Jacks Classic petunia feed was originally developed for the professional grower. Designed for plants that are inefficient when taking up iron up from their root zone, this special formulation provides essential amounts of iron needed for consistent plant growth. Contains an enhanced micronutrient package that includes 3 forms of iron and extra magnesium that will produce lush green plants in any growing condition. This low phosphorus formulation keeps plants fuller. Petunia feed is especially effective in hanging baskets containers that are watered often.