Oyster Shell Flour (50 lb)

Naturally raise soil pH and boost calcium levels with Pacific Pearl Oyster Shell Flour — a high-quality, organic rock dust fertilizer made from ground marine oyster shells. Ideal for gardens, orchards, trees, and compost, this premium soil amendment helps build stronger plants and healthier soil, season after season.

Key Benefits

• 96% calcium carbonate for pH adjustment and calcium enrichment
• Improves soil tilth and nutrient uptake
• Strengthens plant cell walls and promotes root growth
• Variable particle sizes for both fast and slow nutrient release
• 100% natural and OMRI Listed for certified organic gardening
• Also great for bocce ball courts and landscape use

Application Rates

For best results, apply in early spring or fall and water in well after application.

Why Choose Our Oyster Shell Flour?

• Made from clean, ground oyster shells
• Excellent alternative to lime — with longer-lasting results
• Enhances compost quality when mixed in
• Improves soil structure in sandy, clay, or compacted soils
• Bulk 50 lb bag perfect for gardens, orchards, or landscaping projects

How It Works

Oyster shell flour is a natural source of calcium carbonate, a key mineral that raises soil pH in acidic conditions and strengthens plant cell walls. The slow-release nature of the coarse and fine particles means nutrients stay available over time, helping plants absorb fertilizers more efficiently and grow healthier, more resilient roots.

Great For:

• Organic vegetable gardens
• Fruit trees, berry bushes, and vineyards
• Flower beds and landscaping
• Compost and soil mix improvements
• Bocce ball court base material

Support Sustainable Soil Health

Using natural soil amendments like oyster shell flour reduces dependence on synthetic chemicals, supports microbial life, and improves long-term soil fertility — making it an essential tool for regenerative and organic growers.

For any other soil needs please check our soil amendments collection.

For fertilizing and plant nutrition, our collection of fertilizers will meet your needs.

⚠ Warning: This product or its packaging has a CA Prop 65 Warning