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What is the shelf life of Miracle-Gro powder?

Posted by nick_b79 z4 MN (My Page) on
Sat, Jan 12, 08 at 19:29

My dad has accumulated about 15-20 lbs of powder Miracle-Gro fertilizer from various auctions he's gone to in the past few years. Most of them have been opened, and he's stored them down in our cellar (~65F year-round and high humidity). I'm pretty sure that the nitrogen present in them has broken down, but by how much? Some of these may be a decade old by now. The potassium and phosphates remain the same over time, though, right? If nothing else, I was planning on slowly adding it to the compost pile so that it gets put to use.

Thanks.


Follow-Up Postings:

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RE: What is the shelf life of Miracle-Gro powder?

Shelf life - about the same as nuclear waste.

The powdered product should last virtually forever according to the U of MN Ext. Not so sure about liquid forms when kept, say in an unheated garage and subject to freezing and thawing, etc. That could result in separations or chemical changes over time.


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RE: What is the shelf life of Miracle-Gro powder?

But Miracle Grow is a salt and might not be the healthiest thing for your compost.

Karen


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RE: What is the shelf life of Miracle-Gro powder?

Some fertilizer stored for a long period of time become ecplosive. It is not a good practice.


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RE: What is the shelf life of Miracle-Gro powder?

It's an odd question for this forum. Miracle Grow isn't healthy for soil. Is there a way you can safely dispose of it?


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RE: What is the shelf life of Miracle-Gro powder?

I think it is rather faddish to exaggerate the negatives of various fertilizers - I feel there definitely are negatives and these are often definitely exaggerated. If I had it I would dissolve it and then I would toss it sparingly on whatever was available.

I would invite those who want to participate in the fad to do something else with it.


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RE: What is the shelf life of Miracle-Gro powder?

Sorry if this was the wrong forum to post this on, but I didn't know which other forum to post this question on.

Why is Miracle Gro (at the levels I'd be adding this stuff) bad for soil? This will be used up between two very large vegetable gardens (20 ft x 50 ft) so the application would be very light if spread directly onto the soil.

Thanks for the help so far.


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RE: What is the shelf life of Miracle-Gro powder?

Sorry if this was the wrong forum to post this on,

This is the right forum. I've seen and even been caught in this before. The people on this forum are very often the same ones participating in the organic forum. There is a tendency to get the two confused when you're just reading away. This is not the organic forum so your question is perfect.

Personally I'm an organic kind of guy and would leave the Miracle Gro on the shelf indefinitely or until someone came along and asked if they could borrow it. The reason Miracle Gro is thought to be bad for the soil is that it is not food for soil microbes. Soil microbes "eat" stuff that lands on the ground. This is the decomposition process that we call rotting, "going bad," mold, and many other terms. When that happens in the soil, the byproducts of all that decomposition is Mother Nature's plant foods along with Mother Nature's "drugs" that help the plants fight off disease. Penicillin, for example, comes from soil microbes. There are other chemical materials that help plants.

The salty chemicals in Miracle Gro are not in any of the food groups (protein, vitamins, minerals, or carbohydrates). Thus while the plants will benefit briefly from the chemicals, the soil microbes which normally provide plant food, will suffer. So the best reason I can think of that Miracle Gro is bad is that it is not good for soil microbes. Whether it kills them has not been proved in anything I've read anywhere. As with anything, the dose makes the poison.


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RE: What is the shelf life of Miracle-Gro powder?

It keeps pretty much forever. I use it on lettuce and cilantro that I grow indoors with plastic window boxes, both plants require a lot of nitrogen to grow quickly. I reuse the soil year after year, although it might be more accurate to call it "growing medium", not soil.

I don't know how big your compost pile is, but I should think it wouldn't have much of a negative effect if you tossed it, bit by bit, into the compost, over the course several cycles. Dumping the whole 20 lbs at once might be a bit much.


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RE: What is the shelf life of Miracle-Gro powder?

Call your local fire department and ask them what they think about old fertlizer.

I dont have a thing against new fertilizer.


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RE: What is the shelf life of Miracle-Gro powder?

  • Posted by jean001 z8aPortland, OR (My Page) on
    Sun, Jan 13, 08 at 20:00

Miracle-Gro is fine to use according to directions. It isn't explosive, not under any conditions.

It's a fertilizer. So, that's an excellent use for it.

Applied according to the directions, it won't harm either your plants nor your soil.

All fertilizers -- whether organic, natural, or synthesized -- are "salts" when they are in a form available to plants. "Salts" defined in simplest terms, simply means that it dissolves in water.


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RE: What is the shelf life of Miracle-Gro powder?

Compared to the 20 pounds of gunpowder in my closet, and the 1000 gallons of diesel fuel my dad has stored at the farm for the tractors, a few containers of old Miracle-Gro really doesn't terrify me all that much :-) Thanks for the concern, though.


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RE: What is the shelf life of Miracle-Gro powder?

Some interesting info except the worry of storing it. Wouldn't waist my time buying it though. Garden plants will get big and bushy from the nitrogen but you won't have a large amount of vegetables like with regular compost.


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RE: What is the shelf life of Miracle-Gro powder?

There are many varieties of Miracle-Gro and I would go through the bags and put like mixes together. A chemical fertilizer such as MG is fine for containers as the soil in them is not permanent and will eventually be discarded. For my garden I do not use chemicals as they are not compatible with the soil life. Al


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RE: What is the shelf life of Miracle-Gro powder?

"The reason Miracle Gro is thought to be bad for the soil is that it is not food for soil microbes."

This isnt true. Microbes might not use the elements specifically for fuel, but they use them to carry out biological functions just like every other plant or animal.

"The salty chemicals in Miracle Gro are not in any of the food groups (protein, vitamins, minerals, or carbohydrates)."

This isnt true either. The minerals in fertilizers are minerals and are used by plants to make proteins, vitamins, and carbohydrates. As I said above, microbes use them as well. The deleterious effects of chemical fertilizers are way way overblown. Yes, if you inject anhydrous ammonia into the plow layer of your soil you are going to wipe out the microbe population and essentially sterilize the soil for a couple of weeks. If on the other hand you spray your yard with miracle grow in solution you are only going to stimulate microbes that will use the available nitrogen to burn carbon (organic matter) for fuel.

" "Salts" defined in simplest terms, simply means that it dissolves in water."
That is not a good definition. Many salts are considered insoluble such as phosphate rocks. A better definition is that a salt is a cation (positive charge because it is missing an electron) and an anion (negative charge because it has an extra electron) joined together (the positive and negative charges being drawn together). Table salt for example is a sodium cation bound with a chloride anion. Potassium sulfate, ammonium nitrate, etc are soluble salts that are used for fertilizers because they are composed of elements that plants use as nutrients.


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RE: What is the shelf life of Miracle-Gro powder?

How long any synthetic fertilizer would be okay would depend on its exposure to moisture. The unopened packets are probably as good as the day they were manufacured while the opened packets will not be. While I have found that this product is not worth the expense there are people that find it necessary to use it, and as Dave has already stated discussing it here is okay.


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