So I have this houseplant potting mix, moisture control Miracle Grow brand. I had it for a few months, used about half, left the other half in the bag, zipped locked. Went in the other day and it had grown mushrooms?? I tossed the remaining stuff, wasn't sure if it would be good to use anymore
I don't think the mushrooms would do any harm ... must have been spores that sprouted in the mix. I sometimes find mushrooms growing in my houseplants and I use the MG soil too. I just pull them up whenever I see them.
the spores were probably not from the mix, but after it was exposed to air and water. fungal spores are everywhere in the air. then they found a place that had good soil and moisture and grew.
Mushrooms they are, but will probably be the harmless type, Mushrooms can only grow on dead or decaying matter, so they would have already spored onto the stuff the compost was made from, they need dark, warm but dampish growing conditions to sprout, so you will be giving them all they need in a house plant or in a pot. best thing to do is, gently tease away the compost from the roots, wash the roots in water, replant into a new clean pot with fresh compost, you dont say what type of plant you are growing, but if it is a woody plant, the washing under running water should get rid of any stray spores attached to the roots, if left, I cant see them harming your plant in any way, there are some fungus (mushrooms) that will kill living plants, but these are not one of them, always wash your hands after touching mushrooms as some are poisonous to humans and if unsure of the type, dont take any chances. Good Luck. WeeNel.
I have never had mushrooms grow in my poting mix. Sometimes I get other fungi like mold but only in the moist unsterile poting soil. Some plants don't care if the soil is sterile but for the ones that do I never get the moist poting mix, I get the sterile dry kind. If I find mold in my poiting mix I don't throw it away it would propably be easier to do so and just get a new bag but I am too frugal. So I spead it out on a tray like jelly roll pans to let it dry. After it is dry I put it in the oven at 400 F untill the temperature of the soil reaches the same temperature as the oven. Doing so insures that the fugi and bacteria are dead making it sterile for use. I would suggest that you didn't use you best pans.
Mushrooms spores will grow on any woody decaying fibers and sometimes these are added to compost heaps to let air into the heap, the woody stems take much longer to die down, so when we buy or make compost, we often get bits of stuff not quite composted, it wont harm plants growing outside as it usually continues to rot naturally, but indoors, you give the mushroom spores the right conditions to grow, heat, darker and moist, that's all that has happened, usually bought compost for indoor plants has been sterilised either by going through a heat proses or the compost heap has been brought to a sufficient temp to kill of most bacterias and diseases, these mushrooms are neither of those things, but are the spores of a plant, fungus, mushroom which is different from mould, the spores get carried by wind also, so it could have got blown from anywhere, they dont harm the plants but will spread more spores as they start to decay after a while. good luck, Weenel.
Thanks everyone, yes I read also on line that the mix probably just wasn't baked enough in the sterilization process. I tossed it when I saw the mushrooms and mold. Now I know that it was probably harmless..oh well. In the future I will get smaller bags or perhaps use the whole bag quicker rather than have it sitting around in my warm apartment
It is a misconception that commercial and retail potting mixes are "sterile" literally. I can't think of a single soil manufacturer that uses steam heat for sterilization, although it is very effective. Most mixes are sterilized by the compost process, and afterward the soil can sit for a lengthy period before being shipped or bagged. The term "sterile" has its own definition within the media industry and applied mostly to diseases and weed seeds. Fungi is unfortuately common in a lot of mixes (higher organisms are not as susceptible to the conditions in composting as bacteria and the like) and I've even found bags with fungus gnat larvae in the soil. The mushrooms are not harmful to living plants, but they are unsightly, can be plentiful and can smell. The simplest way for a homeowner to manage them is to continually pull the mushrooms out removing as much of the underlying mycele every time they appear.
