How to Grow Magnificent Mushrooms at Home

Growing mushrooms is a blast for a fun guy like me! What do you mean, that old chestnut? When it comes to mushroom puns, the world’s your oyster. Mushrooms are great for breakfast – in fact, they’re the breakfast of champignons. They really are the good shiitake! (Sorry, that one was in spore taste.) They’re all delicious, that’s the morel of the story!

Dad jokes aside, mushrooms are a great way to get the little ones involved and interested because they grow very fast – as quick as two weeks from preparing in fact! You can grow many of them indoors, but many species will also turn old logs and stumps into an edible feast. Fungi, after all, are nature’s recyclers.

Mushroom growing kits offer a variety of different types of mushrooms for you to grow at home. We’re using an oyster mushroom kit, which we’re going to grow in a two-gallon pot stuffed with straw, and a ready-to-go kit that uses coffee grounds as its growing medium.

Growing Mushrooms on Straw

Our oyster mushroom kit requires a large pot of around 10 litres (2.5 US gallons), or you could use two pots of half this volume each. The growing medium is straw, pressed into pellets and ready to be rehydrated. In most kits the mushroom spawn (or mushroom ‘seeds’) is inoculated into grains such as barley.

Clean the pot then sterilise with a dilute household bleach solution. Cover the drainage holes with a circle of cardboard cut to fit the base of the pot. Punch or cut three evenly-spaced holes of around a half inch (1.5cm) in diameter into the sides.

Empty the straw pellets into the pot then break up the packet of grain kernels and add it to the straw pellets. Mix well to evenly distribute the spawn. Make sure to use very clean hands for this so you don’t introduce any unwanted germs. It’s usually best to do this outside to avoid making a mess.

Very slowly trickle half a gallon of water over the spawn mix. Allow the water to become fully absorbed – which will probably take around around half an hour – then add the same volume again, slowly. Once the straw pellets have fully rehydrated to fill the pot, push back the straw from your three holes to leave a cavity. This will help keep this area moist and protected, so the mushrooms can properly develop.

Next you need to make a lid to prevent everything from drying out. A simple way to make one is to cut out a round of stiff cardboard to fit, then wrap this in clear food wrap or clingfilm.

Growing Mushrooms Indoors

Now the growing medium is prepared, we just need to offer warm conditions for the mycelium (or mushroom ‘roots’) to grow. Room temperature is ideal, but keep the pot away from direct sources of heat. If you’re growing during the summer you could keep the pot outdoors, somewhere sheltered and out of direct sunlight.

Mist-spray the holes in your pot a couple of times a day. This will prevent the straw from getting too dry and provide the moist environment that mushrooms need.

After about five days you should see that the grain kernels have already started to sprout white mycelium. After two weeks the straw should be totally white with mycelium. At this stage your kit is ready to produce its first flush of mushrooms!

Continue to mist the holes twice daily, and within a week or two you should notice small clusters of primordia (the beginnings of your mushrooms). At this stage misting becomes even more important as these mustn’t be allowed to dry out. They’ll swell into full-sized mushrooms within about a week of spotting the primordia.

The best time to harvest oyster mushrooms is before the caps have fully flattened out, otherwise they will dump lots of spores everywhere! Twist free the whole cluster at once – the mushrooms will be different sizes and that’s fine – and trim any stump out with a sharp knife, right back to fresh straw. Continue misting, and you can expect new mushrooms to sprout from the harvested hole in due course. They should keep cropping every few weeks for up to around 10 weeks.

Coffee Grounds Mushroom Kit

I hate waste, and my daily cup of joe creates quite a bit of it in the form of coffee grounds. But what if you could turn this waste into food? That’s what the coffee grounds mushroom kit does, using coffee grounds mixed with a little straw to create the ideal growing medium for our mushrooms.

Simply cut open front of box and cut a cross into the front of the bag. Soak the bag overnight, let it drain off, then pop back into the box. Mist the cut-open front of the box with water twice a day. Keep the kit on a windowsill or work surface out of direct sunlight, avoiding direct sources of heat.

About seven days after starting your kit off, you should see the beginnings of primordia. These grow very quickly, doubling in size almost every day! Within a week, it’s harvest time. Again, harvest the mushrooms when the caps have just started to open out but haven’t yet flattened. Flattened out mushrooms don’t store for long, and aren’t quite as firm and flavoursome. To harvest, simply twist and pull them away with your hands.

You grow a follow-on flush of mushrooms using this kit too. Allow the kit to rest for two days following harvest, then soak the block in water just as you did when you started it off. Weigh it down if necessary. Lift it out, allow the excess moisture to drain off, then pop it back into the box. As before, mist regularly. The second crop should follow on within a couple of weeks. And once you’ve had that harvest, repeat the process once more!

Quality mushrooms can be pricey, but by growing your own you can be sure of perfect ‘shrooms at peak freshness – and for a lot less than at the grocery store! They’re so powerfully good for you too: great for the immune system and for fighting off diseases. Have you grown mushrooms before, and what’s your favourite variety? Join in the conversation below! Have fun guys…