Mushrooms are the fruiting bodies of fungi, and make an excellent substitute for meat, being high in protein, vitamins and minerals. Growing your own mushrooms at home is a great way to enjoy healthy harvests even if you don’t have a garden, and at any time of year. There’s lots of choice, too, so you can enjoy gourmet varieties such as oyster and shiitake, as well as the more usual button mushrooms. There are mushroom growing kits available to buy, which are great for beginners and make excellent gifts, too.
Mushrooms adapt to growing in different places inside or outdoors, which is useful for UK gardeners, especially in winter when home grown crops are in short supply. Indoor growing in a controlled environment gives the best results, where temperature and humidity can be controlled to optimum levels.
Types of mushrooms to grow
While there are many types of mushrooms that can be grown at home with care, these are the most straightforward ones to grow, and which are available as growing kits.
Button mushrooms are a familiar sight on shop shelves and thrive in dark, humid, and warm conditions.
Lion’s mane is also known as monkey’s head mushroom, due to its unusual cloud-like heads that resemble a flowing mane. This type is a little more challenging to grow, needing warmer temperatures to 25֯C, and high humidity.
Oyster mushrooms come in many different types with grey and pink oyster mushrooms the most straightforward to grow at home. They need some light and good humidity to grow.
In this short video guide, the experts at Caley Brothers share their top tips for growing mushrooms, including how much you should water them.
How to grow mushrooms
While the easiest way to grow mushrooms in the UK for beginners is to buy a growing kit that contains everything needed, there are other ways to grow mushrooms. You can buy mushroom spawn to grow in beds or boxes filled with a suitable growing medium which is usually known as a substrate, like compost or manure. Other possible substrates are a bucketful of fresh coffee grounds, if available from coffee shops, or straw. If you have access to recently chopped logs, you can buy wooden dowels or plugs that have been impregnated with spawn, which you tap into pre-drilled holes in the log.
Where to grow mushrooms
Mushrooms are best grown undercover, where temperature and moisture can be controlled. A shed, garage, garden cold frame or cellar will work well – anywhere out of the sun where it's possible to give mushrooms their optimum growing temperature of a minimum of 15°C, and a few hours of light (which can be artificial) per day. Outside, grow mushrooms in beds, on compost heaps, or in logs.
Growing mushrooms in beds or boxes
A rich, fertile, moisture-retentive growing medium is needed for mushrooms. The traditional material for growing mushrooms is horse manure and you can buy this from your local garden centre or nearby stables. If the manure is fresh, pile it into a heap and fork it over to mix well every couple of days for a fortnight until the heap has cooled and settled.
Ensure the growing medium is moist. Spread the spawn across the surface and mix it 5-8cm deep, then cover with damp newspaper.
After several weeks when white thread-like mycelium has appeared, take off the newspaper and cover the mycelium with a 2-3cm layer made up of 50 per cent garden soil or compost mixed with 50 per cent lime. Mist or water as required to keep this evenly moist, using either a hose fitted with a spray attachment, a watering can fitted with a fine rose, or a hand mister. Mushrooms should start appearing from several weeks after sowing.
How to grow mushrooms on logs
While growing mushrooms on logs is straightforward as the logs need little attention once the dowels are inserted, you do need to supply and drill your own logs. These need to be hardwood, not conifers, and cut from healthy wood. Logs need to be freshly cut, and the dowels implanted no more than six weeks after cutting. The best woods to use are oak, beech, hornbeam, chestnut, hazel, birch, maple or holly. Logs should have a diameter of 10-15cm and be 45-60cm long.
Drill holes along the length of the log, 15cm apart and in rows 8cm apart. Insert the impregnated dowels fully into each hole. Some kits come with sealing wax, so seal each one with wax if directed to. Place the log in a shady spot, under trees or shrubs, with one end on the ground and the other propped up, and ensure it stays moist. Mushrooms can take up to 18 months to appear.
How to grow oyster mushrooms
Buy a pack of oyster mushroom spawn, along with some straw. Soak the straw in water overnight to make sure it's thoroughly damp, discarding excess water. Mix the mushroom spawn with the damp straw and then pack it into a polythene bag, such as a bin liner. Seal and leave for six weeks in a damp, sheltered spot between 20-25ºC, such as near your compost heap. As the straw breaks down, the mushroom spawn will grow into it, colonising the straw.
Here, Monty Don demonstrates how to grow oyster mushrooms in straw:
After six weeks the oyster mushroom spores will have colonised the straw in the plastic bag. Move the bags into a light, warm and moist environment, such as your greenhouse. Cut slits in the bag so the oyster mushrooms can grow through them.
Monty Don checks on the progress of his oyster mushrooms:
After two weeks, check the bag to see if oyster mushrooms have developed. The straw should continue to produce mushrooms for several weeks.
Growing mushrooms from mushrooms
It is possible to grow mushrooms from mushrooms but this needs more care and input than some other methods. You’ll need freshly bought organic mushrooms, straw soaked in water for a couple of days, and a lidded container such as a deep plastic box with holes made in the lid. Using a sharp knife, cut the stem ends into small slices and layer into the moist straw, then keep dark and moist. Mushrooms may start to form after a few weeks.
How to harvest mushrooms
Mushrooms grow quickly, so check them daily and harvest them as soon as the mushrooms are large enough to eat.
Some types, such as button mushrooms, should be harvested using a sharp knife to cut the stem cleanly at the base, which encourages regrowth. Others, including oyster and lion’s mane mushrooms should be harvested by holding the clump and twisting one full turn to loosen from the substrate.
How to store mushrooms
Mushrooms have a high moisture content, so store them in a paper bag in the fridge or in an uncovered container. Keep them on a fridge shelf rather than in the drawer compartment.
Advice on buying mushrooms
- Mushroom spawn and dowels are available by mail order from specialist mushroom suppliers and from some vegetable seed suppliers
- Make sure you buy the right mushroom kit for your needs and space. Success depends on providing the perfect conditions for your mushrooms to grow
Where to buy mushrooms
Looking for inspiration on how to use your crop? Our friends at olive have curated a delicious collection of mushroom recipes, including a creamy mushroom risotto.
Frequently asked questions
Can you plant supermarket mushrooms?
Yes, but you may get better results when growing mushrooms from a growing kit. Use fresh, organic supermarket mushrooms for the best chance of success, and follow the instructions above.