Types of organic fertilizers is a broad task, as many varieties are available, each with its own benefits. Below is a more extensive list, including some of the most commonly used organic fertilizers:

Animal-Based Fertilizers

1. Cow, Horse, and Sheep Manure: Rich in nutrients; best when well-composted to improve soil texture and nutrient content.
2. Poultry Manure: Higher in nitrogen than other manures; should be composted to avoid burning plants.
3. Bat Guano: A fast-acting, high-nitrogen fertilizer; also available in phosphorus-rich formulations.
4. Fish Emulsion: A liquid fertilizer high in nitrogen; good for leafy plants and rapid growth.
5. Fish Meal: A slower-release option than fish emulsion, providing nitrogen, phosphorus, and potassium.
6. Blood Meal: High in nitrogen; promotes leafy growth and effectively repels some pests.
7. Bone Meal: Phosphorus-rich; great for root and flower development.
8. Crab Meal: Good for calcium and phosphorus; also contains chitin, which boosts plant immunity.
9. Feather Meal: Another high-nitrogen option, slow-releasing and effective over the growing season.
10. Worm Castings: Excellent for providing a range of nutrients and improving soil structure.

Plant-Based Fertilizers

1. Compost: A balanced, slow-releasing source of nutrients; improves soil health and structure.
2. Cottonseed Meal: Acidic, making it suitable for plants that thrive in lower pH.
3. Alfalfa Meal: Provides nitrogen, along with trace minerals; also acts as a soil conditioner.
4. Soybean Meal: A balanced source of nitrogen and potassium.
5. Seaweed/Kelp Fertilizer: Rich in trace minerals and a natural growth stimulant.
6. Green Manure: Plants are grown and then tilled into the soil to add organic matter and nutrients.
7. Molasses: Used to feed beneficial microbes in the soil.
8. Peat Moss: A soil amendment that helps retain moisture and lower pH.
9. Cocoa Shell Mulch: Provides nitrogen, phosphorus, and potassium; also acts as a decorative mulch.

Mineral-Based Fertilizers

1. Rock Phosphate: A source of phosphorus and trace minerals.
2. Green Sand: Contains potassium and other trace minerals; also improves soil moisture retention.
3. Gypsum: Adds calcium and sulfur without altering soil pH.
4. Dolomite Lime: Provides calcium and magnesium and neutralizes acidic soils.
5. Epsom Salt: A source of magnesium and sulfur.
6. Azomite: A mineral product providing a broad spectrum of trace elements.
7. Sulfur: Used to decrease soil pH for acid-loving plants.

Miscellaneous Organic Amendments

1. Biochar: Improves soil fertility and water retention; helps sequester carbon.
2. Humic Acids: Enhance nutrient uptake and soil water-holding capacity.
3. Vermicompost: Richer in nutrients than traditional compost; produced by worms.
4. Wood Ash: Provides potassium and can raise soil pH.
5. Coffee Grounds: Add nitrogen to the soil and improve soil structure.

How to Use Organic Fertilizers

• Application: The application method depends on the fertilizer type. Some are mixed into the soil, while others are used as top dressing or made into teas for foliar or soil application.
• Combination: Combining different organic fertilizers can create a well-rounded nutrient profile for plants.
• Timing: Apply during active growth periods; avoid over-fertilizing, especially when plants are dormant.
• Soil Testing: Regularly testing soil helps guide the appropriate use and amount of fertilizer.

Organic fertilizers nourish plants and contribute to the garden’s overall ecosystem, supporting soil health, microbial activity, and sustainable gardening practices.