Carefully pour out the liquid without shaking. If there is a dark brown sediment left at the bottom then (some) iron has separated from the solution. Means it would not be as effective. In any case it will not harm the plants but there may be not much iron left in solution.

If you see sediment then it means that iron has converted from soluble Ferrous form to insoluble Ferric form.

would vinegar liquefy the iron

Thank you for the break down and explanation. My knowledge of such things is woefully lacking. I did have iron deficiency with using hard water. Now that I water exclusively with rain water, I see it much less. I might add a smidge of vinegar to the mix next time

I did end up dumping the old mixture. Before I shook it, there was a lot of sediment on the bottom. It all mixed together after a few good shakes, but it’s so easy to just make fresh. I have plenty and I use it sparingly.

Chelates are also photosensitive and degrade with exposure to the sun. Both the dry form and the liquid solution should be stored in light tight containers and used at dusk. For best results in strongly alkaline soils the EDDHA iron chelate is recommended. Unfortunately it is the most expensive of the iron chelates. I use about 40ml of vinegar to 10lt of solution when preparing the solution for drenching. I always prepare the solution just before use.

I had know idea I was supposed to use it at dusk. I'll do that from now on. I don't spray very often, so I'll always mix fresh from now on. Thank you all for your input. I never took chemistry.

thank you; I have not previously seen the info that it is photosensitive.

Alanna

I took chemistry and I can assure you that you didn't miss anything