I have a very large bag of Miracle Gro potting soil that's been sitting on
my porch all (Nebraska) winter.
Is it still OK to use? I have a few houseplants that need transplanting
into larger pots and wondered if it would be alright to use this potting
Thanks in advance.
depending on the servings, and amount left in the bag..........but seriously
for a moment........baking the soil for an hour at 275o will make SUCH a
stink.........and it's MIRACLE GRO soil, it has FERTILIZERS and TIME release
substances. She'll render those down to useless. Like Ann said, it's
probably frozen, so bring it into the garage or kitchen or utility room to
thaw,wherever you're going to pot these plants up at, and check for bugs,
and pot those houseplants up with no problem. The shock of fresh soil will
make them nuts and since it's Miracle Gro soil, the time release nutrients
will start them in an early spurt of growth. Me? I'd top dress the plants
at the end of February or mid March.
I understand the need or desire to pot up houseplants right now though. It's
the only way with winter going on outside to get our hands into the soils
until true spring. I do it myself all the time. But please, I suggest you
DON'T bake that soil. If it were just plain stuff, maybe. But it's been
altered and you risk causing the ingredients they put into the soil to be
destroyed and defeating the purpose of it being "Miracle Gro "soil". Not to
mention the stink that will be caused once the stuff heats up............
madgardener who sterilized soil in a microwave once and it took several
sticks of incense, some Lysol room deodorizer and open doors in the middle
of a wintery blast to rid the house of the smell, and it still had a
lingering odor for weeks afterwards (not to mention I had to clean the
microwave with bleach twice before ridding the thing odor free. Can you
imagine what the first batch of popcorn smelled like when I discovered after
cleaning the oven once that it wasn't quite nuked stinky soil free smell
yet? euwwwww live and learn)
I've had no problems baking soil. It does cause an odor, but it is
not objectionable and it dissipates quickly all on its own. It does
not linger and has a slightly caramel-earthy odor. Baking does
destroy the bacteria, but there's plenty microbes around to inoculate
the soil immediately after cooling.
Yours doesn't smell? I was lucky. The first time I baked dirt I did it in my
grill. I learnt early to NOT try this at home....or at least IN the home :>)
Definately up there on the list of worst smells ever.
I regularly purchase potting mix in the 2 cubic foot bags, and almost
always more than I need for the current job at hand. Opened bags are
dumped into a large trash barrel with a tight fitting lid and kept in a
"bin" on my "potting bench". This is outside as I find it a much
better place for such things. Unopened bags are stacked nearby.
Freezing and thawing over the (long) winter takes care of any bugs and
most other fungi problems. However, there are beneficial fungi that
are found in certain types of soil and soil less mixes so I do not
worry too much if any do show up. I do not bake or by other means
sterilize the potting mix I use. and have not ever had any problems.
I use the same potting mix for all of my planting needs, from sowing
seeds to transplanting to potting up blooming sized perennials, as
well as all of my various types of house plants. The only thing I have
even added has been perlite to increase the drainage and aeration for
I've not had potting mix get "stale" per say, but I have had it get a
bit too dried out. In which case I mix it 50/50 with a new bag. If I
do not need to use it immediately, I will give the newly mixed media a
good watering, a quick "stir" with the spading fork and then leave it
alone for a few days with the lid off (unless there's rain in the
If by some remote chance your bag of potting mix has gotten too wet and
has soured, it can still be salvaged by opening the bag and dumping the
contents onto the ground (preferably a paved surface) letting it dry
out and then mixing in new potting mix. Cover this with a tarp and let
it "cook" for a couple of weeks and it should be ready to use - in the
garden or for potting up planters and barrels that will be used
outside. I would also NOT USE that particular brand again.
Potting soil rarely stays in a bag long enough here for it to "go
One winter -- no problem.
Five winters -- the bag will probably disintegrate from being in
sunlight too long when you try to move it.
Either way, if the bag is intact you can probably still use it. Just
check for things growing in it before using it for something you will
depend on. If there's moisture in the mix (there's generally some when
you buy it) you could get moss growing in it. That's fairly easy to
remove because it makes fairly cohesive lumps.
Try one (minor) houseplant and see if it has any problems. If no
problems arise after a couple of weeks, do the rest of them.
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