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oyster grow kit instructions

Oyster Grow Kit Instructions

Questions before you start? Read below and visit our FAQ page.

How to Start

  1. 1 Do not remove the bag. The block will dry out and you'll get a reduced yield.
  2. 2 Slice a 6" gash on the side of the bag, then face the gashed side up. Wrap the excess plastic tightly around the top of the block and tuck it under.
  3. 3 Place the block back in the box and leave it open. The box keeps the plastic snug against the block and eliminates excess air around it.
  4. 4 Spritz with water 3–7 times a day. Oyster mushrooms like a lot of moisture — keep the surface visibly damp.
  5. 5 Find a spot with indirect light and no direct sunlight. A kitchen counter or bathroom offers the right amount. Avoid heating vents and stagnant corners — mushrooms need fresh air.
Pins will appear in 2–5 days and double in size daily. You'll see visible growth between your morning and evening mistings.

How to Harvest

Mushrooms are ready in approximately 7–10 days. Harvest when the edges begin to uncurl and caps lighten in color — don't wait for caps to flatten completely or they'll release spores and lose texture.

  • Grab the entire cluster at the base and twist gently to pull it off.
  • Don't harvest individual caps — take the whole cluster at once.
  • When in doubt, harvest a little early rather than late.
  • Two harvest photos below - note that final color and texture will depend on growing conditions. 

Extra Flushes

  • Let the block rest for 1–3 weeks after harvest. Don't unwrap or disturb it during this time.
  • Soak in water for 12–24 hours (keep the block in its bag), then repeat the process.
  • New growth typically appears around the edges of the old growth site.
  • Expect 2–3 flushes total. First flush yields approximately 1–1.5 lbs; subsequent flushes will be smaller.

Storage & Preparation

  • Store in a paper bag in the fridge so they can breathe.
  • Never store in plastic, glass, or ceramic — mushrooms need airflow or they'll go slimy.
  • If mushrooms start to dry and shrivel, that's fine. Chop and cook them and they'll rehydrate beautifully.
  • Visit our recipe blog for serving ideas.

After You're Done

Worms love spent blocks. Toss yours in the compost pile or tuck it under a shaded garden bed — you might get a bonus flush after a few days of spring rain.