What's new

GREENSAND : What the heck is it? (fyi)

I.M. Boggled

Certified Bloomin' Idiot
"Greensand is a sand or sediment that consists largely of dark greenish grains of glauconite, usually mixed with clay or sand.

Their are three main places that mine Glauconite (greensand) in the United States, they are New Jersey, Texas and Arkansas.

It is a natural mineral that opens up tight soil and binds the loose soils.

Greensand is mainly potash and a hydrated silicate of iron.

It releases it's nutriential benefits through a exchange action in the soil to be taken up by the plants.

The mineral has been used for decades which contains a huge amount of Potassium and other trace minerals(as many as 30).

The Jersey greensand contains 20% iron oxide and 7% Potassium(Potash).

The ancient sea deposit is a slow release of Potash and the other essential minerals.

Since the 1700s greensand has been used as a fertilizer and soil conditioner that loosens clay soils and also increases the water holding capability of the sand and clay, when added to any soil will increase water holding properties.

Texas greensand also known as glittergreen holds pretty much same properties as New Jersey greensand.
Potassium and iron soil supplement recommended for a mulch, conditioning additive or top dressing. It slow releases nutrients, loosens soils and holds water.

In Arkansas greensand is found in Nacatoch and Ozan formations, which extend from the Arkansas-Oklahoma border to Arkadelphia.(?)
Here the glauconite is in a sandy marl that can be 2-10 feet thick and be as pure as 50%.
Marl is defined as
"A crumbly combination of limestone and clay that may be added to deficient soils."
Arkansas Geological Commission

Greensand is non-soluble in water but will not burn plants.

Safe to handle and is odorless...

Now if anybody would care to describe how they have used greensand succesfully before, or maybe organic soil mixes/ recipes that incorporate greensand, this would be a good place to post ones thoughts.
I have never used greensand before and would be interested in hearing the pros and cons (noticeable benefits?) on the subject of Greensand in organic style potting soil mixes.

IMB :)
Last edited:


Well-known member
Chat Moderator
oh yes, the magic of greensand.....greensand is kind of like nature's equivalent of those water-absorbing polymer crystals which absorb many times their weight in water and then slowly release it as the medium dries out....only whereas synthetic polymers might absorb 100 times their weight in water, greensand only absorbs around 5 to 10 times its weight, so it isn't as effective as the synthetics.....

greensand is also useful for its ability to very slowly release potassium (K).....this is beneficial because all too often these rapid release synthetic fertilizers release all their K at once and create nutrient burning and/or lockout.....so it is a good way to have some backup potassium to last all throughout flowering.....greensand also has a tiny bit of Phosphorous for flowering.....

i think some common fertilizer recipies combine blood meal with bone meal and greensand, giving a complete N-P-K regimen that is all organix.....something like 2 parts blood meal to 3 parts bone meal to 5 parts greensand.....add some gypsum and crushed limestone and you have an organic "cal-mag" product that supplies important minor nutrients to your blood/bone/greensand mixture and you are good to go......

Personally, i would use greensand for its water-retaining qualities and as a supplemental source of potassium and phosphorous- not as the primary source of these nutrients.....this is because it takes awhile for greensand to break down and you want to make sure you have some faster acting K for when your plants really need it with a quickness.....so using something like liquid kelp extract for fast K would be appropriate.....but if you have multiple sources of the major nutrients you ensure both short-release and long-release actions and this is ideal for the organic gardener....

greensand is good as a mulch, too.......some people use the ashes of wood as a substitute for greensand when it is not available but i have never really tried it.....

next lesson we will be learning about ZEOLITE......will be informative....-gp out


Active member
Using Texas greensand today. Same exact description nine years later. Using it in an organic soil.mix for flowering plants. I cant wait to find out how it does. Though it was expensive..... $30 for 40 lbs.


Active member
Oh yeah, I'm using two pounds in about 4 or 5 cubic feet of soil. anyone know if that sounds like a good ratio? I had to divide the directions for outdoor soil recommendation.


I used it at 1 1/2 cups per 120 gallons of soil mix ( 5'x6', 6 inches tilled). 50 lb bag from Peaceful Valley (#F1120) went on 37 plants. So, a little over a lb per plant.

Also added to the mix was:

1 1/2 cups Bat Guano (PV# F029)

1 cup each of:

Seabird Guano (F1939)
Alfalfa Meal (F035)
Kelp Meal (F1455)
GaiaGreenRock (F045)

1/2 cup each of:
Azomite (F040)
Humate (F535)
KMag (F2360)
Fishbone Meal (F312)
Crabshell Meal (F1962)
Fishmeal (F1055)
RockPhosphate (F2101)
Oystershell lime (F1850)

Also Sup'R green (F444) and EWC (F902) at 5 lbs per plant,
Last edited:


ICMag Donor
@ Cappy:

figure the max ratio would be 50# per 1000 sq ft

Basic till depth is 6.7in. or .56 ft

1000 sq ft x 0.56 ft = 560 cu ft

560 cu ft x 6.43 gal per cu ft = 3600.8 gallons

50 lbs x 453.59g = 22,679.5 grams

22,679.5g / 3600.8 gallons = 6.3 grams per gallon


40.5 grams per cu ft


Bio-availability of greensand is very low. It can take 4-6 months before ever seeing a nutritional benefit from it, making it best when used in soil you intend to recycle and reuse. However, it is still a great addition for soil tilth.



ICMag Donor
That project is on the back burner, so to speak...for now.Thanks for asking.



I have used green sand for years, great stuff. If you want it faster available to plants then add it to what you feed earthworms, if you are raising them. Then their worm castings are extra high in P and lots more soluble. Composting it helps also.

Latest posts

Latest posts