Read the analysis on the package of your 4-4-4 fert, Terri. As long as it has iron in it, that will help. Chelated iron is better. But if it is granular fertilizer rather than something you would dissolve in a watering can it will take a lot longer to know if it's working. The minerals in greensand will help but it's mostly potassium and trace minerals although it does have some iron and silica. Again it will be very slow-release so it may take to the end of the summer for you to see results.
It's commendable to use organic products, but when you are looking for fast fix results, maybe not too practical. The organic fertilizers have all the same chemicals that the purified chemical ferts have, but in lesser concentration, and mixed in with a whole lot of stuff - basically impurities - that is fine for general long term plant health but not necessarily targeted for a specific result.
