What Does Greensand Do for Soil Fertility?
Greensand is one of the most highly recommended soil additives for its ability to draw in and retain moisture while also adding slow-releasing nutrients. It has been used as a natural mineral fertilizer for centuries, but has seen a particular resurgence in popularity as more commercial farms strive for coveted organic certifications and home growers have shied away from harmful artificial chemicals. Greensand will counteract drying effects in any area and with any soil type, but delivers especially dramatic improvement in desert and clay environments. It will also deliver vital nutrients. This combination dramatically increases the fertility and sustainability of your soil.
What Greensand Is
Greensand is a sandstone rock that slightly resembles glass while also being chalky to the touch. It is abundant in Europe and North America around the coasts. Its color and texture are due to the mineral glauconite, an iron potassium silicate with low weathering resistance. Unlike unstable nitrogen fertilizers, greensand is non-corrosive and non-toxic, so will not harm your skin or surrounding animal life (including mischievous pets). Because of this, it will also not kill the important microorganisms and worms that you worked so hard raising in your compost and mulch.
Why You Need Greensand
The primary cause of soil infertility is a loss of moisture. Moisture is important not only because your plants need water, but for the long-term sustainability of the soil. Often times allowing your soil to dry up causes irreparable damage. Excessively dry soil becomes substantially altered in its porosity. Soil then becomes like clay and like a compressed sponge, suddenly unable to retain new moisture. Water leeching into the water table is not immediately evident and will have already seriously eroded precious root-level soil before you will have the chance to correct or even notice the problem.
Greensand prevents these effects by promoting soil moisture in two ways. Firstly, the greensand's potassium makeup attracts water, drawing moisture from the evaporation prone surface toward the roots. Secondly, this attracting property holds moisture in place until used by plants or replaced by new saturation. When aplied in the proper amounts, greensand will add nutrients and retain moisture to your soil, increasing plant vitality and longterm soil sustainability.
Greensand not only improves your soil's moisture retention but also provides vital, water soluble nutrients. Greensand primarily delivers soluble potash (potassium that dissolves in water), stable nitrogen and calcium while also containing variable levels of up to 30 other plant-usable minerals.
Apply at 16 lbs. per 1000 sq. feet for lawns, 30 lbs. for flower and vegetable gardens, two ounces (1/3 cup) per bush for roses and two tablespoons per gallon of potting mix. If you are dealing with a particularly dry climate or clay soil, increase these amounts by up to 10 percent. Greensand should be mixed into soil, compost or mulch when possible. However, its low weathering resistance means that if you missed this opportunity, it works well to sprinkle generous amounts around the base of plants. The greensand will then break down and recede down to root level. There is no wait time before the areas become safe for skin contact as with artificial fertilizers.