Mag-I-Cal® Plus for Lawns in Alkaline & Hard Soil 5,000SF Bag

Mag-I-Cal® Plus for Lawns in Alkaline & Hard Soil 5,000SF Bag

  • $32.00
    Unit price per 
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  • Natural soil food for lawns with alkaline soil
  • Loosens hard soils 
  • Promotes air and water penetration for deeper rooting
  • Helps to rapidly lower soil pH to increase grass nutrient absorption

Jonathan Green’s Mag-I-Cal® Plus for Lawns in Alkaline & Hard Soil contains sulfur and calcium sulfate dihydrate which lowers soil pH, is important to cell development, and is vital to many grass plant functions. Poor soil that is hard and compacted is often the problem when it comes to growing a great lawn. 

When soil is too alkaline and compacted, air, water, and nutrients cannot get down to the roots, and the grass will not grow properly. Lawns thrive in slightly acidic to neutral soil with pH levels between 6.2 and 7.0. In soils with pH readings of 7.0 to 9.5, weeds thrive and the grass becomes light green and spindly. Additionally, Mag-I-Cal® Plus helps to break up clay and compacted soils. This improves root penetration and promotes growth by increasing biological activity and releasing nutrients trapped in the soil.

When to Apply:

  • Best applied during the growing season when the soil is not frozen.
  • Safe to apply when seeding or sodding.
  • Spread the product on a dry lawn soon after mowing.


  • For best results, rake the lawn vigorously prior to application. 
  • Use a rotary or drop lawn spreader. To select the proper setting see the Spreader Settings section in the accordion below.
  • Apply around the perimeter of the lawn to establish a turning area. Then run the spreader back and forth within the area outlined by your first perimeter application. Always allow overlap to avoid gaps in coverage.   


  • To avoid staining, sweep any excess granules off of hard surfaces and back onto the lawn.
  • Irrigate the treated area after application for 15-30 minutes for the best results.
  • Once watered, wait a day to mow the lawn to give the product time to activate.
  • For soils with a pH higher than 7, repeat applications twice a year.


  •  18 lb Bag – 5,000 sq. ft. 
  •  54 lb Bag – 15,000 sq. ft. 

Fortified with:  Calcium sulfate dihydrate, humic acid, fast-acting gypsum, and humates

Can Be Used When Seeding:  Yes

Apply to Dry or Damp Lawn:  Dry

Safe for Children & Pets:  Yes

Application Temperature Range:  Minimum 45°F

When to Use:  Spring, summer or fall

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Product Label