Fertilizer shelf life

[bellini girl]

Expiry dates for water soluble fertilizer. How old is too old. Had some lying around for a while and wondered if it is still good

[RJSquirrel]

if light heat or moisture hasn't broken it down into a puddle of mud its fine...its the liquid stuff you get in the brown bottles that has limits. it comes in brown bottles bec light breaks it down. my water soluble stuff turns to liquid if I leave it out. hard to measure when that happens.

all things considered though if its that old you got to think about it, go buy some fresh. please

[Bud]

I agree...just buy a fresh bottle....you might not know what happened in the duration when it was first opened and the present ....it might have decomposed or lost its potency

[bellini girl]

Thanks guys. I'll just chuck that lot out and get new

[Ray]

I will also add that if you have a bottle of liquid fertilizer lying around that is that old, you have not been feeding your plants enough!

[Cym Ladye]

Originally Posted by Ray

I will also add that if you have a bottle of liquid fertilizer lying around that is that old, you have not been feeding your plants enough!

Touche Ray!!

Cym Ladye

[lostonthebeach]

Originally Posted by bellini girl

Thanks guys. I'll just chuck that lot out and get new

Even the old stuff can be used on lawn, trees, and some shrubs.

[skipper]

Try some of the MSU fertilizer from Ray, it's great stuff.

Dale

[daveh_sf]

Some of the simple ionic salt compounds of fertilizers have a very long if not indefinite shelf life. But others such as ferrous salts can oxidize to ferric salts when exposed to air. More complex molecular compounds like iron EDTA, vitamins, or hormones can gradually break down when exposed to air, light or heat. In general you can assume that an unopened package will be good for perhaps 5 years if stored in a cool dark place, and much less after it has been opened.

[LavendarSunset]

I always wonder how long the fertilizer has been sitting around before I buy it. It would be nice if the manufacturers would put a "best if used by" date on the packaging.

Being able to buy fertilizer in a small quantity would be nice, too. If you don't have a greenhouse full of orchids, or a large quantity in your home, even if you feed them on a regular basis it still takes a long time to use the fertilizer up.