Calphos Soft Rock Phosphate (5 lb bag)

Calphos Soft Rock Phosphate is a natural, slow-release source of phosphorus and calcium that enhances soil fertility and promotes strong root development. This finely ground mineral powder feeds plants gradually without the risk of leaching, supporting root vegetables, fruiting plants, and flowering ornamentals. This is the 5 pound bag.

At a glance

• Type: Natural soft rock phosphate amendment
• Form: Finely ground mineral powder
• Analysis: About 20% P2O5 (3% immediately available), 18% calcium
• Size: 5 lb bag
• Broadcast rate: 5 lb per 100 square feet on deficient soils
• Planting hole rate: 1 to 10 lb per hole by plant size
• Longevity: Supplies phosphorus and calcium up to 5 years

Best for

• Smaller gardens and raised beds
• Root vegetables, fruiting plants, and flowering ornamentals
• Orchards, flower beds, and general soil improvement
• Natural and organic-style soil building
• Long-term, slow-release fertility

How to use

Mix into the soil before planting at about 5 pounds per 100 square feet, or work 1 to 10 pounds into each planting hole depending on plant size. It also works as a top dressing through the season. The finely ground powder is readily absorbed and releases slowly, supporting phosphorus and calcium needs for several years.

About Grow Organic

Grow Organic supplies non-GMO seeds and natural soil amendments for growers who build fertility the sustainable way.