Ferrous Sulfate (Iron Sulfate) FAQ

1. What is the application rate of Ferrous Sulfate for lawns (St. Augustine grass)?

We would recommend using 2-3 Oz. (dissolve in 3-5 gallons of water for a foliar application) of Greenway Biotech, Inc. Ferrous Sulfate (20% Iron (Fe) ) per 1000 sq.ft. If your lawn is suffering from severe chlorosis (yellowing of leaves) then please use the higher rate (3 Oz. / 1000 sq.ft) and if your lawn is relatively healthy then please use the lower application rate (2 Oz. / 1000 sq.ft.)


2. How long does it take for Ferrous Sulfate to lower the soil pH level?

It really depends on a few factors and it is not the same in all circumstances. For example, it takes longer to lower the soil pH level from 8 to 6 compared to 7 to 6. However, in most cases, you should get your desired pH level after 2-3 weeks.


3. Can I use Greenway Biotech Ferrous Sulfate (Iron Sulfate) to make Iron Gall ink?

Yes, one of the ingredients to make Iron Gall ink is Ferrous Sulfate and you could certainly use Greenway Biotech's Ferrous Sulfate to make Iron Gall ink.