Does potting mix really go bad or is it a marketing thing?

After my cherry tomatoes died two weeks after repotting in a bag that sat on my balcony all winter, I'm wondering if old soil is the real killer or if people just blame it to sell new bags - what's your experience with using leftover mix from last season?

2 comments

2 Comments

robinson.quinn1d ago

Bag of soil that sat through a Minnesota winter killed my basil too. It's definitely real, old soil gets all compacted and nasty and probably grows mold spores.

nelson.gavin1d ago

@robinson.quinn nailed it with the mold and compaction thing. My old mix from last season turned into a brick and grew white fuzz on top after sitting through a rainy spring. Last year's bag might still work if you fluff it up and mix in some fresh stuff, but straight out of an old bag is risky. Your mileage may vary though, some folks get away with it if the bag stayed dry all winter.