Organic soil amendments for home gardens

Compare compost, biochar, worm castings, and other organic soil amendments. See what they do for your garden and where to buy them.

All types Biological Carbon amendment Mineral & micronutrient Mineral conditioner Nitrogen source Organic matter pH adjustment Phosphorus source

Alfalfa Meal

Nitrogen source

Ground alfalfa providing nitrogen, triacontanol, and organic matter.

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Biochar

Carbon amendment

Charred biomass that holds nutrients and water while improving soil structure long-term.

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Blood Meal

Nitrogen source

Dried blood high in nitrogen for leafy growth.

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Bone Meal

Phosphorus source

Ground animal bones providing slow-release phosphorus and calcium.

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Coco Coir

Organic matter

Coconut husk fiber improving aeration and water retention as a peat alternative.

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Compost

Organic matter

Decomposed organic material that improves soil structure, water retention, and microbial life.

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Gypsum

Mineral conditioner

Calcium sulfate that improves soil structure without changing pH much.

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Kelp Meal

Mineral & micronutrient

Dried seaweed meal supplying micronutrients, growth hormones, and organic matter.

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Mycorrhizal Inoculant

Biological

Beneficial fungi that colonize roots and extend nutrient/water uptake.

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Rock Dust

Mineral & micronutrient

Crushed volcanic or mineral rock adding slow-release trace elements.

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Sulfur

pH adjustment

Elemental sulfur used to lower soil pH in alkaline soils over time.

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Worm Castings

Organic matter

Vermicompost rich in microbes, humus, and plant-available nutrients.

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Research links only. Verify products and application rates for your soil and plants.