Are your plants yellowing despite a correct watering program? You may need to add iron to your soil. Copperas Iron Sulphate from Hi-Yield relieves iron deficiencies in the soil and increases acid levels. For trees: apply 1/2 lb. per inch of trunk around drip line. For shrubs: apply 1 lb. per 2 ft. of height. Caution: Will stain concrete and pavement.

As it's name suggests, Dr. Iron contains 22% non-staining iron, along with 55% sulphur, to boost iron levels and reduce soil pH. Use non-burning Dr. Iron on lawns, flowers, vegetables, trees and shrubs.

Spread 3 1/2 lbs per 1000 sq. ft. of dry powder on area to be treated. Follow with deep thorough watering to activate it.

Epsom salt is actually magnesium sulfate, a blend of minerals plants need for a stronger root structure and to facilitate the uptake of chlorophyll. Use as an ingredient in organic fertilizer, and in alkaline soils where magnesium deficiciences occur. Recommended by many master gardeners and landscape professionals.

Texas Green Sand is glauconite - a naturally occuring mineral rich in iron. Formed from ancient seabed deposits, Texas Green Sand helps hold moisture in the ground so that it is released more slowly. When incorporated into clay soils its friable nature works to decrease compaction. Its texture and chemical composition also make it an ideal amendment for sandy soils where it adds iron and potassium in a slow release form.