I have been using it for years with excellent results.
Have it in 6, 15 gallon pots with Tomatoes and one Bell Pepper and also in a large Vegtrug with 380 quarts of straight MGMC and nothing else.
In the tomato pots I have it mixed with a bit of Moo-Nure cow manure and compost mix.
You have to really soak the mix very well initially and have very good drainage.
All my tomatoes were transplanted into it.
Other than that there is no "Warning" to be had.

Works excellent.

Josh

So obviously cant be all that bad.

Here is my Tomatoes growing in this terrible stuff.

This Bush Tomato was 3" tall on April 28th, its over 4 feet tall now and its not even supposed to be 4' tall max height.

Green as can be, healthy as an Ox, loaded with tomatoes.

Bell Pepper growing is MGMC, over 4 feel tall, have already harvested 8 nice pepper from it in the past 2 weeks, there are 6 I am going to harvest today for dinner and there are at least 25-30 more on it.

Here is my Vegtrug filled with 380 Quarts of MGMC not mixed with anything else.
Its like a freaking jungle, the Bok Choy and Basil and Rosemary, Lemon Thyme, Cilantro, Lettuce growing so fast I cant even eat it fast enough, I had to prune the Basil just this morning and put 2 large branches in a jar with water in the kitchen. Will be pulling 2 Bok Choy for dinner also.
Have already pulled 7 Bok Choy and 3 Lettuce in the past 2-3 weeks and pruning the Rosemary wildly, I used several large branches last weekend just to throw on the smoker for smoke flavor.

So clearly what ever problems you may have has zero to do with the potting mix itself.
. .
.

Everything we have is growing in MGMC, every flower, every vegetable, a small sweet bay tree, and all doing very well.

I always use large containers minimum of 10 gallons, though usually 15+ gallons which I think is key for tomatoes and peppers.

The Vegtrug was an experiment this year, 1st year.
Next year I am going to stagger planting.
Plant a row of Lettuce then a row of Bok Choy wait 2+ weeks then plant another row of each and so on.
The herbs should still be there except for the Cilantro I will leave a little corner for that.
Everything is growing so fast that I cant eat it quick enough.

One nice thing about the Vegtrug though is the bug net, all my Lettuce etc is all bug free without any need for pesticides of any kind.
Also has a green house cover for winter so I grow Lettuce probably all year long.

But this is what the company says it contains.

++++++++++++++++
"Our potting soils generally contain peat moss (the major component that is harvested from natural peat bogs), compost (the compost may contain animal manures, composted leaves, grass clippings, and/or composted bark), and perlite (white volcanic rocks used for drainage and soil texture). Osmocote fertilizer that look like small clear fluid-filled balls.

The Miracle-Gro Moisture Control Potting Mix also contains composted hulls of coconuts to help absorb more water than regular potting soil. This is the Aqua Coir (pronounced "core") component of the soil.""
+++++++++++++++++++++++++++

It always looks good and looks the same to me and I bought 15, 55 Quart bags and 1, 64 Quart bag of it this year.

Much more than I have ever bought in the past because of the Vegtrug which took 7 full bags of it.

I also bought 2 bags of Moo-Nure to mix in the MGMC in the pots for the Dwarf tomatoes.
Everything else is straight MGMC.
Although I think in the future I am going to amend it with the Moo-Nure a bit for everything just to give it that extra nutrient content.

If I wanted to kill a plant, I'd put it in peat. But I wanted to stop doing that, so I stopped doing that. Wasn't working for me.

Hats off & cheers to those who have good results using these things, good job.

"Everything is growing so fast that I cant eat it quick enough."

"Everything we have is growing in MGMC, every flower, every vegetable, a small sweet bay tree, and all doing very well."

If not, you should.

Ron

There aren't any of those in it, it uses "Composted Coconut Husk" to hold water, although it doesn't seem to work all that well for that because I water heavily every single day unless it just rained pretty hard. Water drains right out of it very well.

""Are you in the Marketing Department for MG""

Nope, just a retired Marine Biologist stating a fact is all.
I buy the MGMC mainly because I can buy it at Costco and it is the cheapest good mix I can buy.
It cost $9.99 for 55 quarts.
If I could buy something else just as good cheaper I would in a heartbeat.

But when I see people slamming something that I am using and having absolutely NONE of the problems listed I feel I should chime in and say so.
There is certainly no reason for any "Warning".

I can see amending it a bit to match whatever the needs are of the particular plant you are putting in it, to match the Ph or nutrient requirements, but to say it will basically kill your plants is rubbish and simply not a factual statement. There is nothing wrong with at all.

Whether a grower can or can't grow well in any particular soil has no bearing on the evidence; that being that an extremely high % of growers arriving at this forum with plant health problems are using heavy soils, like Miracle-Gro and similar, and the problems are either directly related to water-retention and lack of aeration, or resultant of diminished vitality and impaired metabolism that results from that water retention. That too is a fact.

No one denies that you can grow healthy plants in Miracle-Gro soils and similar, only that it's more difficult and the margin for error significantly reduced. Heavy soils that support excessive amounts of perched water also limit the probability that plants could grow as close as possible to their genetic potential. Each time the lower reaches of the container becomes saturated, roots begin to die. The longer the duration of the saturation, the greater the volume of roots that die, and the larger the roots. When sufficient air returns to the soil between irrigations, roots can then begin to regenerate. This cyclic death and regeneration of roots steals valuable energy that might have gone to more flowers/fruit/bio-mass, so these heavy soils can be very expensive in terms of energy outlay.

I suspect that some of the problem the original poster had might have been related to using plants with a congested root system & not breaking up the roots. I literally rip the bottom half of the roots off, then tease the roots away from the sides of the root ball with a nylon tool I made.

The heat referred to is most likely not from an extraneous source, like passive solar gain. More likely it's a result of the ongoing composting process - like a hot compost pile. Using ingredients in a soil that break down quickly, especially if you add a measure of N, can easily raise soil temperatures 10-30* above what they would normally be, enough to have serious consequences.

Al

potting mix is pretty damn light, I can shove my hand right on down to the bottom of the pot with just a couple of twist.
When I run about 2 gallons of water on the top it drains right out the bottom like a kitchen sink, how much faster draining can it be than that?

Problems people have with light potting mixes like MG are because lack of drainage thus water retention.
Anything lighter than MG or what ever type of peat and compost potting mix you may as well go Hydroponic.

The original poster had problems due to not breaking up the root ball and not properly saturating the growing medium.

Just curious what would you consider lighter and faster draining and better aerated?
I will change to that magical substance next year, or at least amend what I already have with it.
I am not going to wing out about $160 worth of potting mix, but will certainly amend it as needed if something proves to be better.

The perched water table will be there with the smaller particles, which is why I only grow in very large pots of 15+ gallons with excellent drainage, thus the roots on my plants are larger before they even reach the last few inches of perched water than they would be in a smaller pot with large particles and perlite even if it has zero perched water. Plus I just plain prefer larger pots and bigger root systems no matter the medium.

I may buy a large bag or two of Pine Bark Fines and a bag of large Perlite next year to amend the mix I already have next year. I always lose some soil over the year after pulling dead plants etc, so will replace that with the pine Bark and Perlite just to get a bit better aeration.
But so far large pots with excellent drainage using potting mix and manure works just fine.

Unless one grows in very large containers (which are essentially mini raised beds),
container gardening is much closer to hydroponic gardening than in-ground gardening.

Josh

Anyway - I started a couple smaller pots with MGMC, and had some minor problems (which I now believe had more to do with what I was growing than the soil mix). Around April, I made my own 5:1:1 with composted pine bark and it worked fantastic.

This year, I couldn't find composted pine bark. But I noticed when emptying out last years MGMC pots into my raised beds, that it really hadn't collapsed / decomposed much. Even at the bottom of the pot, the mix was still surprisingly coarse.

So I bought some MGMC and sifted through it with my hands. In Texas at least, it appears the product is mostly composted pine bark. This makes sense, considering East Texas produces a huge amount of the stuff, and peat is considerably more expensive to ship in from Canada. Obviously it also includes pH adjustment (probably dolomitic lime, ash, or something like that), detergent treated composted coir, and some peat. So, I decided to try using MGMC as both the pine bark fines and peat component of 5:1:1. I guesstimate the measurements, and leaned heavily toward extra perlite (I have a lot of it). Nothing was screened or otherwise modified.

I used clear plastic cups to test for perched water. Nadda. Admittedly this is when the stuff is still new and fluffy, but I wasn't gentle with the watering at all.

Everything I've put in the mix has done great so far. It's a LOT, lot more expensive than last year, but I was getting desperate.

Just yesterday I finally found bark of the right consistency, though I'm not sure if it's already partially composted or not.. we'll see. $2.50 a bag. I'm going to use it to fill some very large planter boxes I made for containerized watermelon... 55 gallons. If I had to do that with MGMC, I'd probably cry.

Let me also add the caveat that it's very hot here. I have to water most all of my pots everyday, even though they're quite large. That's mostly because the plants in them are quite large, so they use up all the water everyday.

The inverted triangle cross section of the container is pretty much *ideal* as far as minimizing perched water. Even if the PWT was high, it would take up a much smaller volume of soil than in a regular container. I wonder if that was part of the design rationale?

The shape of the Vegtrug seems ideal with an amazing amount of soil right up to the edges. Even the very edge is 6 1/2 to 7" deep and drops off quickly so plants on the edge still have tons of root space.
Not only does the shape help the PWT but also the "Liner" you put in it wicks water out of the soil.

Only thing I would change about it is I would have made the covers taller, like at least 3 feet tall.

For what I grow in it, Lettuce, Herbs, Bok Choy etc it is perfect. I should be able to grow Lettuce all year now with the Greenhouse cover.

We get probably about the same Heat, Humidity and Disease pressure here in NC, plus we get the full 7 plagues of every kind of insect known to man.
That is why most everything I have is covered and next year will be better covered.
The Vegtrug obviously is best, but I am going to make my Tomato corner much more solid and covered next year.
I just have bird net over it which helps for birds of course but also at least helps keep the horn worm moths off of them.
Unfortunately I didn't make the netting tall enough this year, the plants grew taller than they were supposed to get so are growing up to and trying to grow through the netting which will give the moths a place to land on them.

I am going to go with white bug netting next year just like the Vegtrug over a solid frame of plastic coated steel poles with PVC connectors and pipe connecting the tops and making a frame work for the netting.
Depending on how well these Dwarf Tomatoes I just planted 7 days ago do I may grow nothing but Dwarfs next year which are only supposed to get a maximum of 3 feet tall but still produce full sized large Heirloom type tomatoes.
They should be easier to manage, produce nice fruit.

I also water my tomatoes and the bell pepper everyday as they drink so much in the heat and the pots drain very well.
The Vegtrug has such a huge amount of soil and everything is so thick in it its like a jungle so the soil stays moist for several days. I give them a quick spray on really hot days and a good drink maybe twice a week at most.

and today, 3 of those 7 days were were rainy and cloudy.

Large container users may benifit from having some 1/2 inch perforated pvc pipes sunk down into their containers (caps on the bottoms). Cut them off an inch or two above the soil level and put some unglued pipe caps on the top of them so that they can be uncapped and used to deep water specific areas from time to time without having to flood the surface too much. If the container should ever become totaly flooded from a storm, a smaller diameter hose can be lowered down into the pipes to siphon or pump out some of the excess water. Having the ability to bottom water specific areas may promote less congested root systems when the large planter contains a lot of plants. It may eliminate dry pockets or excessivly wet areas. I would probably drill the 1/2 inch pipe about every two inches with 1/8 inch hole on two sides.

This is what I plan to try doing with some 55 gallon plastic barrels I am going to plant potatoes in. I am currently using a mix very simular to miricle grow in 1/2 of a barrel, and will be adding more mix as the plants grow and using the perforated pipes to control the ammount of water delivered to the different levels rather than flooding the top to get water to the lower levels.

I plan to use whole barrels instead of half barrels next, and found this particular thread very helpful.