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Can Oyster Mushrooms Grow on the Ground?

If you’re new to mushrooms, you’ve probably never seen oyster mushrooms outside of your local grocery store’s produce section, even though they’re one of the easiest varieties of mushrooms to grow. This made me wonder… if they are one of the easiest to grow, then can they grow on the ground?

Oyster mushrooms are less likely to grow directly on the ground unless there is a substrate for them to grow on, such as decaying wood. In the wild, oyster mushrooms grow on wood, like fallen logs or living hardwood trees. Oyster mushrooms can be cultivated on substrates such as sawdust, coffee grounds, and agricultural byproducts like cotton waste.

Oyster mushrooms growing on a log

Let’s dig a little deeper to learn if oyster mushrooms grow on the ground, to find out what oyster mushrooms grow on, and see how long it takes oyster mushrooms to grow.

What do oyster mushrooms grow on?

Oyster mushrooms grow on certain trees and on various substrates. A substrate is any sort of organic material that mycelium (think of mycelium as the roots of the mushroom) can grow in or on. Depending on the location, oyster mushrooms have been known to grow well on maples, birches, sweetgums, willows, aspens, alders, and cottonwood trees.

Outside of forests, there are a variety of substrates that oyster mushrooms grow well on. Commercial and hobbyist mushroom farmers use logs, compost, wood chips, straw, organic material (like leaves and bark), toilet paper, and coffee grounds. Out of these, the oyster mushrooms do the best on logs and straw, but they can also thrive on straw and coffee grounds.

If you’re interested in growing your own oyster mushrooms but don’t feel like investing in a growing environment or hacking away at logs, then home kits are a great place to start! Companies like Back To The Roots offer cute little oyster mushroom grow kits that come in a cardboard box. Oyster mushroom kits are super user-friendly: just open the plastic-wrapped block of mushroom spawn by a window with indirect light and then mist the mushrooms twice a day as they grow.

How long does it take to grow oyster mushrooms in the ground?

Once we’ve got a proper substrate for the oyster mushrooms to grow in the ground, whether that’s a fallen hardwood log or one of the many types of substrate mentioned above, technically speaking the oyster mushrooms would not be growing just in soil but in a mix of organic material. But let’s move forward assuming the organic material is on the ground.

The fruiting process can be remarkably fast for oyster mushrooms in the right conditions. First, the oyster mushrooms need to be “pinned”, which is when the mycelium is shocked into forming clumps after it has adequately permeated its growing medium. To help the mycelium spread out throughout the substrate, commercial oyster mushroom farmers like to keep the growing environment in a constant temperature range of 78 to 84 degrees Fahrenheit with high humidity over 90% and high carbon dioxide content.

After 10-14 days in this environment, the mycelium has adequately permeated the substrate and is ready for pinning. Quickly dropping the amount of carbon dioxide in the growing environment shocks the mycelium into growing clumps of little mushrooms. After 7-14 days, the pinning process is complete and the tiny mushrooms are ready to grow.

Oyster mushrooms are phototropic, which means they grow towards light sources. Having a lighting system in the growing environment will help the tiny mushrooms grow upward and create their signature shape. A mister like those used to keep veggies fresh in grocery stores is usually used to keep the little mushrooms moist. There are also commercial humidifiers to keep relative humidity at an ideal level.

Now the mushrooms are ready for harvesting! Each block of mycelium-filled substrate can usually be harvested three times before the mycelium is depleted, with a new batch of mushrooms ready for harvest every 10 days or so for about 5-7 weeks. In total, that’s around 3-4 weeks of preparation for 5-7 weeks of oyster mushrooms ready every 10 days. It’s no wonder oyster mushrooms are popular given how fast they are to grow!

Final thoughts

While oyster mushrooms can grow on the ground, they’re way more likely to be found in the wild on decaying trees and logs. When farmed, either commercially or at home, oyster mushrooms will fare much better when grown in a wood or straw substrate than they will on the ground. Bottom line, it is possible to grow oyster mushrooms on the ground if there’s the right type of substrate underneath them. Whichever growing medium you chose, oyster mushrooms are easy to grow and great in recipes!