is slow to break down, and is supposedly antimicrobial/antibacterial.  Since I get 10 cubic yards delivered for $250, that's only $0.92 per cubic foot.  I've not read of people using it in potting mixes, so maybe there's a good reason...

[Missi 983]

2 hours ago, Merlyn said:

My mix was generic Lowe's topsoil, with 30% perlite and 30% coarse sand.  The sand really weighed it down, and compacted into slurry.  So I replaced the sand with Sakrete Paver Base, which in FL is crushed limestone.  My theory was that the limestone would (somewhat) neutralize the tendency of soil in pots to go acidic, and keep the pH at least in the reasonable range.  This made a dramatic improvement in growth on my nursery area.  I'm not sure if it was due to the larger pieces of limestone (similar to small river grit) being better than sand, or due to the lime counteracting the acidic soil.  The lime may actually be a horrible idea for most palms except Cuban Copernicias.    Last fall I switched to 30% generic topsoil, 30% perlite, and 30% Turface MVP.  For agave and cacti I just increase the inorganics, depending on the species.

I tried pumice for a while, but perlite is $8.50 per cubic foot...and pumice is $72.50 per cubic foot.  Nope.  I haven't had issues with perlite floating up out of a mix, except immediately after potting it.  Maybe since my "topsoil" is mostly ground up bark chunks, it doesn't "float up" in the mix?  When I've planted palms and cycads out of pots I haven't found a striated mix, where there's perlite towards the top and organics compacted out in the bottom.  I don't know why.

One issue that's kept me from using coco coir bricks is the negative reviews on Amazon.  I can get 5kg blocks for $14 to $30 or so, but there's always reviews saying things like, "I expanded this with 10 gallons of water and read 700ppm salts."  Do you just buy stuff from General Hydroponics or Mother Earth, and wash it out really well before using it?  For example, @Missi the General Hydroponics CocoTek 5kg is $14.09 right this minute...

I also considered using some of my cypress mulch as a lightening mix in the pots.  Cypress is slow to break down, and is supposedly antimicrobial/antibacterial.  Since I get 10 cubic yards delivered for $250, that's only $0.92 per cubic foot.  I've not read of people using it in potting mixes, so maybe there's a good reason...

I am using Mother Earth coco coir and they say it is pre-rinsed and buffered. People are saying it has 0 ppm. That’s why I chose that product rather than the generic compressed blocks. What are your thoughts?

[Merlyn 1,277]

11 hours ago, Missi said:

I am using Mother Earth coco coir and they say it is pre-rinsed and buffered. People are saying it has 0 ppm. That’s why I chose that product rather than the generic compressed blocks. What are your thoughts?

If you check the Mother Earth reviews and click on the button that filters by "salt content," there are only 4 of them out of ~700.  One says they measured 600ppm, the second says 700ppm.  I found similar comments on other brands too, so it seems that pre-washing any of the coco coir blocks is probably a good idea.  Of course, you have to take Amazon reviews with...er...a grain of salt.