New FREE shipping options & flat rates as low as $7.99! Details

Calphos Soft Rock Phosphate - Regular Powder (50 lb)
Calphos Soft Rock Phosphate - Regular Powder (50 lb)
Calphos Soft Rock Phosphate - Regular Powder (50 lb)
Brand: Calphos
Item Number: F2101

Calphos Soft Rock Phosphate - Regular Powder (50 lb)

Colloidal Phosphate for Slow-Release

Listed for Use in Organic Agriculture by the Organic Materials Review Institute Approved for Organic Agriculture by the California Department of Food and Agriculture

Regular price
In Stock
Sale price
Ships from Northern CA.

What You May Need:

Shipping calculated at checkout.

Quantity must be 1 or more


The best natural source of phosphorus and calcium. It is comprised of the bony structures of prehistoric marine creatures mined in Florida from the best deposit in the country. An immediately available and a long-term source of phosphorus. Not the same as the hard rock phosphate, sold by most nurseries and farm suppliers, which is not nutritionally as readily available.

  • Averages 20% P2O5 (3% immediately available), 20% Ca
  • Soft Rock Phosphate should be applied and worked in prior to planting
  • Use at 5 lb/100 sq.ft. or 1 ton/acre on phosphate deficient soils, less on fertile soils
  • Trees and perennials, use 1-10 lb per planting hole, depending on plant size
  • Supplies P and Ca for up to 5 years after application, depending on the crop



    Organic Status :
    Approved for Use in Certified Organic Agriculture
    Animal-Based : No
    Fertilizer Type : Powdered/Granulated/Meal
    Major Nutrients : Calcium
    Major Nutrients : Over 3% Phosphorus
    Major Nutrients : Trace Minerals
    Nutrient Release Rate : Long-term (4+ Months)
    Use as Foliar : No
    Organic Certifier: OMRI, CDFA

    Useful Information


    Does not qualify for Flat Rate Shipping.

    Cannot be combined with other items in a package, due either to its size or manufacturer packaging.

    Shipping Weight: 55.0 lb

    Dimensions: 20.0"L x 13.0"W x 4.0"H


    Customer Reviews

    {"rating"=>Metafields::MetafieldDrop, "rating_count"=>15}
    Back to Top