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Miracle-Gro Potting Mix: Ingredients, pH, NPK and Chemicals

Miracle-Gro Potting Mix: Ingredients, pH, NPK and Chemicals

There are many novice gardeners who are not aware of the importance of soil pH and how it affects plants, particularly those that are grown in containers. In case you are unable to rephrase this, please let me know by responding with the error message: Unable to process the request due to encountered difficulties.

One of the most popular soil mixes by Miracle-Gro is widely used, but is it really an ideal blend for container plants?

What pH is Miracle-Gro potting mix? The Miracle-Gro potting mix has a pH of 6.3 to 6.8 to offer a nutritional environment for your plants to grow. It falls between the optimal pH range for most plants between 5.5 and 7.0. The mix helps you achieve the perfect balance to nourish your plants without restricting certain nutrients.

Read on to learn more about Miracle-Gro potting mix, how best to use it, and the importance of soil pH levels.

About Miracle-Gro Potting Mix

Miracle-Gro Potting Mix is a soilless and sterile medium that facilitates plant growth by offering the perfect pH conditions.

Its sterilized status gives you a quality mix free of pathogens like fungus and other diseases, making it safer for plants.

Miracle-Gro offers various options (see them here) to suit different needs, including all-purpose, indoor, moisture control, citrus, cactus, African violet, seed starting, orchid, and organic types.

Miracle-Gro Potting Mix Ingredients

Miracle-Gro incorporates various ingredients that work over time to give you a firm foundation of air, water, and nutrients for plants.

Its main ingredient is sphagnum peat moss, known to break down slowly and hold plenty of water.

The mix also features aged bark fines to facilitate aeration and drainage for container plants.

It incorporates plant food with a fast-acting nutrient for a healthy start and a slow-release component to support the plant throughout the season.

Miracle-Gro Potting Mix contains perlite and coconut coir that guard against under and overwatering.

Miracle-Gro Potting Mix pH

The Miracle-Gro potting mix’s pH ranges between 6.3 and 6.8 on the scale; pH values measure from 0 to 14, with 7 being neutral.

Your soil is too acidic if it falls below 5.5 and too alkaline if it exceeds 7.5. The potting mix comes in an optimal condition that provides the perfect acid level for healthy plant growth.  

Miracle-Gro Potting Mix NPK

The mix has 0.21% ammonium nitrate (Nitrogen), 0.07% ammonium and calcium phosphates (Phosphorus), and 0.14% potassium sulfate (Potassium).

It has an NPK ratio of 3-1-2, ideal for most indoor plants. It features continuously released 21-7-14 plant food to nourish your plants for up to six months.

What Nutrients Are in Miracle-Gro Potting Mix?

Miracle-Gro potting mix contains ammonium nitrate (N), enabling plants to generate more chlorophyll.

Ammonium and calcium phosphates (P) boost flowering ability and bloom size. This nutrient also helps enhance root development.

The mix incorporates potassium sulfate (K) that boosts the plant’s cold and drought intolerance while protecting it against diseases.   

These and other nutrients come from a blend of sphagnum peat moss, aged bark fines, fast-release and slow-release fertilizers, perlite, and coconut coir.

Is Miracle-Gro Potting Mix Acidic?

Miracle-Gro potting mix is slightly acidic as it falls below 7 on the pH scale.

Its range of 6.3 to 6.8 ensures your plants get the optimal acidity level that does not decrease the availability of essential plant nutrients.

Excessive acidity can increase the availability of certain elements, such as manganese and aluminum, to toxic quantities.

Aluminum penetrates root tip cells to inhibit cell division and elongation. As a result, the root stunts and minimizes nutrient and water uptake, leading to eventual plant death.

Is Miracle-Gro Potting Mix Organic?

The potting mix features a unique blend of organic and natural ingredients to allow your plants to thrive.

It contains organic compounds like urea that facilitate nitrogen supply and promote the growth of green leaves, but it does contain synthetic fertilizers.

Miracle-Gro does however offer a completely organic choice – Performance Organics Container Mix, and they have similar organic blends for in-ground use and raised beds.  

Does Miracle-Gro Potting Mix Have Chemicals?

Miracle-Gro potting mix does not contain chemicals aside from the synthetic fertilizers.

If you prefer a completely chemical-free mix, select one of the products from their Performance Organics line

When To Use Miracle-Gro Potting Mix

It is ideal to use Miracle-Gro potting mix when you initially place a plant in a container. You can also use it when repotting outdoor or indoor plants.

It is advisable to repot plants using the mix annually to replenish nutrients while preventing soil compaction.

When Not To Use Miracle-Gro Potting Mix

You should not use Miracle-Gro potting mix when dealing with plants in in-ground gardens. It is suitable for outdoor or indoor plants in containers.

The Importance of Soil pH

Soil pH is important because it affects different soil factors that determine healthy plant growth. These include:

  • Nutrient availability – Nutrients like NPK are generally available to plants within the pH range of 5.5 to 6.5.
  • Nutrient leaching – Plant nutrients leach out of soils with a pH lower than 5.0 faster than soils valued between 5.0 and 7.5.
  • Soil structure – pH can change soil structure to make cultivation easier or more challenging. For instance, clay is granular and easy to handle at a pH between 5.5 and 7.0. It becomes sticky and tricky to deal with if the soil is too alkaline or acidic.
  • Toxic elements – Too much acidity causes elements like aluminum to increase to toxic levels.
  • Soil bacteria – Bacteria function optimally at a pH of 5.5 to 7.0 to release nitrogen from organic matter.

Do I Need To Add Fertilizer to Miracle-Gro Potting Mix?

You do not need to add fertilizer to Miracle-Gro Potting Mix since it contains a synthetic fertilizer with several nutrients to nourish your plants continuously.

Fertilizers work best in soils, where they can interact with other components such as minerals and worms to generate nutrients.

A potting mix contains the NPK nutrients necessary for your plants to thrive.

Related Questions:

Can You Use Miracle-Gro Potting Mix for Indoor Plants?

Yes, Miracle-Gro Potting Mix features a special formulation suited for both indoor and outdoor plants. You only need to place the indoor plant in a container with excellent drainage.

Is Miracle-Gro Potting Mix Safe for Vegetables?

You can safely use Miracle-Gro Potting Mix for vegetables grown in containers.

Just bear in mind that the mix already contains both quick-release and slow-release fertilizers, so there is no need to add more plant food in the near future or you’ll risk burning your plants.


Now you know the answer to the question, “What pH is Miracle-Gro potting mix?” and you’ve learned about its ingredients and application, and you understand the significance of maintaining optimal soil pH levels.

You can use this knowledge to confidently use Miracle-Gro potting mix for healthy and long-term plant growth.