rock dust?

[lovelightpower]

i've bought myself a 20kg bag of "rock dust";
powdered volcanic rock.

this can be used for feeding plants (well bacteria, fungi and worms which in turn feed the plants), and i believe it can also be used instead of lime.

has anyone else heard of this stuff.

 

[rckymtnthuglife]

I know glacial rock dust contains alot of trace elements that are very slow to release. Wouldn't be worth using unless you reuse your soil.
As far as using it instead of lime...I don't believe it contains enough Mg or Ca, nor does it buffer your soil against pH swings like lime would.JMHO.
Peace
Rocky

 

[lovelightpower]

cool man, i'm just quoting what it said on the bag,
i think i will ring them see what really gwan!

 

[MHHSP]

"rock dust" provides around...

Available Phosphoric Acid (P205) 0.003%
Soluble Potash (K20) 0.007%
Calcium (Ca) 4.0%
Magnesium (Mg) 1.5%
Iron (Fe) 6.0%

Looks like a good source of Ca, Mg, and Fe.
Probably an ok substitute for lime.
However that alone wouldn't be sufficient for feeding the plants.

 

[medical_shed]

I use rockdust from the organic catalogue (v. cheap delivery), it's not a feed though just a soil amendment. You'll notice a difference especially if used with Rootgrow. It's great never having to mess about with epsom salts etc.

 

[lovelightpower]

i am experimenting now with worm castings, beneficial bacteria/fungi and rock dust in my mix for potting cuttings. so far they look really good, in fact better than others not potted in this mix.
it would be nice not having to worry about whether or not to add cal mag to my water.
a nice organic substitute.
i also have a lot of trouble finding dolomite lime round these parts

 

[jaykush]

what kind of rock dust, theres tons of them out there. best use would be grinded into a powder and then mixed into the soil. depending on what type of rock dust it is, it should contain minerals, some nutrients in unavailable form and trace elements.

i use azomite for my rock dust.

 

[medical_shed]

It's a brand name in the UK Jaykush http://www.seercentre.org.uk/ Comes from a hill in Scotland. I think it may be basalt, not sure.

 

[jaykush]

cool cool, soil minerals are always the least though about when mixing soil. imo it has a major impact on overall health, yield and potency. n-p-k only gets you so far, the minerals and trace elements fill in those tiny gaps in the soil chain for the best finished product.

almost all of the mixes i see on here could benefit from rock dusts.

 

[mexilandrace]

i am experimenting now with worm castings, beneficial bacteria/fungi and rock dust in my mix for potting cuttings. so far they look really good, in fact better than others not potted in this mix.
it would be nice not having to worry about whether or not to add cal mag to my water.
a nice organic substitute.
i also have a lot of trouble finding dolomite lime round these parts

I can't find dolomite lime either, I just use hydrated lime at about 2/3 the dosage as I would regular lime. Everyone here acts like it is totally different and will rot your hands off, its over blown.

I also use rock dust, green sand, and any other cool organic stuff I see in the store when I make it into town.

 

[MHHSP]

and what's the deal with places not having dolomite lime?? You would think garden/hydro shops would stock the right shit...I always see the hydrated form which is much more fast acting then dolomitic lime.

 

[mexilandrace]

and what's the deal with places not having dolomite lime?? You would think garden/hydro shops would stock the right shit...I always see the hydrated form which is much more fast acting then dolomitic lime.

It may be more fast acting, but it pretty much acts the same once it is in the soil. If you dissolve it in water then use that water on your plants, I have found it pretty comparable to if I had mixed dolomite lime in with my soil mix. You use less hydrated lime by volume for the same about of dirt.

I guess if you have a really off PH then maybe it wouldn't work, but I have never had a problem.

 

[Mr Celsius]

I bought a lifetime (essentially 50kg) of glacial rock dust... I don't have the bag on me, but it has 8 micros and I think a macro or two in there. I add a tbs on top of the 2 tbs of dolomite. Reuse of soil also helps with it.

 

[quadracer]

rock dust is great. It is hard to burn your plants with it, and greatly improves the CEC of soil.

My fruits trees love it. I'll add some to my beds in the fall and in the spring.

I'll mix it into my indoor soil before a grow, then some after when everything is complete.

I'll also throw some in the compost pile.

I have Azomite and some Glacial Rock Dust, and they are almost the same product.

 

[lovelightpower]

and what's the deal with places not having dolomite lime?? You would think garden/hydro shops would stock the right shit...I always see the hydrated form which is much more fast acting then dolomitic lime.

yeah, what is the deal with that??? i've been badgering my grow shop to get some for ages, they even tried and couldn't get any.
all i could get was garden lime (screened limestone), bah!
my experimenting with rock dust is going great, in my mix and top dressing i have had wonderful results with my vegative plants.

 

[MHHSP]

hmmm I may be wrong but pretty sure "garden lime" is considered dolomitic in most cases. I guess one way to check would be to look at the Mg content if listed. Dolomitic lime consists of 35% to 46% magnesium carbonate.

 

[lovelightpower]

i thought limestone was different to dolomite?

 

[bakelite]

i thought limestone was different to dolomite?

Hydrated lime contains only Calcium (Calcium Hydroxide) while Dolomite contains Mg and Ca (Calcium Magnesium carbonate). Hydrated lime is stronger.

 

[CT Guy]

rock dust is a great fungal food in teas...just fyi

 

[lovelightpower]

thanks for the info guys!