Does Bottled Fertilizer "Go Bad"?
 

In the process of cleaning up my orchid area so I can get seriously into growing again, I discover that I have, shall we say, a few bottles of various types of fertilizer of unknown vintage.

None of them have any sort of expiration date stamped on the bottles, and they've been stored (well-sealed) in a cool, dark area. Should I just toss them and plan on buying new? Or are they conceivably still "good"?

Fertilizer keeps for years. I would think they are still good for use.

Excellent! Thanks, trdyl!

I Had the same question.. Thanks

actually I believe it depends on if the fertilizer "salts" have precipitated out of solution or not ....You know shake the bottle and the liquid seems to have chunks sloshing around the bottom of the bottle....

liquid types can do strange things

These are all in semi-transparent bottles, so I can see any solids that collect on the bottom. They all go back into solution when I shake the bottle.

That's a good detail to know, though. Thanks!

I think certain liquid fertilizer percipitate especially when the temps get a little low

How about a add water powder fertilizer... Would that still be good after a few years..

They do not go bad unless they have gotten wet and hard and usually even then are just bricks lol and need broken up. Th liquid alows the chemicals to react and actually precipitate out and usually they dont like to redissolve into solution then ...so you get a unkown quantity when mixed.

I like powder (dry) fertilizer best. The only caution is it tends to be stronger. I would suggest starting with a quarter strength for a while then go from there. In addition water your plants without fertilizer first to also prevent burn.