To use Ironite fertilizer, spread the granules on the soil, and water it immediately afterward. If the soil is too alkaline, use the liquid Ironite fertilizer. Also spray it on the grass so the leaves can absorb some of the iron.
Plants that are deficient in iron suffer from chlorosis, or yellowing of the leaves. Iron is generally available in the soil, but most is not in a form that the roots can readily absorb. Iron also becomes unavailable when the soil has a pH above 6.5. The iron in Ironite is in a form that is readily absorbed by the plants, so it resolves the problem of chlorosis. A 1,000-square-foot lawn requires only 0.7 ounces of iron. Excessive amounts of the mineral can cause the leaves to have a black-green color. Ironite fertilizer contains 4.5 percent iron by weight, so the recommended amount of Ironite per 1,000 square feet is only 1 pound. After the application of iron fertilizer, turfgrass remains green for two to three weeks during cool, wet periods and for several months during cool, dry periods. Therefore, Ironite can be used about four times per year but not more than 10 times, depending on the season.