Wollastonite as a soil amendment?

budtoker221

Well-Known Member
Wollastonite (calcium silicate) as a soil amendment to boost resistance to PM
Has anyone ever used this amendment?
I know theres many common soil components that contain silica like sand and vermiculite but this seems a bit different. I’m thinking of adding this to a coco/perlite medium but I’m not sure if it would just wash a way or actually do anything.

 
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crimsonecho

Well-Known Member
it says it raises ph (as much as or even more so than lime) and decreases available mg, is that something you want?
 

budtoker221

Well-Known Member
Yeah good call im actually trying to get away from amendments as much as possible I was gonna switch from potassium silicate (protekt) to amending with this but maybe I’ll just use less protekt and not use any during late flower I’m just trying to use less products overall and I feel like the potassium silica affects the flavor a bit if it’s used in flower.
 

effexxess

Well-Known Member
Bugbee at Utah State University is using wollastonite in their greenhouse mix.

It's suppose to release Si throughout the grow cycle.

It does indeed pop pH by as much as a point. They recommend 1g/L Wollastonite, about a tablespoon per gallon i think,
which isn't much, so might not affect the soil pH overall.

Dr. Bugbee lectured that he believes silicon is key to trichome development!

Attached "Bioavailable silicon: release rate from additives & substrates" from USU.
 

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Mike Parent

Active Member
Bugbee at Utah State University is using wollastonite in their greenhouse mix.

It's suppose to release Si throughout the grow cycle.

It does indeed pop pH by as much as a point. They recommend 1g/L Wollastonite, about a tablespoon per gallon i think,
which isn't much, so might not affect the soil pH overall.

Dr. Bugbee lectured that he believes silicon is key to trichome development!

Attached "Bioavailable silicon: release rate from additives & substrates" from USU.
According to the link Wollastonite doesn’t raise the ph in peet out CoCo.
“- It is unknown why the pH of peat and coconut coir-based media with wollastonite did not increase over time.”
 

RCJR

Active Member
Bugbee at Utah State University is using wollastonite in their greenhouse mix.

It's suppose to release Si throughout the grow cycle.

It does indeed pop pH by as much as a point. They recommend 1g/L Wollastonite, about a tablespoon per gallon i think,
which isn't much, so might not affect the soil pH overall.

Dr. Bugbee lectured that he believes silicon is key to trichome development!

Attached "Bioavailable silicon: release rate from additives & substrates" from USU.
Is this supposed to be added to the soil 1 time or multiple times throughout the life cycle?
 

RCJR

Active Member
Sorry, didn't directly answer the question. Mixed in once when blending the soil. Good luck!

Saw some on eBay: Wollastonite-calcium Silicate -vansil W -20 __2 Lb

Maybe let us know how it goes, too?
Update, I mixed it in once with promix hp at the 1g per liter of media. Plants look great and I don't have proof but ive been fighting small amount of powdery mildew in flower for over a year (perpetual grow) . I haven't changed anything in my garden but the wollastonite and my powdery mildew is gone. Stalks are stiff enough to hold big buds without falling over like they always have. I added the wollastonite in my veg plants and top dressed my flowering plants at the time of my original reply. I just wonder if I'm flushing all the wollastonite out in my runoff and I should top dress in the beginning of flower since the wollastonite goes in the pot for a 2 month veg then flower.
 

hillbill

Well-Known Member
I use some Diatomaceous Earth in my mixes in powdered form and also use NAPA #8822 (expanded DE) Floor Dry much like I would Vermiculite
 

effexxess

Well-Known Member
Wow! Great feedback and results from your wollastonite grow :bigjoint:

Yes, the Silicon from the wollastonite is leaching from the growing medium so I would top dress at 2 months, and here's why I think that ...
Dissolution of Silicon from Soilless Substrates and Additives (Opens a PDF research paper by Dey, Boldt, and Bugbee in 2023.)

So each time you water, some silicone (Si) is weathered and erodes from the wollastonite pebbles. Here's a chart of that happening! Leaching fraction tells us how much water was added to 1L of growing medium; 60%=600ml, 30%=300ml, and 15=150ml.

I think you can top dress after 60 days.
1731373831978.png

This chart tells us at each day, how much more is being added to the total cumulative since the start?

I think this shows how the wollastonite pebbles have gotten depleted after a few months and there is no incremental addition of Si. And, from the looks of it, more water = more silicone and faster.
Ok to top dress after 60 days, I think.
1731374783773.png
 
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RCJR

Active Member
Wow! Great feedback and results from your wollastonite grow :bigjoint:

Yes, the Silicon from the wollastonite is leaching from the growing medium so I would top dress at 2 months, and here's why I think that ...
Dissolution of Silicon from Soilless Substrates and Additives
PDF research paper by Dey, Boldt, and Bugbee in 2023.

So each time you water, some silicone (Si) is weathered and erodes from the wollastonite pebbles. Here's a chart of that happening! Leaching fraction tells us how much water was added to 1L of growing medium; 60%=600ml, 30%=300ml, and 15=150ml.

I think you can top dress after 60 days.
View attachment 5439091

This chart tells us at each day, how much more is being added to the total cumulative since the start?

I think this shows how the wollastonite pebbles have gotten depleted after a few months and there is no incremental addition of Si. And, from the looks of it, more water = more silicone and faster.
Ok to top dress after 60 days, I think.
View attachment 5439095
Wow! Great feedback and results from your wollastonite grow :bigjoint:

Yes, the Silicon from the wollastonite is leaching from the growing medium so I would top dress at 2 months, and here's why I think that ...
Dissolution of Silicon from Soilless Substrates and Additives
PDF research paper by Dey, Boldt, and Bugbee in 2023.

So each time you water, some silicone (Si) is weathered and erodes from the wollastonite pebbles. Here's a chart of that happening! Leaching fraction tells us how much water was added to 1L of growing medium; 60%=600ml, 30%=300ml, and 15=150ml.

I think you can top dress after 60 days.
View attachment 5439091

This chart tells us at each day, how much more is being added to the total cumulative since the start?

I think this shows how the wollastonite pebbles have gotten depleted after a few months and there is no incremental addition of Si. And, from the looks of it, more water = more silicone and faster.
Ok to top dress after 60 days, I think.
View attachment 5439095
Top dress at the original 1 gram per liter of media?
 
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