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How Long Does It Take To Grow Mushrooms? Here’s What You Should Expect

How much time it takes to grow mushrooms depends on numerous factors. Oyster mushrooms, a fast-growing variety, take only 2 to 3 weeks to mature. Meanwhile, you can grow shiitake mushrooms in a little over three months. The substrate you use can also make a big difference in growth speed.

Do Mushrooms Take A Long Time To Grow?

How long does it take to grow mushrooms? First and foremost, it depends on the species.

While you can grow oyster mushrooms in 20 days, it takes over 10 years to know if truffles will even fruit!

Your substrate (growing medium) can also make a difference, as does whether you start with spores, spawn, or a kit. 

Want to grow mushrooms quickly? If so, keep reading to learn about your growing options and some mushroom varieties. 

Spores Vs Spawn

What’s the difference between mushroom spores and spawn? Basically, spores are mushroom-made, and spawn are man-made, using spores. FreshCap Mushrooms demonstrates how to make grain spawn:

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It’s easier and faster to start growing mushrooms with spawn.

In the wild, mushrooms release countless spores into the air, so that a few might land in good habitats. 

Mushrooms in the wild
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But in captivity, people can add spores to substrates, allowing them to establish living cultures (mycelia). They can then “plant” the resulting spawn, somewhat like seeds.

Different kinds of mushrooms
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A major advantage of spawn over spores is that they can be cloned, whereas each spore is genetically distinct. This allows people to know a mushroom’s qualities before growing it, almost like how you can predict the future traits of a purebred puppy.

Save Time With Kits

A mushroom-growing kit can save you even more time than starting with spawn. Kits usually come pre-assembled, so you just spray them with water. With a kit, you may have mushrooms in only 10 days. 

Your Substrate Matters

Mushrooms digest whatever they grow in, which means a good substrate is highly nutritious. Options include logs, sawdust, coffee grounds, straw, and even toilet paper: 

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Please note that you must grow portobello mushrooms in compost, which is why I recommend using composted manure in this article

Intuitively, mushrooms tend to grow faster in soft or pelleted substrates. Oyster mushrooms, for example, only take 3 to 5 weeks to grow in these substrates:

  • “Masters mix” (sawdust and soybean hulls)
  • Woodchips
  • Straw 
  • Toilet paper

In contrast, growing mushrooms on logs takes at least 6 months. 

Keep Your Substrate Wet!

Since fungi need water (mushrooms are 70 – 90% water), you must keep your substrate wet. Additionally, you should sterilize or pasteurize your substrate before adding spawn so the mycelium will have a fighting chance against wild organisms. 


Unlike sterilization, pasteurization aims to reduce microbes in a substrate, not eliminate them. You can pasteurize a substrate in steam or hot water between 150 – 185 F (66 – 85 C) for 1.5 – 2 hours.

Pasteurization is appropriate for moderately nutritious substrates, which are less likely to be taken over by mold or bacteria. Non-supplemented straw is an example.


When highly nutritious substrates aren’t sterilized, they tend to be colonized by mold before intentionally-grown mycelia can produce mushrooms. You can sterilize a substrate by heating it to at least 250 F (121 C) for 2.5 hours at the pressure of 15 PSI (pound per square inch).


How Long Does It Take For Morel Mushrooms To Grow?

According to Thomas J. Volk from the University of Wisconsin in La Crosse, morel mushroom spores can grow into cells in 10 to 12 days, and they can mature into mushrooms in 12 to15 days. However, Mushroom Appreciation warns that they’re difficult to cultivate, sometimes taking years to mature in captivity.

How Long Does It Take To Grow Oyster Mushrooms?

Oyster mushrooms grow quickly even if you start from scratch. According to GroCycle, it takes about 2 to 3 weeks to grow one crop of them, and about 5 to 8 weeks to grow three. You’ll have to start over after the third harvest, as the mycelium will be exhausted.

How Long Does It Take To Grow Portobello Mushrooms?

Button, cremini, and portobello mushrooms are actually different stages of Agaricus bisporus. It takes between 3 and 4 weeks to grow portobellos (with pre-made compost). Note that full-grown portobellos are only possible during your second or third harvest, if allowed to mature.

How Long Does It Take To Grow Shiitake Mushrooms?

You can grow shiitake mushrooms in a little over three months with a kit. In contrast, growing them on a log can take over 18 months. However, you can harvest shiitake mushrooms 2 to 3 times a year for 3 to 7 years from the same log.

Growing Mushrooms Can Take Weeks Or Years!

Again, how long does it take to grow mushrooms? It all depends on the species, the substrate, and the growing conditions. If you want to grow mushrooms as fast as possible, here are some options:

  • Grow oyster mushrooms.
  • Start with a growing kit.
  • Use a nutritious substrate.
  • Don’t use logs as a substrate.
  • Choose spawn over spores.

Have any questions? Please let me know in the comments.

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About The Author

Nadya Jones

Nadya's the creative mind behind this blog, sharing her passion for landscaping, gardening and making spaces that nourish the soul. An entrepreneur and writer based in Raleigh, NC, Nadya turns imaginative ideas into inspiration, fueling home and garden dreams. Though Nadya crafts gorgeous posts and photos showcasing lush yards or blooming gardens, the real magic happens behind the scenes where Nadya's partner Brett provides endless support, implementing each vision with care and dedication. Brett's the one ensuring her creative concepts come to life. At heart, Nadya remains an imaginative soul, forever dreaming of whimsical details, vibrant hues and lush landscapes. Each manicured edge or blossoming bloom fuels inspiration, expanding her vision of what's possible in design and life. She shares her love for landscaping, gardening, and outdoor design in her blog, the one you are visiting right now. If you are interested in the same things, be sure to check it out! Also, follow Nadya on Facebook, Twitter, Instagram, Pinterest, Flickr, and LinkedIn!

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