Wicked Organics · Fertilizer Guide
Green Sand
NPK 0-0-3OrganicOMRI Listed
Greensand is one of the few certified organic sources of potassium — the third essential macronutrient that plants need for water regulation, disease resistance, winter hardiness, and overall vigor. Mined from ancient ocean floor deposits, greensand is composed primarily of the iron-rich mineral glauconite, which releases potassium and...
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Nutrient Breakdown
N · Nitrogen
0%
N/A — Greensand contains no nitrogen.
P · Phosphorus
0%
N/A — Greensand contains no phosphorus.
K · Potassium
3%
Provides 3% slow-release potassium from the mineral glauconite, along with iron, magnesium, silica, and over 30 trace minerals.
Derived from: Naturally occurring marine sedimentary deposits of the mineral glauconite
Overview
What It Is
Greensand (glauconite) is a naturally occurring mineral formed millions of years ago on ancient ocean floors. Over geological time, layers of marine sediment rich in iron, potassium, and silicates compacted into a soft, crumbly rock that gets its distinctive green color from its iron-potassium silicate composition.
As a fertilizer, greensand has an NPK of 0-0-3, making it a slow-release potassium source. However, it also contains iron, magnesium, silica, and over 30 trace minerals in naturally chelated forms that plants can use efficiently. The minerals release gradually as soil chemistry and microbial activity break down the glauconite particles.
Greensand’s physical properties are equally valuable: its ability to absorb moisture and improve soil structure makes it a permanent soil improvement. Unlike compost or organic matter that decomposes over time, greensand’s mineral structure persists in soil indefinitely.
As a fertilizer, greensand has an NPK of 0-0-3, making it a slow-release potassium source. However, it also contains iron, magnesium, silica, and over 30 trace minerals in naturally chelated forms that plants can use efficiently. The minerals release gradually as soil chemistry and microbial activity break down the glauconite particles.
Greensand’s physical properties are equally valuable: its ability to absorb moisture and improve soil structure makes it a permanent soil improvement. Unlike compost or organic matter that decomposes over time, greensand’s mineral structure persists in soil indefinitely.
Crop Fit
Best For
Greensand benefits virtually all plants through its potassium, trace minerals, and soil conditioning properties. Tomatoes and peppers use potassium for fruit quality and disease resistance. Fruit trees and berries benefit from improved winter hardiness. Roses produce stronger stems and more vibrant color. Lawns become more drought-tolerant. Any soil — sandy or clay — improves with greensand.
Application Rates
How Much to Use
| Garden & beds | 5-10 lbs per 100 sq ft |
|---|---|
| Lawn | 44-50 lbs per 1,000 sq ft |
| Trees & shrubs | 1-2 lbs per inch of trunk diameter |
| Containers | 1-2 tbsp per gallon of soil |
| Frequency | Annually or every 1-2 years based on soil test |
Step by Step
How to Apply
1
Soil Test
Test soil to determine potassium and trace mineral needs. Greensand is a slow-release potassium and mineral source.
2
Application Rate
Calculate rate — 5–10 lbs per 100 sq ft for gardens. Sandy soils benefit from higher rates.
3
Broadcast
Broadcast evenly over the garden bed for uniform mineral distribution.
4
Incorporate
Work into the top 3–6 inches of soil to maximize contact with the root zone.
5
Water In
Water thoroughly after application to begin slow mineral release.
6
Reapply
Reapply annually or every 2 years based on soil tests. Greensand releases nutrients very slowly.
For garden beds, broadcast 5-10 lbs per 100 sq ft and work into the top 3-6 inches of soil. For containers, add 1-2 tablespoons per gallon of soil. For trees, spread 1-2 lbs per inch of trunk diameter around the base to the drip line. For lawns, apply 44-50 lbs per 1,000 sq ft. Greensand is completely non-toxic and will not burn plants even if over-applied — though following soil test recommendations ensures efficient use.
Handling & Timing
Safety & Season
Safety & Storage
Greensand is completely safe to handle — no gloves, mask, or protective equipment needed. It is non-toxic to children, pets, and wildlife. Store in a dry location to prevent clumping. Bags are heavy — plan accordingly for transport.
Seasonal Notes
Apply greensand in early spring as part of bed preparation or in fall before winter. Its slow-release nature means timing is less critical than with soluble fertilizers. For clay soils, fall application allows freeze-thaw cycles to help work greensand into the soil structure over winter.
In Context
How It Compares
Greensand vs. Sul-Po-Mag: Sul-Po-Mag (0-0-22) provides much more concentrated potassium for quick corrections, along with magnesium and sulfur. Greensand (0-0-3) releases potassium slowly and provides superior soil conditioning. Use Sul-Po-Mag for immediate potassium needs; greensand for long-term soil building. Greensand vs. Kelp Meal: Both provide potassium and trace minerals, but kelp meal also contains growth hormones and amino acids. Greensand provides better physical soil conditioning.
Answers
Frequently Asked Questions
What is greensand?
Greensand is a natural mineral soil amendment mined from ancient ocean floor deposits rich in the mineral glauconite. It contains approximately 3–5% potassium along with iron, silica, magnesium, and over 30 trace minerals. Greensand is valued as a slow-release potassium source, soil conditioner, and mineral supplement that improves soil structure, water-holding capacity, and nutrient availability over time. It is OMRI-Listed for organic production and has been used by farmers and gardeners for centuries. Old Cobblers Farm™ Wicked Organics Greensand is a premium-grade organic mineral amendment for building healthier, more productive soil.
What is greensand used for in the garden?
Greensand serves multiple roles in the garden. As a potassium source, it slowly releases K₂O for plant uptake over months to years. As a soil conditioner, it loosens heavy clay soils and improves water retention in sandy soils. As a mineral supplement, it provides iron, silica, magnesium, and dozens of trace elements that support plant health. It is especially popular in organic gardens for long-term soil building, and it is safe to use at any time without risk of burn. Old Cobblers Farm™ Wicked Organics Greensand provides multi-function soil improvement from a single natural mineral source.
How do I apply greensand to my garden?
Apply greensand by broadcasting 5–10 pounds per 100 square feet and incorporating into the top 4–6 inches of soil. For individual planting holes, add 1–2 tablespoons. For established beds, top-dress with 2–5 pounds per 100 square feet and water in. Greensand can be applied at any time of year and cannot burn plants even at heavy rates. For long-term soil building, apply annually and the benefits compound over time as minerals become increasingly available. Old Cobblers Farm™ Wicked Organics Greensand is easy to spread and safe at any application rate.
Does greensand provide potassium?
Yes, greensand contains approximately 3–5% potassium (K₂O), which releases very slowly as the glauconite mineral weathers and breaks down in soil. This slow release means greensand is not a quick-fix potassium source — it is best viewed as a long-term soil builder that gradually improves potassium availability over months to years. For immediate potassium needs, use muriate of potash (0-0-60) or sulfate of potash. Greensand excels as a sustained mineral supplement that builds potassium reserves. Old Cobblers Farm™ Wicked Organics Greensand provides gentle, long-lasting potassium along with dozens of trace minerals.
Is greensand good for clay soil?
Yes, greensand is excellent for improving clay soil. The angular mineral particles help break up compacted clay, improving drainage, aeration, and root penetration. Over time, regular greensand applications create a more crumbly, workable soil structure. The mineral content also enhances nutrient availability in clay soils, which often lock up nutrients in forms plants cannot access. Apply 10–15 pounds per 100 square feet and incorporate deeply for maximum soil-loosening benefit. Old Cobblers Farm™ Wicked Organics Greensand is one of the best natural amendments for transforming heavy clay into productive garden soil.
What trace minerals does greensand contain?
Greensand contains over 30 trace minerals including iron, silica, magnesium, calcium, phosphorus, manganese, cobalt, boron, zinc, copper, and molybdenum. These micronutrients play essential roles in plant enzyme function, chlorophyll production, disease resistance, and nutrient uptake efficiency. Many garden soils become depleted of trace minerals over years of cropping, leading to subtle deficiencies that reduce plant health and yield. Regular greensand application replenishes this broad mineral spectrum naturally. Old Cobblers Farm™ Wicked Organics Greensand is one of the most mineral-diverse soil amendments available for organic gardens.
Can I use too much greensand?
Greensand is one of the safest soil amendments available — it cannot burn plants and there is no practical upper limit on application rates for garden use. Even heavy applications will not cause nutrient toxicity because the minerals release so slowly. Typical rates of 5–15 pounds per 100 square feet are effective for most garden applications. Higher rates simply accelerate the long-term soil-building effect. The only consideration is cost-effectiveness, as very heavy rates provide diminishing returns per pound. Old Cobblers Farm™ Wicked Organics Greensand is forgiving and safe for gardeners of all experience levels.
