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Expired Fertilizer?

Posted by hopefulauthor z5IL (My Page) on
Wed, Apr 2, 08 at 17:29

Does anyone know if fertilizer loses strength, or will harm plants, if old and possibly outdated?
A few yrs ago, I bought several boxes of fertlizer at a super discount price..Enough, I thought to last several years..
Each box was 1.99..One was All Purpose, the other for Acidic Plants..
The containers don't have expiration's possible these fertilzers were sitting on a nursery shelf for years..Plus I've had them 3 or 4 years now..
Does fertilizer stale? Spoil? If anyone has any idea, please HELP..Should I toss it? Thanks, Toni

Follow-Up Postings:

RE: Expired Fertilizer?

I had wondered that same question before and did some reading on the subject. From what I have read, they don't go bad, that's ANY kind of fertilizer, liquid, powder, or timed release.
I did throw away a small bag of some of the blue soluable stuff last year because it became kinda wet from me sticking my just washed hand in the bag, it was literally a melted mess, but, it was probably still good.

Billy Rae

RE: Expired Fertilizer?

I found this online...

"With liquid fertilizers, there might be some crystallization over time. The solubility of fertilizer salts increases with increasing temperature, so heating a container of liquid fertilizer (by putting it in a pot of hot water) should dissolve any crystals.

Otherwise, nitrogen fertilizers can degrade through loss of ammonia (a gaseous nitrogen compound) to the atmosphere. The ammonium compounds which are used as nitrogen carriers break down very slowly unless mixed with alkaline substances, but they may lose some weight and value over prolonged storage ... especially if their container is not well sealed.

Some organic fertilizers can become moldy. Their nutrients may blow away as spores."

Hope this helps!

RE: Expired Fertilizer?

I saw that same thing (above) about degrading of fertilizer, but everywhere else the articles would say it doesn't, so who's to say for sure???
Nothing last forever and I'm sure there is some "degrading" over time, but how much degrading would be too much? I guess your plants would tell you.
I have plenty of old fertilzer around here and they still seem to be doing an ok job of it.

Billy Rae

RE: Expired Fertilizer?

Oh My God, my thread reappeared..that IS
I wonder if the thread regarding Colocasia mysteriously returned..have to check it out..LOL..strange.

Billy, I know what you mean about powdered fertilizer..I opened the plastic bag it comes in, (for acidic plants) and found dark blue speckles..perhaps it got wet during handling, so don't want to chance it..Afterall, if you or anyone here read up on fertilizers, they say never use mixed fertilzer that's been sitting in water more than 8 hours..or less..
I tossed it, so don't have to worry..We went to Ace Hardware, purchased new ferts..
I don't know if old fert would harm a plant, but at the least, may lose nutrients.. It takes 2-3 days to fertilize my plants..why waste time using something that's not going to work?? Or worse, harm/kill plants?

Chan, your post is interesting..I agree. Most of my ferts are powder though..The only liquid ferts I've seen are those by, I believe, Shultz..the directions say, use 7 drops per gallon of water, 'everytime' you water..sounds like they're trying to push their product, instrucing people to use every watering. Wouldnt you think??? Toni

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