Return to the House Plants Forum | Post a Follow-Up

 o
How long does fertilizer keep?

Posted by watergal z6/7 Westminster, MD (My Page) on
Sun, Mar 25, 07 at 14:40

Specifically, the timed-release pellets. I have some Nutricote and some Peters in the shed that have been there for, oh, 2 to 4 or more years. The shed is under the deck in a corner formed by the house, so it's shaded and somewhat protected, but it has no climate control.

Will the temperature extremes have taken enough of a toll on the fertilizer that I should just chuck it? There's not that much left, but I hate to waste it if it's still OK.


Follow-Up Postings:

 o
RE: How long does fertilizer keep?

It is my understanding that fertilizers are generally okay for about a year, but they start to deteriorate after that. The deterioration would be faster in a warm and damp environment. If it were mine, I would not take a chance with it.

Hmm, that reminds me I have some closet cleaning to do myself!

Will Creed
Indoor landscaper


 o
RE: How long does fertilizer keep?

See if there's a toll free number on the packaging. If not, you can find an information number on line. They will be able to answer the question for you.


 o
RE: How long does fertilizer keep?

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Mar 25, 07 at 17:21

The concept of CRF is a simple one: Manufacturers start with a granular soluble fertilizer, then coat it with a semi-permeable polymer membrane. As water passes through the membrane into the fertilizer core, nutrients within the fertilizer go into suspension (dissolve). Because the concentration of nutrients is higher inside the membrane, nutrients begin to diffuse out through the membrane by a natural process called osmosis. The osmotic release will continue until such time as there is no longer a nutrient concentration difference across the membrane, effectively, until nutrients within the CRF pellets are exhausted. So, CRF actually never goes bad. Even if it's exposed to some moisture and a portion of the fertilizer leaches out from the granules, only a small volume of fertilizer contained within the pellets is affected. As soon as the solute concentration in the area immediately surrounding the pellet equalizes with the concentration inside the pellet, fertilizer inside the pellet can no longer dissolve and pass through the membrane.

Al


 o
RE: How long does fertilizer keep?

  • Posted by watergal z6/7 Westminster, MD (My Page) on
    Sun, Mar 25, 07 at 21:40

Al, that makes a great deal of sense. Thank you! They should have stayed dry, so I'm good to go.

How about a water soluble granular fertilizer such as MiracleGro. How long will that store?


 o
RE: How long does fertilizer keep?

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Mar 25, 07 at 21:50

Indefinitely. Even if it gets all gunky from absorbing water from the air, it will still be equally effective as new product, though perhaps not as convenient to use. If it turns to a semi-liquid, remember to measure out less product because there will be little air in what you're using. This would, in effect, make a higher concentration using the same volume (all product - no air).

Al


 o
RE: How long does fertilizer keep?

  • Posted by watergal z6/7 Westminster, MD (My Page) on
    Sun, Mar 25, 07 at 22:12

Thanks again, Al! I've never had it get all gunky, just a tad damp, like slightly damp sand. You've saved me from buying a lot of unnecessary fertilizer!


 o
RE: How long does fertilizer keep?

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Mar 25, 07 at 23:05

Indefinitely. Even if it gets all gunky from absorbing water from the air, it will still be equally effective as new product, though perhaps not as convenient to use. If it turns to a semi-liquid, remember to measure out less product because there will be little air in what you're using. This would, in effect, make a higher concentration using the same volume (all product - no air).

Al


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the House Plants Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here