Iron Plus can be applied through fertigation, conventional spray, or root injection. It may
be applied alone or tank mixed with other products.✝ Shake well before using.
Greens & Tees:
Apply 3 to 6 oz. of Iron Plus diluted in 1 gallon of water per 1,000 sq. ft. (1 to 2 gallons diluted in 40 gallons of water per acre) every two weeks. To maximize performance, rates may be split into weekly applications.
Fairways, Lawns, Athletic Fields, and Other Turf:
Apply 6 to 12 oz of Iron Plus diluted in 1 gallon of water per 1,000 sq. ft. (2 to 4 gallons in 40 gallons of water per acre) per month. To maximize performance, rates may be split into weekly or bi-weekly applications.
Foliar Spray – Evergreens, Deciduous Shrubs, Trees & Palms:
Mix 1 gallon of Iron Plus in 100 Gallons of water and spray foliage to spray to the point of runoff. Best results will occur when applied to actively growing foliage during periods of high humidity and low plant stress (early mornings, late afternoons and cloudy days are preferable to hot, dry conditions).
Root Injection:
Dilution Rate: Mix 16 fl. oz. of Bio MP per 100-gallon tank. Apply as needed.
Operating pressure: 150 – 200 lbs PSI or ½ gal per 4 seconds
Area Method:
Trees: Apply 50 gallons of solution per 1,000 sq. ft. Inject 4-8 inches into the soil where the feeder roots typically occur. Begin injections 1-3 feet out from the trunk to avoid injury to large roots and work in a grid pattern away from the tree to within 2 feet of the drip line. Apply 1 pint (16 fl. oz.) of diluted solution per injection site at 18 inch spacing or ½ gallon (64 fl. oz.) of diluted solution per injection site at 3 foot spacing.
Shrubs: Apply 50 gallons of solution per 1,000 sq. ft. Inject one pint (16 fl. oz.) of diluted solution per injection site. Inject 4-6 inches into the soil with 18 inch spacing between injections.
DBH Method: Use the chart below to determine the volume of diluted solution to apply per inch of trunk diameter at breast height (DBH).
Tree Size (DBH Inch) |
Diluted Solution / Inch DBH |
Very Small (1-4”) |
0.5 gallon (64 fl. oz) |
Sm (5-7”) |
1 gallon |
Sm – Med (8-11”) |
1.5 gallons |
Medium (12-15”) |
2 gallons |
Med – Lrg (15-19”) |
2.5 gallons |
Large (20+”) |
3 gallons |
✝ Compatibility: perform a standard jar test to check compatibility with other products before mixing.