Skip to Content

Does Miracle-Gro go bad? The Facts

After researching whether Miracle-Gro goes bad, I realized this is probably a popular question among gardeners. So I decided to put my findings into this detailed article.

Miracle-Gro has a relatively long shelf life but will eventually go bad. Usually, at around the three-year mark, it will not be at its best original state anymore. Its vitality as a fertilizer is also affected by certain other factors such as how the Miracle-Gro is stored and external factors.

In the following few sections, we shall talk about the different variants of Miracle-Gro and the steps to take to ensure proper storage of them to make their shell-lives last.

What is Miracle-Gro?

Miracle-Gro, from their website, is stated to be a company; specifically, the Scotts Company is renowned for making quality gardening products. Their product ranges from fertilizers, soils, tools, and even plants.

Essentially, the aim of Miracle-Gro, especially their potting mixes is to provide plants with all of the necessary nutrients and ingredients that it needs to thrive in an indoor environment.

The miracle-gro stated for the rest of this article will be their ‘plant food’ variant fertilizer. Most are water-soluble and created to target and foster specific plant types like vegetables, lawns, flowers, and even for weed protection.

Many have been utilizing this for all-around garden care, so today, we will be tackling the question of just how long the staying power and vitality of these products are before going bad.

Things that impact whether a Miracle-Gro goes bad

This section will look at the various factors determining whether Miracle-Gro is still ok to use or whether it has no longer fit for purpose.

It's Ironic I Got Stressed Creating... x
It's Ironic I Got Stressed Creating A Well Being Garden

How the Miracle-Gro has been stored affects is lasting power

The single most significant deciding factor is how the Miracle-Gro has been stored since it was manufactured. If it has been kept in cool and dry conditions and is unopened, there’s a good chance it’s as usable as the first day it was mixed. If it has been exposed to heat, the Miracle-Gro will be good to use for a much shorter period.

If the bag has been opened, this is likely to allow moisture to get in. This results in the slow-release fertilizer deteriorating and eventually dissolving. If plants don’t use the nutrients from the fertilizer, it will simply dissipate into the atmosphere.

As there’s no way of telling how the Miracle-Gro was stored before it came into your possession, it’s best to be cautious and use it within a year or two.

Different Miracle-Gro variants also have differing shelf lives

Another impacting variable is the type of Miracle-Gro you have. Potting mix, which has fertilizer added, is likely to stay good for years, providing it has been stored correctly, and the bag is left unopened.

If you have liquid Miracle-Gro, it runs the risk of crystallizing over time as these products generally have a shelf life of 3 years.

Again, this all depends on how they’ve been stored. More about the storage considerations and how best to do it will be in the following few sections.

Different Miracle-Gro variants

As seen on their website, the plant food options for Miracle-gro target specific problems and plant types, and in the following few sections, we will be talking about how to deal with said variants.

Miracle-Gro liquid and rectifying when it crystallizes

If liquid Miracle-Gro has started to crystallize, the tried and tested method when rectifying this problem.

Because fertilizer salts increase in terms of solubility as the temperature gets higher, you can heat the liquid fertilizer container by submerging it in hot water, which should cause the crystals to dissolve.

The degradation process of nitrogen-based Miracle-Gro is caused by a gradual loss of the compound ammonia. These are used as nitrogen but break down gradually if they are not mixed with alkaline substances.

Does Miracle-Gro potting soil go bad?

To definitively answer whether Miracle-Gro potting soil goes terrible, we need to look at the ingredients it contains.

There are some variations of Miracle-Gro potting mix which may contain additives specifically to benefit certain plants. On the whole, though, the following are the most common ingredients in Miracle-Gro potting soils.

Sphagnum MossAmmonium Nitrate
PerlitePotassium Sulfate
CompostAmmonium Phosphate
Calcium Phosphate

More about them will be described in detail in the following few sections.

Sphagnum Moss in the Miracle-Gro potting Soil

This form of moss originates in boggy conditions, thanks to its absorbent nature and shallow roots. In appearance, it is a light green color and has a complex system made up of capillaries.

These porous capillary tubes give the Sphagnum Moss its water-holding ability.

Sphagnum moss is commonly used for gardening purposes, notably for improving the moisture levels in the soil.

It is beneficial for preventing soil from drying out when indoor gardening. Another benefit of this Miracle-Gro ingredient is that it contains a chemical known as sfagnol, which stops bacteria from growing e to its antiseptic makeup,

Perlite in the Miracle-Gro potting Soil

Another common addition to Miracle-Gro potting mixes, Perlite is a form of glass naturally produced in volcanoes. Remarkably, it can expand in volume by up to 20 times.

For gardening purposes, perlite is brilliant for aerating the soil and retaining moisture, especially indoor gardening. Another great thing about perlite is that it is void of weeds and has a neutral pH level that plants love.

Compost in the Miracle-Gro potting Soil

A prominent ingredient in Miracle-Gro potting mix is every gardener’s best friend, compost.

This mixture of decomposing organic matter, which is compost is a vital part of Miracle-Gro, gives nutrients to plants in a slow-release manner.

It also increases the number of helpful organisms in the soil and makes it better at holding moisture. Plants thrive in good quality compost due to the long-term supply of nutrients it provides them with.

Calcium Phosphate in the Miracle-Gro potting Soil

Calcium phosphate is frequently added into potting mixes because plants need ample calcium for their chromosomes to develop appropriately and for cell division.

It is also helpful at staving off numerous diseases.

Ammonium Nitrate in the Miracle-Gro potting Soil

An excellent source of nitrogen, ammonium nitrate is another commonly found ingredient in Miracle-Gro potting soils.

Nitrogen is invaluable to plants due to its role in the production and development of vital amino acids.

Nitrogen is actually one of the most critical nutrients for plant growth, as further expounded in my recent article on essential nutrients for plants.

The report covers the differing nutrients one should look into for plant growth, how to look at the nutrient ratios when buying fertilizers, and it also covers how nitrogen, in particular, can be challenging to give to plants due to how difficult it is for plants to access it naturally through nature.

Nitrogen considerations for plants

Due to this, more gardeners have opted to buy organic nitrogen to supplement plant growth. However, in large doses, nitrogen can actually be harmful due to the rapid rate it encourages plants to grow at – so not a lot of ammonium nitrate is usually included in Miracle-Gro. 

Potassium Sulfate in the Miracle-Gro potting Soil

Potassium is absolutely vital to plants, and it is actually considered a macronutrient (which means plants need this a bit more than other nutrients) for plants.

Potassium is found in Miracle-Gro because it regulates a plant’s cellular activity and reinforces the walls of the cells.

This essentially makes them more resistant to disease or damage. Potassium Sulfate doesn’t become part of the plant’s cells, but it works to move through them and helps to regulate nutrient intake.

Ammonium Phosphate in the Miracle-Gro potting Soil

Another essential addition to most Miracle-Gro products is Ammonium Phosphate. This is because plants rely on phosphorus for cell division purposes, and it helps them process carbohydrates for proper nutrition.

Root growth is also impacted by phosphorus supplies, as is seed development, but it’s worth noting that too much phosphorus can make a plant more at risk of certain diseases.

Are any of these ingredients from the Miracle-Gro potting mix likely to go bad?

Overall, the ingredients in Miracle-Gro have been specifically formulated to have the most extended life possible. Most of the elements are naturally occurring and chosen because they resemble a perfect growing condition for plants.

Miracle-Gro Peat Free Use and Storage

Miracle-gro also has a full range of peat-free composts which will also follow the guidelines within this article. The video below shows where I planted out a load of containers and baskets ready for a well-being garden I was creating using the miracle-gro peat-free composts.

Reduce Stress, Worry And Anxiety. Get Into Your Garden & Heal.

Storage considerations for Miracle-Gro

However, even though many Miracle-Gro potting mixes don’t have expiry dates, they will lose their effectiveness if not kept in the proper conditions.

A sealed fertilizer bag will last for much longer, and the fertilizer’s nutrients are less likely to have escaped gradually.

Providing the Miracle-Gro has been kept in excellent, dry conditions, hasn’t been left unsealed for a long time, and doesn’t look or smell like something is amiss – there’s no reason for it to go wrong.

Tips for storing Miracle-Gro and to lessen the chances of them going bad

Here are some things you can do to prevent your Miracle-Gro from going bad:

Store in a cool, dry placeAvoid constantly moving the bag
Ensure the bag is completely sealedAvoid exposing the bag and contents to direct sunlight
Purchase from a trusted retailer

Providing these measures are taken, there’s no reason that Miracle-Gro can’t last for several years. Even if the product loses its potency or fertilizing capability, it is unlikely that it will become harmful to plants or soil as a result.

At the worst, the fertilizer may become redundant or less fit for purpose as time passes. If the Miracle-Gro were to go “bad,” there would likely be warning signs regarding scent and appearance.


Conclusion on does Miracle-Gro go bad?

To sum it all up, if a bag of Miracle-Gro is unopened and kept in cool, dry storage space, the mix can last upwards of five years. The soil portion of the blend can stay indefinitely in the right conditions, but the added fertilizer will expire, rendering the Miracle-Gro useless.

To prevent the miracle products from going to waste, proper storage must be done to keep them at their optimal state for the plants. In line with that, it is recommended to use them all up within 1 to 2 years of buying.

If you liked this article, be sure to subscribe in the form below to be notified about future content and releases!