Wicked Organics Organic Organic OMRI Listed

Bone Char

NPK 0-16-0

Bone char is a unique soil amendment that combines the phosphorus and calcium benefits of traditional bone meal with the carbon-rich, microporous structure of biochar. Created by heating animal bones at high temperatures in the absence of oxygen (pyrolysis), bone char delivers slow-release phosphorus and calcium while simultaneously improving soil structure, water retention, and microbial habitat.

With an approximate NPK of 0-16-0, bone char is a concentrated phosphorus source that releases nutrients gradually over multiple growing seasons. Its carbon framework acts like a sponge in the soil — holding moisture, trapping nutrients that would otherwise leach away, and providing surface area for beneficial soil microorganisms to colonize.

Old Cobblers Farm™ Wicked Organics Bone Char is ideal for gardeners who want the dual benefits of phosphorus fertilization and long-term soil building. Apply it at planting time or mix into garden beds to create a lasting reservoir of phosphorus and calcium that feeds your plants season after season.

Application Rates FAQs
Nutrient Profile
WO-BONE-CHAR
0–16–0
Bone Char
Derived From
  • Animal bones charred at high temperatures (pyrolyzed bone material)
0-16-0
NPK Ratio
Organic
Formula Type
Once every 3-5 years
Feeding Frequency
—
Compatible Plants
What It Is

Understanding 0-16-0

Bone char is produced by heating animal bones to temperatures between 400-500°C in a low-oxygen environment. This pyrolysis process burns off organic matter and nitrogen while concentrating phosphorus and calcium into a highly porous carbon matrix. The result is a lightweight, dark granular material that functions as both a fertilizer and a soil conditioner.

Unlike raw bone meal, bone char's nutrients are released extremely slowly — over years rather than months. The porous structure of bone char also gives it exceptional cation exchange capacity, meaning it can hold and slowly release other nutrients applied alongside it. This makes it particularly valuable in sandy soils that struggle with nutrient retention.

Bone char has a long agricultural history, particularly in tropical farming systems where it has been used to build lasting soil fertility similar to the famous Amazonian terra preta (dark earth) soils.

N
Nitrogen — 0%

N/A — Bone char contains negligible nitrogen due to the high-temperature charring process that volatilizes nitrogen compounds.

P
Phosphorus — 16%

Provides 16% slow-release phosphorus along with approximately 30% calcium. The charred structure creates micropores that improve nutrient retention in soil.

K
Potassium — 0%

N/A — Bone char contains no significant potassium.

Recommended Plants

Best For

Fruit Trees
Perennial Berries
Root Vegetables
Tomatoes
Peppers
Asparagus
Roses
Garlic

Growing Detail

Bone char is ideal for long-lived perennial plantings like fruit trees, berry bushes, and asparagus beds where its multi-year phosphorus release matches the plant's lifespan. Root vegetables benefit from both the phosphorus and improved soil structure. Tomatoes and peppers use the calcium to prevent blossom end rot while the phosphorus supports fruit production.
Dosing Guide

Application Rates

Garden Beds
3-5 lbs per 100 sq ft
Container / Pot
1-2 tbsp per gallon of soil
Water Mix
N/A — Bone char is not water-soluble
Lawn
N/A — use bone meal or rock phosphate for lawn phosphorus needs
Trees
2-5 lbs mixed into backfill soil per tree
Per Acre
500-1,000 lbs per acre
Frequency
Every 2-4 weeks

How to Apply

Seasonal Notes

Apply bone char in spring when preparing beds or at any time when planting trees and perennials. Fall application before planting garlic or cover crops works well. Since bone char is extremely stable, timing is less critical than with faster-release amendments.
How It Compares

Side by Side

Bone char vs. Bone Meal: Bone meal (3-15-0) releases phosphorus over 1-4 months and includes nitrogen. Bone char (0-16-0) releases phosphorus over years and also improves soil structure like biochar. Bone char vs. Biochar: Standard biochar provides carbon and soil structure but minimal nutrients. Bone char provides both carbon structure and concentrated phosphorus/calcium.

Safety & Storage

Bone char is non-toxic and safe to handle. Wear a dust mask when applying to avoid inhaling fine particles. Store in a cool, dry location in a sealed container. Unlike raw bone meal, bone char has minimal odor and is less likely to attract animals.

Got Questions?

Frequently Asked

  • Bone char is a natural phosphorus and calcium fertilizer made by heating animal bones at high temperatures in a low-oxygen environment. This charring process creates a highly porous, carbon-rich material with approximately 16% phosphorus (P₂O₅) and 20–30% calcium. Unlike raw bone meal, bone char is more stable, less likely to attract animals, and releases phosphorus more gradually. It also provides a biochar-like soil conditioning effect that improves soil structure and microbial habitat. Old Cobblers Farm™ Wicked Organics Bone Char is a premium organic phosphorus source for gardens, farms, and landscapes.
  • Bone char and bone meal both come from animal bones but are processed differently. Bone meal is ground raw or steamed bones with higher phosphorus (around 12–15%) and some nitrogen (2–4%). Bone char is bones heated through pyrolysis at high temperatures, producing a carbon-rich material with similar phosphorus levels but added soil-conditioning benefits. Bone char is more stable in soil, breaks down more gradually, attracts fewer digging animals, and improves soil porosity like biochar. Old Cobblers Farm™ offers both Wicked Organics Bone Char and Bone Meal so growers can choose the phosphorus source that best fits their needs.
  • Apply bone char by broadcasting 2–5 pounds per 100 square feet and incorporating into the top 4–6 inches of soil before planting. For individual transplants, mix 1–2 tablespoons into each planting hole. For trees and shrubs, apply ½–1 cup around the base and work into the soil. Because phosphorus does not move readily through soil, incorporating bone char into the root zone is important for maximum effectiveness. Water thoroughly after application. Old Cobblers Farm™ Wicked Organics Bone Char provides slow-release phosphorus and calcium in an easy-to-apply granular form.
  • Bone char benefits any plant that needs phosphorus for root development, flowering, or fruiting. It is especially effective for bulbs, flowering annuals and perennials, roses, fruit trees, root vegetables, tomatoes, and transplants that need rapid root establishment. The calcium content also benefits plants prone to calcium-related disorders like blossom end rot in tomatoes and bitter pit in apples. Old Cobblers Farm™ Wicked Organics Bone Char is a versatile organic phosphorus amendment for flower gardens, vegetable plots, orchards, and landscape plantings.
  • Bone char is significantly less attractive to digging animals than raw bone meal. The high-temperature pyrolysis process removes most of the fats, proteins, and odors that attract raccoons, skunks, dogs, and other animals to bone meal applications. While no organic amendment is completely animal-proof, bone char is a much better choice for gardens where animal digging is a concern — particularly when fertilizing bulb plantings, which are already vulnerable to animal disturbance. Old Cobblers Farm™ Wicked Organics Bone Char provides the phosphorus benefits of bone products with minimal animal attraction.
  • Bone char and biochar are related but different products. Both are produced through pyrolysis (high-temperature heating in low oxygen), but biochar is made from wood or plant material and primarily serves as a soil conditioner with little direct nutrient value. Bone char is made from animal bones and provides significant phosphorus (16%) and calcium (20–30%) along with soil-conditioning properties. Think of bone char as a nutrient-rich biochar — it improves soil structure while also feeding plants. Old Cobblers Farm™ offers both Wicked Organics Bone Char (for phosphorus + soil conditioning) and Bio Char (for pure soil conditioning).
  • Bone char typically provides approximately 16% phosphorus (P₂O₅) along with 20–30% calcium. This phosphorus concentration is comparable to bone meal and significantly higher than rock phosphate (12%). One pound of bone char applied to 50 square feet delivers meaningful phosphorus supplementation for most garden crops. The phosphorus releases gradually as soil microbes and mild soil acids break down the charred bone material, providing sustained availability over weeks to months. Old Cobblers Farm™ Wicked Organics Bone Char is a concentrated, long-lasting organic phosphorus source.

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