How long does a mushroom grow kit really last? An honest answer.
The honest answer is: it depends on what you mean by "last." And that's not a dodge, there are three different time horizons that all matter, and most companies only quote you the first one because it's the most flattering.
Horizon 1: Shelf life before you open the bag
A sealed ShroomBag stays viable for about 6 weeks from the day it ships. After that, the mycelium starts to consume its own resources without producing fruit, and pinning gets less reliable. We date every bag and recommend starting it within 4 weeks for best results.
If life happens and your bag sits for 8 weeks, try it anyway. Worst case you get a smaller first flush.
Horizon 2: Indoor productive life
From the day you cut the bag open:
- First flush: 10 to 14 days to harvest. Yields 0.5 to 1.0 lb depending on strain and conditions.
- Second flush: 7 to 14 days after the first harvest. Yields roughly 40 to 60% of the first.
- Third flush (sometimes): Lion's Mane occasionally produces a small third indoor flush. Oysters rarely do.
Total indoor productive life: roughly 30 to 45 days, 1.0 to 2.0 lbs of mushrooms.
After that the block gets light, the surface dries out, and no amount of misting will restart it. The block isn't dead, it's done indoors.
Horizon 3: Outdoor life (the part nobody talks about)
This is where the honesty really matters. A "spent" indoor block, when planted outdoors in damp shade with wood chips, can fruit for months or years. We have customer reports of ShroomBag plants producing across two seasons. We've seen our own test plants come back a third year.
Why don't most kit companies mention this? Because if a kit becomes part of your yard, you don't need to buy another one. Our business model is: we'd rather you tell ten people about the bag in your garden than buy a second bag to throw away.
Full instructions for outdoor expansion are in [Your ShroomBag isn't done].
What kills a bag early
For completeness, here are the things that genuinely cut a kit's life short:
- Direct sunlight, bleaches the mycelium and dries the block.
- Heater or AC vent airflow, desiccates the fruiting surface faster than misting can keep up.
- Letting it dry out fully, once the block is bone dry, it's hard to recover. Mist before you see cracking.
- Mold contamination, green or black fuzz means the bag was punctured or stored too long. Email us a photo and we'll replace it.
Bottom line
If you're comparing kits on the shelf and a competitor claims "12 weeks of mushrooms," they're either talking about a much bigger block or padding the number. A standard 5lb gourmet kit gives you about 30 to 45 productive days indoors. After that, the real second life starts, and that's the part we care about.
Bag arrived weeks ago and you haven't started? Cut it tonight. The mycelium would rather fruit late than not at all.