Liquid Iron Plant Growth Supplement Liquid Iron Plant Growth Supplement is most effective when plants are growing rapidly and least effective when dormant or suffering from stress. It is also compatible with most pesticides and fertilizers, with the exception of amine formulations and high phosphate fertilizers. To use, apply 3-5 times a year to promote vigorous growth and dark green color. It also corrects iron deficiency. The supplement is ideal for use on turf, flowers, shrubs, lawns, plants and trees. Product contains magnesium 50%, total boron 02%, total Copper 25%, total Iron 5 00%, total Manganese 25%, total Zinc 50%, and sulfur.Size:Quart About Us We specialize in all types of equestrian equipment and apparel for both the English and Western rider. Shop with us and you will find everything you need for your horse, barn, farm, tack shop and shows – we even have pet, garden & pond products too! Return Policy 30 day returns. Buyer pays for return shipping.