Espoma Iron-toneEspoma Iron Tone for Sale Online Espoma Organic Iron Tone Plant Supplement is for use on lawns, flowers, vegetables, evergreen & ornamental shrubs, berries, citrus, shade, ornamental & fruit trees. Use in the early Spring, or any time during the growing season where iron chlorosis (yellow leaves) exists. Organic fertilizer & Iron supplement Fast acting iron supplement Turns yellow to green naturally Will not stain concrete surfaces