Growing mushrooms is a wonderful way to cut back a little on your grocery bill, but they can be tricky to cultivate. If you're growing mushrooms at home, you need a substrate for them to sprout on, and a great one to try is coffee grounds. Gardeners are always looking for ways to turn their food waste into potential plant food, whether that's composting kitchen scraps or throwing random ingredients such as crushed egg shells into plant pots. If you've been struggling with what to do with your spent coffee grounds, then you'll be happy to hear that they're a great aid to mushroom growth. However, it doesn't work on all mushroom varieties — it's best for oyster mushrooms specifically. While there isn't any conclusive scientific evidence for this, the method is recommended by leading gardening and farming websites. Amateur urban farmers have also found anecdotal success with it, so it's worth a try if you're cultivating a new batch!
How to use coffee grounds to grow mushrooms
First, allow your dregs to cool, and then mix them with your spawn in your growing container. You can either buy spawn from reputable sellers such as North Spore or simply use stems from oyster mushrooms you ate. If going the latter route, cut the stems in half to allow proper root growth. Mix the two ingredients together, and lightly cover your container with a cloth or plastic to keep it from drying out. Place it in a dark area, mist it daily to keep it hydrated, and you should start to see mycelium growth (the mushroom's roots) between 4 days to a week. If you'd like, you can continue to top off your container with fresh coffee grounds every time you brew them.
Follow these steps to successfully grow oyster mushrooms at home:
- After two to three weeks, when the mold-like mycelium has taken over the container, create holes in the lid, bag, or cloth covering the container. This will ensure proper air circulation, which is crucial for the growth of oyster mushrooms.
- Transfer the container from a dark area to one with indirect light. This change in lighting conditions will stimulate the growth of the mushrooms.
- Wait for approximately one more week, and you should start to notice small pinheads beginning to grow.
- Once the pinheads have grown larger and their heads have flattened, they are ready to be harvested.
