How To Grow Tasty Mushrooms With Coffee Grounds And Cardboard

If mushrooms are a culinary delight in your kitchen, consider growing them on your porch with just a few simple supplies instead of spending money at the store. Mushrooms have a plethora of healthy benefits. According to Cedars-Sinai, mushrooms may help reduce your risk of cancer, they're good for your heart, support cognitive health, boost the immune system, and are beneficial for gut health. You can't go wrong with adding some mushrooms to your meals, and if they're ones you grew yourself, they're even more satisfying to enjoy. (It's also safer to grow your own than to accidentally eat a deadly mushroom growing in your yard.)

If you're ready to add more homegrown mushrooms to your diet, you'll need the following supplies to get started — freshly brewed coffee grounds, corrugated cardboard, a knife, water, a pot, a gallon-sized water bottle, a plastic bag big enough to cover the water bottle, mushroom spawn, and something to poke holes with. You'll be using the water bottle as your planter, so one of the bigger bottles will be the best bet, as you want to be sure there's plenty of room for the mushroom roots when they begin to grow. You'll also want to cut your cardboard into smaller squares so that it fits in a pot of water (we'll explain why in a moment). Try to find untreated cardboard so that your mushrooms will flourish.

Before starting the rest of the project, you'll want to soak your cardboard pieces in a pot of water for a couple of days. As for the coffee grounds, which you can use in all sorts of unexpected ways, you'll need some that have already been brewed but that are still fresh — don't let them dry out first because they can become contaminated. If you're not a big coffee drinker, you can ask a local coffee shop if you can buy a bag of freshly spent coffee grounds from them. 

Next, partially cut the top of your water bottle on three sides, creating a hinge that acts as a lid you can open and close. You'll also want to poke a few holes in the bottle to let air get in. The cardboard will help keep mold at bay while the coffee grounds will provide nutrients to help the mushrooms grow. People are adding cardboard to their raised garden beds, so why not use it in planters as well? 

Take your mushroom spawn, coffee grounds, and wet cardboard then layer them — one after another — until the bottle is filled. Then, bring your partially cut lid back down and place the bottle in your plastic bag. The bag will help keep humidity in the bottle, helping your coffee soil stay moist and motivating your mushrooms to grow. You'll want to keep your mushroom container in a darker and shadier part of your porch until the mushrooms start sprouting in a week or two. Once you have a little forest of sprouts started, you can move the container out into the sunshine. After another couple of weeks, your mushrooms will be ready to harvest and eat.