Please give me more information about this product. The only Hi-Yield Iron Plus product I can find is one where the 'plus' is 11% ammonium nitrate (and sulfur, as well). If that's what you are using, then you will need to follow directions carefully regarding the amount to place in each container.

And, NO, this is not a soluble fertilizer that can be dissolved in water with predictable results.

Thank you so much for that advice. Yes, it is that product. I guess I'll put in the time to apply it as directed.

And don't forget that high Nitrogen percentage. This is not a product that you can use very often, especially in containerized plants.