Greensand also called glauconite is a mineral based organic fertilizer.

What is Greensand?

• Greensand is a mineral based organic fertilizer. Greensand is an organic fertilizer that contains the deposits of minerals.
• Greensand is also called “glauconite”.
• Greensand has a bluish-green color.
• The NPK ratio for greensand is approximately 0-0-3.
• It is a good organic source of potash which is important for overall plant health and disease resistance.
• It can also be applied at a rate of 50 to 100 pounds per 1000 square feet to improve clay soils.
• Greensand is also a useful component of container garden soils and seed starting mixes.
• Greensand is a collection of minerals from ocean sediments deposited long ago.
• The primary constituent is glauconite, which incorporates potassium, magnesium, iron, lime and aluminum in its structure.
• Greensand is rich in potassium and magnesium and hence it’s been used as an organic fertilizer since the 1760s.

Source of Greensand

• The only U.S. location with a greensand mining operation still in production is New Jersey.
• This state features 325,000 acres of greensand-bearing soil in a 100-mile strip of land.
• These concentrations of greensand exist along the coastal plain.

Formation and Composition of Greensand

• When greensand deposits are mined, the glauconite exists as pellets with a diameter of 0.5 to 4 mm.
• Some glauconite is also found in a form resembling mica flakes.
• Greensand contains up to 30 other substances, including:
- glauconite
- phosphorus
- silicon
- chromium
- calcium
- potash
- lime

Greensand as Fertilizer

• As a fertilizer, greensand provides slow-release potassium and magnesium for plants.
• Potassium deficiency turns leaves yellow.
• This causes them to develop brown edges.
• Older leaves may cup downward.
• New leaves curl upward.
• Stems grow hard, and fruit yields decrease.
• Magnesium deficiencies cause similar effects in leaves, although the veins remain green and the leaves curl upward.
• It’s best to add greensand to the soil in fall and allow it to provide long-term benefits.

Application of Greensand

• Perform a soil test before adding greensand to your garden.
• If a test shows a need for potassium, add 4 pounds of greensand per 100 square feet to garden soil.
• Greensand releases minerals over a period of 5 to 7 years.
• You can apply greensand to your garden before planting in spring, or at the end of the growing season in fall.

Greensand as Soil Conditioner

• Greensand is an excellent soil conditioner.
• It has the ability to absorb up to 10 times more water than generic sand.
• This allows it to bind sandy soils.
• Greensand also conditions clay soils by breaking up the sticky particles and facilitating drainage.