Miracle-Gro Potting Soil and Fungus Gnat Infestations

Suddenly have an insect infestation after using Miracle-Gro potting soils? Yeah, me too.

I was so ecstatic to have put together my first raised bed for a vegetable garden this year. It’s nearly full with mushroom compost received from a neighbor. The final touch was to add some garden soil to the bed and plant some seeds. A special at Home Depot meant that organic Miracle-Gro soil was just $5 a bag – a pretty good deal. I got two and immediately added it to my bed.

The next day, I went out to check on my raised bed and noticed the soil teeming with tiny little flies with white wings. These insects were NOT in the compost before I added I the soil, yet appeared in droves within 24 hours of dumping the bag of soil into my raised bed. I checked the mound of mushroom compost that I still had in another garden bed that was delivered the same day. Nope, the insects weren’t in there. I asked my neighbor if he had any problems with the tiny flies in his piles of compost. That was a negative, too. So I determined that the stupid organic soil that I bought from Miracle-Gro to complete my vegetable garden actually caused a HUGE problem that now I have to deal with.

Maybe it was the compost, or just a coincidence, you might say? Nope. I bought Miracle-Gro soil (the conventional kind) last year. I had three healthy houseplants that I had bought from the store and kept in pots for a few weeks that were fine. I decided to finally repot them and bought one bag of soil. All three plants were planted in this soil, and then placed indoors and outdoors in different locations. ALL the plants started developing problems and were infested with insects. I lost $30 of plants, tons of time in taking care of them, and time spent to return the stuff to Home Depot where the cashier looked at me dubiously as to how my soil could have caused this.

Now, fast forward another year, and I’m researching insect infestations online (I have so much time to do this, thanks Miracle-Gro!!) and finding out that this is a very common problem with Miracle-Gro, as evidenced in this stream of negative reviews on their website. In fact, most of the reviews are negative and have Miracle-Gro responding on how to get rid of fungus gnats because of their product.

I have been going to my new plant bed and soaking it with insecticidal soap, which apparently won’t work too well. Miracle-Gro suggests that I add sand to the top of my box. What?? How about I just avoid your product from now on?

Sure, there’s a money back guarantee on their bag. But how do I put soil back into a bag ripped in half to get the soil out? How do I return this nasty stuff to the store without getting it everywhere all over my car?!?  Most importantly, what about MY time???? The time spent in researching this problem, in tending to plants at risk, to monitoring insect populations and in applying remedies to problems that Miracle-Gro acknowledges? Isn’t my time more valuable than the $5 that I spent on their bag of soil??

Their response to past complaints is that it’s a natural product and not sterilized. True, I agree, however, this doesn’t seem to a problem with other soil that I have bought (just found Ecoscraps soil at Target after this fiasco and it looks good!). Why in the world would I willingly spend any more money to buy Miracle-Gro’s product and then spend hours dealing with the problems that their soil brings into my house and my life?

I am done with Miracle-Gro. I suggest you don’t try to pinch pennies like I was, buying the cheapest thing on sale, and go to your local garden center and get your potting soil and garden soil. It might cost more, but you will save so much time, money and energy in the long run – and actually might enjoy gardening, again.

Where do you get your soil? Have you ever had an insect infestation with any other brand?


  1. 1

    Pattee Shen says

    Hi–I have since set up a google alert with Miracle Gro, but I had the exact same encounter about two months ago with my houseplants. I had just bought the regular 1cu.ft of Potting Soil from Home Depot (fyi, the moment I grabbed the bag I KNEW I would regret it, but I was in a hurry and didn’t have time to hit my local garden center) I planted about 40 small seedlings of plants and the very next day…infestation started. I tried to fight it with the glue traps and even bought Gnatrol, but to no avail, I had to go through the tedious task of dumping back out all the old soil, rinsing off the roots, resit in water baths, to then wait 2 weeks for the nasty buggers to be gone out my apt. Over all, it took me about 2 months to bounce back. HORRIBLE experience. If you have the chance, go to Consumer Affairs and post a complaint. Finding others out there was a BIG HELP and have really confirmed my own suspicions that Miracle Gro is NOT the best product out there for gardeners, and IMHO now, probably the absolute worst. And also, very sorry to hear about your experience too. I hope you veggie bed bounces back too and you yield beautiful fruit without the help of Miracle Gro.

    • 2

      Kim says


      I appreciate you responding with your experience, too! It’s important to note it’s not the actual cost of the soil that’s the problem, it’s the time and energy and lost plants that are killed because of the soil. All gardeners know how much time and energy and love we put into our plants. To pay our good money for a corporation’s product which destroys all that, and then they just sit and say oh, well, it’s infuriating. We do have a choice and I know that your story will help shape other people’s choice, too! Thanks so much.

  2. 3


    Oh my Gosh Im here thinking it was the cheap stuff I bought,then to here your problem to. But I have to be honest I didnt have that problem till the cheap stuff. But also I never thought it could be the soil . Im off to the nursery for some better stuu than what Ive been using. Thanks girls

  3. 4

    Wes says

    Yup, same problem here. bought the 55 gal moisture control Miracle Gro bag at COSTCO. Repotted about a dozen inside plants. Now I have fungus gnats all over the place – on the windows, on the counter, flying around the breakfast table. Going to take the bag back to COSTCO and get a refund. Now I have to either repot the plants with a more reliable soil or get the little powder additive to add to the Miracle Gro soil to get rid of the gnats. What a pain.

    • 5

      Kimberly Button says

      Thanks for your story, Wes. Every single time someone else tells me the same story, I know it’s not just a one-time problem. It’s a real issue that needs to be addressed by Miracle-Gro. We gardeners are paying the price, though.

  4. 6


    Same issue here, thought it was bad luck with my choice of plants but realized it was the soil. Note I have amaryllis and rosemary that are infected with these little buggers. Insect soap failed for me as well. Next I tried vinegar and finally is seven if all else fails. I will not be buying miracle grow next year.

  5. 7

    Roz says

    I spent a lot of money on Miracle Gro soil. And now I am fighting bugs. I need a solution as to how to get rid of the bugs without losing my plants. I have two large bags.

  6. 8

    ERNIE BUSCH says


    • 9

      Kimberly Button says

      Thank you so much, Ernie, for sharing your story, too! With every story like this that is shared, it’s becoming apparent that there are tons of people having this problem, too.

  7. 10

    Billy says

    I was planning on giving gifts of plants I have grown! Used MIR GO SOIL NO GIFTS FOR NOBODY!!! Unless they are into flying bugs! Tried lots,, raw potatoe to capture larve,,vinegar to drown flyers,,now trying fly paper,,I may have to resort to sand,,I cant even type here in this forum what I would like to say to miracle grow!!

    • 11

      Kimberly Button says


      Thanks so much for sharing your story, too. I’m sorry that you’re having to go through that. Hopefully your gifts will turn out all right with your guiding care :)

  8. 12

    Patty McAlister says

    You can get rid of the gnats by using 3 % hydrogen peroxide WITH NO ADDITIVES. The formula is 1 part peroxide with 4 parts water. Water your plants as you would normally. I’ve tried it and it works, the larvae die on contact. It doesn’t kill the gnats but they will die off anyway. I watered with the mix till I saw no more flying around, dead in sills or on floors or in the pots. It is inexpensive and will not hurt your plants mixed correctly and it’s actually good for them. Beats having to re-pot and replace plants. Miracle Grow is horrible and didn’t use to be. I’ve had to do this a many times after re-potting with a number of potting soil brands even with soil at garden centers. Try it, you’ll like it. The solution will fizz up on the soil but that isn’t a problem. The larvae die on contact. Biggest thing is watering long enough with the solution to totally get rid of them. Don’t stop before the real miracle happens.

  9. 14


    No more miracle grow for me. Transplanted 3 banana trees using it and the bats are awful. Went to garden center bought Bonide granuals and plant spray to help kill the bugs. Did not have good results. Hate to get rid of plants but family ready to throw them out. They are all over again. I will never use miracle grow again.

  10. 15

    Ellie says

    I just bought Miracle Gro potting mix today from Canadian Tire to start some of my veggies indoors. Opened the bag and a little black fly flew out. Looked in the bag and there were dozens of them :( Needless to say I’m pretty ticked!

Got a great tip, story or idea related to this post? Let me know what you think!