It is well known that ferrous sulfate cannot be stored in the air for a long time. Because ferrous sulfate has a strong redox property, it will react with oxygen in the air after being placed in the air for a long time, then hydrolyze in the air, and slowly oxidize to ferric sulfate or ferric hydroxide, and its ferrous sulfate ion divalent iron will be slowly oxidized to trivalent iron (Fe3 +). The color of ferrous sulfate will change from light green to yellowish brown. If ferrous sulfate solution is used to water flowers, the modified ferrous sulfate solution will also be yellow with precipitates. Solid ferrous sulfate will form yellow block after modification, and the chemical properties will change too, so the use effect will be greatly reduced. Therefore, the first way to extend the shelf life of ferrous sulfate is to store it in a dry and cool place to avoid excessive contact with the air and keep away from oxidants. Generally, the shelf life of ferrous sulfate can be extended about one month due to proper preservation.