Perlite vs. Vermiculite

[swayland]

I am sure this question has come up in the past. I've started mixing my own potting soil and am utilizing equal parts peat, fine pine bark, sand and perlite. I have read that vermiculite can hold to much water and is not good for use in a potted palm mix. Is there any truth to this?

[PalmatierMeg]

I hate vermiculite - turns to sludge when wet. Perlite doesn't break down. Wear a mask when you mix it because of dust. Some people recommend sand but we have too much of it in Fl, it's heavy and packs when wet. For my prized succulents I use pumice but that costs $27 for 15 lbs from CA, which makes it totally impractical for palm growers who aren't independently wealthy. Same for the much ballyhooed lava rock. Most people in FL have no clue what pumice is. Geez, ditch the Kardashians and watch the Science Channel.

[swayland]

Thanks Meg. I'll stick with the perlite. I did buy of bag of the Mighty-Lite lava rock and used it in a couple of pots (one of which contained a Joey that I managed to kill), and it seems to work well. But I agree that if you have more than a couple of potted palms it's not economically sensible. 

[Silas_Sancona]

Completely agree with Meg.. forget Vermiculite, lost too many things when i used it due to it's water holding capacity ( CA= winter+ cold +wet ( FL = Summer Hot +wet, potentially too wet and cold during a wet winter)  Sand can work in certain instances ( as a top dressing around the root crowns of temperamental Cacti/Succulents) but sand which is only course grained, not the sugar fine stuff. Back in San Jose, it was often referred to as Horticultural sand.  Adding more than say 5% In a soil mix, made it too heavy.

As far as Pumice, like Meg had mentioned, i never understood why no one.. or pretty much no one, in Florida carried the stuff. If i needed it for a soil mix, i usually had to drive up to North Tampa to a Hydroponics store to get it and small bags( all they carried) weren't cheap. That was also the only place i found Gro Stones.. which i have referenced in other soil- related threads here. While a little pricey, this product filled the space reserved for large amounts of pumice. Looks and feels exactly like it and provides the same benefit. Have only used Perlite in a pinch since that stuff has a tendency to float up and out of a given soil mix.

Also highly recommend Turface ..Aka Calcined Clay. Just don't use too much since while it is great for retaining moisture, it can dry out quickly if it makes most of your soil mix.

Here in Arizona, i recently stumbled upon bags of Decomposed Granite which i am trialing in some soil mix batches for seeds and some Plumeria cuttings. Also researching sources for Zeolite.

While just personal observations, i have had very few problems with any of my plants using very open and peat-free soil mixes. They seemed to do much better since there was /is plenty of space for air to circulate through the root zone. Also encourages good micro growth. Regardless, As with anything, individual results may vary.

Here are a couple pictures of the components which make up 40-75% of my soil mixes, depending on the needs of the plants and availability of each ingredient.

#1 Left to right: L: Grow stones (top) Pumice (Bottom). Cntr: Turface (Calcined Clay Top) Decomp. Granite (Bottom/ trial). R: Lava rock ..Smallest grade, when i can find it (Top)


 

[Darold Petty]

Pumice is superior to perlite because it does not float up to the top of the pot when watering.  Perlite will form a rude, dirty crust on the top of the potting medium.

  Here in northern California the price for pumice is approximately $8.00 for a 0.75 cubic foot bag.  I add 1 part pumice to 4 parts commercial potting soil for my potted palms.

[PalmatierMeg]

If I could find pumice locally...... Grow Stones were too big to pot my succulents. Decomposed granite is as unknown as pumice. Lava rock is sometimes sold in prissy little bags for bonsai growers. About the only palms I'd consider for lava rock are my 5 Cham tuercks. Also, I've read that some lava rock (red, about all I've seen) contains excessive iron that could damage palms. I checked out Turface and read a litany of horror stories online, so I backed off from that. Which leaves perlite, which a local nursery sells in 4 cu ft paper bags. I can live with the floating bits.

[Phoenikakias]

Couldn't agree more with all above information! I wanted however to add that I was having recently a very positive experience with the use of zeolite in the size of coarse sand. It can substitute the sand while it is not that heavy and does not pack when wet like sand. In a miraculous way, it dries up quite fast (so that it does not pack) but retains also internally some water.

[Hammer]

Pumice is the way to go for all the reason mentioned.   Also add that perlite has a reputation for being a nasty hazard to our lungs.  I would avoid it if possible.

[Phoenikakias]

  On 4/15/2016 at 3:51 AM, Hammer said:

Pumice is the way to go for all the reason mentioned.   Also add that perlite has a reputation for being a nasty hazard to our lungs.  I would avoid it if possible.

Expand  

Is perlite harmful only during preparation of soil mix or also afterwards?

[Hamal]

I believe once perlite is wet, it is no longer dangerous. The perlite that I have here only develops dust when I pour it out of the bag. Now I only use it for germinating seeds, but when I still used it for my substrate, all was good once it was in the bucket and in contact with the other, especially organic components of the substrate.

BTW, if you do not have access to pumice (like me), you can also use lava rock or crushed burned clay instead. Their characteristics are very similar to pumice.

[Hammer]

  On 4/15/2016 at 8:28 AM, Phoenikakias said:

Is perlite harmful only during preparation of soil mix or also afterwards?

Expand  

I think Hamal's comment below is pretty accurate.  The perlite dust is bad news.  Just to be on the safe side, I never use the stuff. 

[PalmatierMeg]

If I could find enough pumice at a reasonable price, I would buy it. And the pumice I've received is not exactly dust-free. This time of year nothing in FL is dust-free. I have boxes of masks and use them freely. I've never seen zeolite available either.

[Neil C]

If you are having trouble locating zeolite it is often sold as either a fat absorber in the bbq section or as kitty litter. I guess just make sure not to buy the scented type.

Regards Neil

[foxtail]

  On 4/15/2016 at 10:12 PM, PalmatierMeg said:

If I could find enough pumice at a reasonable price, I would buy it. And the pumice I've received is not exactly dust-free. This time of year nothing in FL is dust-free. I have boxes of masks and use them freely. I've never seen zeolite available either.

Expand  

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=291031374532&_sacat=0

[jreich85]

  On 4/14/2016 at 6:12 PM, PalmatierMeg said:

I hate vermiculite - turns to sludge when wet. Perlite doesn't break down. Wear a mask when you mix it because of dust. Some people recommend sand but we have too much of it in Fl, it's heavy and packs when wet. For my prized succulents I use pumice but that costs $27 for 15 lbs from CA, which makes it totally impractical for palm growers who aren't independently wealthy. Same for the much ballyhooed lava rock. Most people in FL have no clue what pumice is. Geez, ditch the Kardashians and watch the Science Channel.

Expand  

I couldn't agree more! All of the "good ingredients" here in FL are pricey and only come in small packages. I'm still trying to work the perfect potting mediums out of mixes including perlite and builders sand myself.

[PalmatierMeg]

Zeolite sounds downright scary. It cleans up radiation a la Chernobyl, detoxes the body, treats cancer as well as keeps cats sanitary.

[Tom in Tucson]

I know that conditions are a whole lot different back east, but here in the southwest I've had good luck mixing readily available soil mixes. Try mixing something like Kellogg PALM, CACTUS, AND CITRUS mix with a good quality coir such as Cocogro bagged coir. The Kellogg mix uses pumice instead of the dangerous and inferior performing perlite. If you can't find a mix with pumice, you can substitute something like Growstone (which is basically synthetic pumice). It's even available with a blend of coir. For my climate a 75%/25% mix - coir/Kellogg works great.

 

Good luck with your mix!

 Tom Birt - Casas Adobes, AZ

Hi 80°, Lo 50°

[Phoenikakias]

  On 4/16/2016 at 11:22 PM, PalmatierMeg said:

Zeolite sounds downright scary. It cleans up radiation a la Chernobyl, detoxes the body, treats cancer as well as keeps cats sanitary.

Expand  

It may be needed for the sanitization of the Pacific Ocean, if human race decides finally to make earth again hospitable, instead of migrating to other planets.

[Phoenikakias]

  On 4/18/2016 at 1:29 AM, Tom in Tucson said:

I know that conditions are a whole lot different back east, but here in the southwest I've had good luck mixing readily available soil mixes. Try mixing something like Kellogg PALM, CACTUS, AND CITRUS mix with a good quality coir such as Cocogro bagged coir. The Kellogg mix uses pumice instead of the dangerous and inferior performing perlite. If you can't find a mix with pumice, you can substitute something like Growstone (which is basically synthetic pumice). It's even available with a blend of coir. For my climate a 75%/25% mix - coir/Kellogg works great.

 

Good luck with your mix!

 Tom Birt - Casas Adobes, AZ

Hi 80°, Lo 50°

Expand  

In a peculiar coincidence this ready- for - use soil mix contains all ingredients I also use to prepare my home made soil mix. I replace only coarse sand with finer zeolite, because we coarse sand from river beds is very rare to non existent in my region.