Greensand carries minerals from the ocean to your garden.
Greensand is a collection of minerals from ocean sediments deposited long ago. The primary constituent is glauconite, which incorporates potassium, magnesium, iron and aluminum in its structure. If enough glauconite is present in the sediment, a greenish color occurs, which is why greensand is so named. Because greensand is rich in potassium and magnesium, it's been used as an organic fertilizer since the 1760s. Does this Spark an idea?
Source
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
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. In addition to glauconite, greensand can contain up to 30 other substances, including phosphorus, silicon, chromium, calcium, potash and lime. The additional materials aren't necessarily part of the glauconite complex, but tag-along substances that were incorporated into the soil alongside the glauconite.
Fertilizer
As a fertilizer, greensand provides slow-release potassium and magnesium for plants. Potassium deficiency turns leaves yellow and causes them to develop brown edges. Older leaves may cup downward, while 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. Once plants show signs that they're low in potassium or magnesium, greensand won't work fast enough to remedy the situation. In this case, it's best to add greensand to the soil in fall and allow it to provide long-term benefits.
Application
Many soils are already high in potassium, so 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 your garden soil. Mineral fertilizers such as greensand aren't highly soluble, so they release their nutrients slowly, taking several years before they deplete their reserves. 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.
Soil Conditioner
In addition to its use as an organic fertilizer, greensand is an excellent soil conditioner. It has the ability to absorb up to 10 times more water than generic sand, which allows it to bind sandy soils. Greensand also conditions clay soils by breaking up the sticky particles and facilitating drainage.
Tags: potassium magnesium, your garden, curl upward, fertilizer greensand, from ocean
