Miracle Gro Potting Soil Review & Tips

Sharing is caring!

For years, I’ve loved starting seeds indoors every spring to fill out a backyard garden. Recently and also in the past I have used Miracle-Gro® Potting Mixes potting soil to get our seeds started. I’ll give you my honest thoughts on this soil as a busy mama backyard gardener.

Over the years, I’ve noticed Miracle Gro is truly one of the biggest names in gardening. The Miracle Gro potting mix effectively helps my plants grow each year, whether starting seeds indoors in egg cartons, winter sowing in milk jugs, or filling some flower pots for indoor or outdoor plants.

Many gardeners gravitate right to Miracle Gro soil as a seed starting mix. At least that’s what’s happened to me. I found it prominently displayed and promoted in just about every garden section I found myself browsing.

Two bags of Miracle Gro Potting Soil Mix
Two bags of Miracle Gro Potting Soil Mix waiting for spring gardening!

What is Miracle Gro potting soil?

Miracle Gro soil is prepackaged potting soil that contains a mix of ingredients designed to help plants grow bigger, healthier, and stronger.

What’s in Miracle Gro potting mix?

The contents of Miracle Gro potting soils include sphagnum peat moss, perlite, plant food / fertilizer beads, aged bark bits, and a wetting agent, according to Miracle Gro itself. The Moisture Control® version of Miracle Gro also contains coconut coir (coconut husks) to balance moisture. This also helps you to avoid overwatering / underwatering your plants.

What are the little balls in Miracle Gro potting soil?

The little balls in Miracle Gro potting mix are Osmocote, a type of plant food. Sometimes green, yellow, or clear, the little beads in potting soil contain fluid that passes to the soil as needed to nourish the plants. Osmocote is generally recognized as a good all-purpose plant food / fertilizer.

Can you use Miracle Gro potting mix for indoor plants?

Yes, you can use Miracle Gro potting mix for both indoor and outdoor plants. The ingredients in Miracle Gro are suitable for flowers, fruits, vegetables, herbs, and various other kinds of plants.

What Is Great about This Mix

Miracle Gro potting mix is a trusty, time-honored seed starting mix to grow your favorite seeds into amazing flowers, vegetables, fruits, herbs, and beyond.

My favorite thing about Miracle Gro soils is that I *do* really feel like they give my seedlings a healthy start. The little plant food balls in Miracle Gro seem to jump start growing pretty readily in my experience.

Miracle Gro soil mixes moisten well and I’ve noticed seeds do germinate nicely in this soil, especially under lights.

I think the plant food may be a timed-release formula that seems to work well no matter what we grow. This helps back me up when I don’t always remember to fertilize seedlings after the first few weeks.

Miracle Gro Citrus Soil

I especially love the succulent, citrus, and cactus soil by Miracle Gro. It’s been great for my seed-grown lemon trees.

I also use this soil for succulents and succulent leaf propagation efforts.

Repotting a lemon tree with Miracle Gro, flower pots, small tree, and citrus soil
Here’s my effort to repot a lemon tree with the citrus soil by Miracle Gro.

What’s Not So Great

In all my years or using Miracle Gro mix to grow plants of all kinds, I really only have one main complaint.


That’s right, I am surprised my husband even lets me do indoor gardening anymore after our 2020 battle with fungus gnats that emerged from the Miracle Gro potting mix.

I am sure all potting mixes are capable of harboring pests like these. It just so happened that we got whacked with soil gnats twice when I was using Miracle Gro brand.

In researching this, I’ve found that some seasoned gardeners actually buy a dedicated microwave for heating up their soil. Others swear on pouring boiling water over it, steaming it, or otherwise sanitizing the soil from bacteria and insect eggs.

I have no doubt in my mind that microwaving dirt in my kitchen would not go over well with the rest of the family.

My 6-year-old may be fascinated and let me get away with it. Otherwise, I think I would risk losing indoor gardening privileges.

So, for the time being, we’ve taken a break from Miracle Gro mix for our annual seed starting efforts, for the most part. I use Pro Mix most of the time, instead, and so far so good on the fungus gnats.

That being said, I did still buy a few bags of Miracle Gro. I figured it would be nice to have on hand in case I run out of mix or for anything I want to grow in pots outdoors.

Package of Miracle-Gro Potting Mix

Final Thoughts on Miracle Gro Soil Mix

Right now, I am between using Miracle Gro potting mix and another awesome seed starting soil that I’ve found – Pro Mix potting soil. I love a lot of things about Pro Mix and wrote up my own review, but I’m not throwing the towel in on Miracle Gro soil yet either.

What I plan to do some of the time is mix 50/50 of Pro Mix and Miracle Gro potting soil. I’m planning to do that for some plants when potting up into bigger containers before hardening off.

For citrus and succulents, I will definitely be using Miracle Gro!

For seed starting, I think the Pro Mix is a good starting soil with less incidence of the gnats in my experience. That being said, I still love the healthy boost our young plants get from Miracle Gro.

Our website features affiliate links to products that we personally believe in. If you make a purchase from a link on our site, we may earn a small commission at no cost to you. Thank you! This helps our girls chase their garden dreams! Thanks for your support. (View full affiliate disclaimer at the end of the page.)

Miracle Gro Palm, Cactus, and Citrus Mix in Yellow and Orange Flower Pots
Miracle Gro Cactus, Palm, and Citrus Mix

What are your thoughts on Miracle Gro soils?

Do you use them for your indoor and outdoor gardening? Are there other points or experiences you’d like to share?

Definitely hit us up in the comments and we can dish on the dirt!

Happy Gardening!

10.03.22 – Updated to add helpful product suggestions. Improved spacing a bit.

Similar Posts


Leave a Reply

Your email address will not be published. Required fields are marked *