Does Miracle-Gro Go Bad? Garden Tips 2024

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Miracle-Gro has been on the market for decades and has gained great popularity among consumers. But the product also has haters who, amongst other things, claim that this so-called miracle plant food kills soil microbes. Presuming you want to use this particular water-soluble fertilizer, you’re probably wondering what its shelf life is and whether it’s likely to go bad. 

The shelf life of Miracle-Gro is officially three years. But it seems that it’s likely to be viable for as long as eight years. It may be even longer, as long as it hasn’t been opened. But even if it isn’t open, it could go bad if it hasn’t been stored correctly. For instance, it’s important to keep it in a cool dry place. 

What is Miracle-Gro?

Miracle-Gro fertilizer is a popular, water-soluble, all-purpose plant food. And it feeds the roots and foliage of plants relatively instantly. You can use it to feed just about any plants in your garden. These include all flowers, shrubs, trees, vegetables, and houseplants. 

And it certainly lives up to its “miracle grow” name. It starts to work instantly. If you feed your plants Miracle-Gro every 7-14 days during the growing season, you’ll get spectacular results. 

Nitrogen (24%) tops the listed active ingredients in Miracle-Gro, 3.5% of which is ammoniacal nitrogen and 20,5% urea nitrogen. Available phosphate is 8%, soluble potash 16%, boron 0.02%, copper 0.07%, iron 0.15%, manganese 0.05%, molybdenum 0.0005%, and zinc 0.06%. The fertilizer analysis of Miracle-Gro fertilizer is 24-8-16.

From this it may not be clear that this is a synthetic liquid fertilizer. In other words, it isn’t organic and the chemicals it contains are formulated in a laboratory. But not everyone cares. 

Manufacturers of Miracle-Gro

Miracle-Gro is manufactured by the Scotts Miracle-Gro Company, which until 2005 was called the Scotts Company. Doubtless, the change was because Miracle-Gro is the company’s leading product. 

But Scotts Miracle-Gro Company doesn’t only manufacture Miracle-Gro. It makes a multitude of other products including potting soil, which they describe as their “ultimate potting mix.” 

Scotts Miracle-Gro Company is undoubtedly the world’s largest marketer (if not producer) of branded consumer products for lawn and garden care. They also own the Roundup brand and exclusively market Monsanto products in North America and most of Europe. Both of these brands have a bad reputation with organic growers largely because of the toxicity of their products. 

While not relevant to whether Miracle-Gro goes bad or not, Scotts Miracle-Gro has had several run-ins with the law. For instance, in 2012, the company was ordered to pay $12.5 million in criminal fines and civil penalties for violating U.S. Federal Pesticide Laws

According to the government’s Environmental Protection Agency (EPA), violations include illegally applying insecticides to wild bird products. They also falsified pesticide registration documents and sold products that didn’t contain adequate warnings or cautions. 

Bear this in mind when you consider whether it’s safe to use Miracle-Gro or not. 

Is it safe to use Miracle-Gro?

Scotts Miracle-Gro tells us that it is 100% safe to use Miracle-Gro. They maintain that it is safe for humans to use because it doesn’t contain any carcinogens. 

They do, though, warn that it is important to use the product as directed. If you do this then it won’t burn your plants. 

Their Material Safety Data Sheet states that the product isn’t considered hazardous by the Occupational Safety And Health Administration’s Hazard Communication Standard. But it warns it may cause irritation if it comes into contact with your eyes or skin. 

While it is considered “practically non-toxic,” it is also possible that it may cause gastrointestinal tract irritation or irritation of the respiratory tract. 

Additionally, Scotts warn that inhalation via inhalation or through the skin may aggravate asthma. 

Their datasheet also warns users of Miracle-Gro to wear personal protective equipment (PPE). And they advise using “good housekeeping practices” by cleaning up promptly after using by vacuum or sweeping. 

Gardeners committed to organic gardening take safety challenges a lot more seriously. Most maintain that synthetic fertilizers are toxic. 

One of the major issues is that because Miracle-Gro contains so much nitrogen, it produces “off-chemicals” that harm the soil and everything that lives in it. 

How long does Miracle-Gro last?

Officially, the shelf life that Miracle-Gro offers is about three years, as long as it is kept in a cool, dry place. But, let’s remember that this product is water-soluble and needs to be mixed with water before use. 

Once it’s been mixed with water it takes the form of liquid fertilizer. And, after it’s been mixed with water, Miracle-Gro should be used within 24 hours otherwise it’s likely to lose its efficacy. 

But even if this water-soluble, miracle fertilizer hasn’t been diluted with water, it can deteriorate if it’s passed its official expiry date. This is more likely if the packaging has been opened.

If it hasn’t been opened, you can probably keep it for a good many more years. Some people suggest up to eight or ten years. There are even posts online that maintain that Scotts say it can last indefinitely. 

How do you know if Miracle-Gro has gone bad?

The reality of synthetic fertilizers is that they are formulated to last as long as possible. But if it doesn’t look right or smell right, there’s a good chance that it’s gone bad.

As long as synthetic fertilizers are stored correctly, the truth is that they will last a lot longer than organic fertilizers. So, as long as Miracle-Gro doesn’t get hot or freeze, it’s unlikely it will go bad.  

Dangers of using expired miracle gro

The biggest danger of using Miracle-Gro which has expired is its efficiency. It has been formulated to provide certain chemicals. But if it’s expired, there is no guarantee that it will provide the nutrients as claimed. 

An important caveat is not to increase the dose of Miracle-Gro if you think its impact will be reduced. The harm of a lesser dose will be a whole lot less than overdosing on the product. 


Miracle-Gro can go bad, but it’s unlikely that it will do so if you store it properly and use it within 3-10 years. It is more likely to lose efficacy than go bad. Usually, this will only happen if it’s been opened and stored in less than perfect conditions.

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