Miracle Gro Potting Soil Review for Microgreens

Is Miracle Gro potting soil a good choice for growing microgreens? In this Miracle Gro potting soil review, we test how well microgreen varieties that are harvestable in as few as seven days and those that can take up to a month before they are ready for harvest.

The Miracle Gro potting soil review also include articles on the ingredients in the potting mix and describe and explain each ingredient, how it is formed or sourced, and if they harm you or the environment.

the ingredients in miracle gro potting mix

Miracle Gro Potting Soil or Miracle Gro Potting Mix?

Actually, the product is called Miracle-Gro Potting Mix. Most (maybe all) indoor growing media are mixes. If you’re unsure what the difference is between “soil” and a “mix,” I have an article explaining what soil needs to contain to be called soil.

However, I frequently call potting mixes potting soil as it has been driving into my brain after years of selling it in my teens and twenties. So, if you read soil, think mix.

Please don’t call it dirt.

Soil or potting mixes are what we grow plants in. Dirt is what you sweep off the floor.

Here is How Well Miracle Gro Potting Soil or Mix Grows Microgreens

In the video below, Miracle Gro Potting Mix is tested with Home Microgreens Potting Mix to see how well it grows Purple Vienna Kohlrabi and Genovese Basil microgreens.

home microgreens sells seeds

FREE Home Microgreens Grow course that teaches you the basics of growing microgreens in your home! There are 12 video lessons (over 120 minutes), downloads, and more written information and tips!

Home Microgreens potting mix is used as a standard because I’ve trialed many different potting mixes against it, and it does a great job.

More Video to Come Using Miracle-Gro Potting Soil

Because the video would be too long if I included the basil footage, part two of this article will be dedicated to how well Miracle-Gro potting soil grows longer growing microgreens.

Links to part two of this Miracle Gro Potting Soil review and other articles and such mentioned in the video are provided in the write-up below.

Miracle Gro Potting Soil Review

Here are my thoughts and recommendations for using Miracle Gro Potting Soil for microgreens and other indoor garden plants.

This article will be focused on what ingredients are in the potting mix, how easy it is to use, and how well it performed when growing quick-growing microgreens like Kohlrabi, broccoli, kale, or other microgreens that are ready to harvest in ten days or less.

First Sticking Point to Overcome

Before you go out and buy Miracle Gro Potting Mix you should come to terms that it contains synthetic fertilizers.

I know this is a no-go for many of you. But hear me out.

There may come a time when you need a potting mix, and Miracle Gro is a popular brand available almost anywhere. Don’t forget that a chemical in itself is not harmful; only the dosage of that chemical can harm you.

*Spoiler Alert: I always keep that in mind. I will not use Miracle Gro Potting Mix to grow my microgreens unless it is all I have available. It is the best of the worst choices, or finances determine my buying decisions, mainly because of the synthetic chemicals on principle and not for health reasons.

But that is a choice you must consider before even buying this Miracle Gro product.

Is Miracle Gro Potting Soil Safe to Grow Vegetables?

According to Scott’s product website, Miracle Gro Potting Mix is safe to grow vegetables and greens. I have no proof other than what they state on the website, nor could I find any agency or watchdog group that says otherwise.

Here is a statement on the Scott’s website (taken in 2023)

miracle gro potting mix is safe for use on vegetables

Reasons 1 & 2 for Using Miracle Gro

This potting Mix is by far the most common potting mix found on the shelves of mass market retailers.

It can be found everywhere. Most of the larger stores carry 8-quart and 2-cubic-foot bags. Amazon does have a 1-cubic-foot bag that is a nice middle size.

The second reason is that it is inexpensive. Saving money is always good.

What Ingredients Are in Miracle Grow Potting Soil?

The potting mix ingredient list differs depending on what state (most likely country, too) it is sold in.

The short of it is that the ingredient list contains peat, sphagnum peat, forest products, maybe coco coir, perlite, synthetic fertilizers, and synthetic wetting agents.

I have an article that explains all of the ingredients in Miracle Gro Potting Mix and also explains what wetting agents are and what chemicals are in them.

How Easy is it to Use Miracle Gro Potting Soil?

As a side note, Home Microgreens Potting Mix contains only natural amendments. There are no synthetic products; instead of a peat base, it is mostly coconut coir-based. I also have an article on what ingredients Home Microgreens Potting Mix contains.

I found that Miracle Gro potting soil is easy to use. It is fine enough for easy spreading and leveling in the trays.

There is a bit of inconsistency in the size of the forest products, but not to a point where it is difficult to use.

I did find that Scott’s potting mix didn’t wet as well as the Home Microgreens Potting Mix. You can see that in the video.

Home Microgreens Potting Mix on the left & Miracle Gro Potting Mix on the right.

However, it wasn’t so slow that it inferred with sowing seeds like some mixes have in other trials. It makes me wonder if it will absorb or wick up water and a coir-based product when bottomed watered.

Overall, I found it easy to use Miracle Gro Potting Soil when filling trays or sowing microgreens.

How Well Does Miracle Gro Potting Soil Grow Microgreens?

The video shows that the potting mix grows microgreens (at least quick-growing ones) very well.

Miracle Gro Potting Soil grew the Purple Vienna Kohlrabi as well as the Home Microgreens Potting Mix. If not a little larger.

miracle gro potting soil growing kohlrabi
Home Microgreens Potting Mix on the left and Miracle Gro Potting Mix on the right. Both trays of Purple Vienna Kohlrabi look great.

To see how well Miracle-Gro Potting Mix grows slower-growing microgreens, we ran the same trial using Genovese Basil.

The only difference between the Miracle Gro mix and the Home Microgreens mix is the amount of watering. It appeared that the Scott’s product required more water than the Home Microgreens Mix.

Both trays were given the same volume of watering.

I don’t think that the growth rate between the two would cause the difference. It might have to do with the way a peat-rich mix loses water to the atmosphere compared to the coir-based HM potting mix.

It could also be the difference in the overall grain size with more air space in the coarser peat-based mix.

Overall, the watering aspect is not a big deal or game changer.

Something to Think About

Synthetic fertilizers are touted to grow plants quicker than those grown in soils with natural amendments. But if you look at the results below, you will see that there isn’t that much of a difference between the two trays.

Again, HM potting soil has only natural amendments, while the Miracle Gro has more soluble synthetic fertilizers.

Miracle gro potting soil grow trial verse Home Microgreens potting mix growing kohlrabi
HM Potting Mix on the left and Miracle Gro Potting Soil on the right. The Purple Vienna Kohlrabi grown in the Miracle Gro is a bit taller.

There may be more of a difference in the basil microgreens in part two of this article.

Do I Recommend Miracle Gro Potting Soil for Growing Microgreens?

If you can warp your head around the synthetic fertilizer and wetting agent, Miracle Gro Potting Soil will grow microgreens very well.

It is easy to find, relatively inexpensive compared to other potting mixes, easy to work with, and it grows colorful microgreens quickly.

As mentioned, I’m not a fan of buying short-term products that contain petrol-based ingredients. I’m still unsure about the health concerns of the ingredients in wetting agents. But I will say that this product does not contain a significant enough volume of wetting agent to make much of a problem.

Besides the synthetic chemicals (I try not to use any in my food product), my principal reason for not supporting Miracle Gro is the Scott’s brand itself.

I’m not fond of the conglomerate companies that buy up or take over brands. I’m not getting into all the reasons here; I’ll only state that I like to support small companies that are not part of larger entities.

But I’m not here to judge anyone’s decision (nor should you), and if someone is comfortable with a product, what it contains, and who it supports, then by all means, Miracle Gro Potting Soil will grow outstanding microgreens for you.

If You’d Like to Support a Small Family Business

Check out the Home Microgreens store.


  • Todd

    Todd is the founder of Home Microgreens & the Home Microgreens store. He also writes for several other websites, including MyViewFromTheWoods.com. Todd worked at a large farm market, garden & nursery center for 20 years. Somehow he snuck off to become a geologist and professor before coming back to his senses to write & lecture about microgreens and gardening. When not at the computer, he can be found in the garden, trout stream, or mountain trail with his new Springer Spaniel Caden.

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