Do Mushrooms Need Soil To Grow? The Facts Explained

Have you ever looked around and realized that mushrooms are growing in strange places? Perhaps they’re growing from a wooden pillar in your house, next to your houseplants, or on the trees outside. So you might be wondering, can mushrooms grow anywhere, or do they need soil?

Mushrooms don’t need soil to grow, as they can grow on any organic substrate. They can grow on wood chips, logs, leaves, mulch, compost, straw, etc. As long as there’s organic material that can provide nutrients, mushrooms will grow properly.

In the rest of this article, I’ll explain more about whether mushrooms need soil to grow, their requirements to grow, and what materials you can use to grow mushrooms. I’ll also discuss how you can grow mushrooms at home. If this interests you, keep reading!

Why Mushrooms Don’t Need Soil To Grow

Unlike many plants, mushrooms don’t necessarily need soil to grow. While plants use nutrients absorbed from the soil and sunlight to provide energy, mushrooms use decaying organic matter as their nutrient sources. The process of growing plants or fungi without soil is known as hydroponics.

Mushrooms mainly require five macronutrients and a few trace elements to grow. Here are the five nutrients that most mushrooms in the wild need to grow:

  • Nitrogen (N)
  • Potassium (K)
  • Phosphorus (P)
  • Carbon (C)
  • Magnesium (Mg)

These elements are often produced by the natural decomposition of organic material. So mushrooms may grow out of dead logs, wood chips, or even trees in the garden if there’s some decomposition. 

You can also grow mushrooms from coffee grounds or straw. However, if you’re looking to grow your own mushrooms, a log or wood of some kind is the best substrate for mushrooms.

What Is a Substrate?

According to the Cambridge Dictionary, substrate is “a substance or surface that an organism grows and lives on and is supported by.” In simple terms, a substrate is a material or surface where a living organism grows and gets its nutrients.

For most plants, the soil is that substrate. They get most of their nutrients from the soil itself. However, mushrooms grow from spores, so they don’t need soil. Mushrooms get their nutrients directly from decaying organic matter, usually plant matter.

So, for mushrooms, the substrate could be any organic material they can decompose to absorb nutrients. Wood is usually the best substrate for mushrooms, so you’ll often see them growing on trees or logs in your garden.

How Do Mushrooms Grow Naturally?

Mushrooms grow naturally from fungal spores, which land on different surfaces. If the surface they land on has enough organic matter and water, the spores grow into fungal mycelium.

Additionally, mushrooms produce millions of spores daily, but not all form new growths. Usually, only 2-3% of these spores will actually grow into new fungi. For the spores to grow, they need the ideal combination of: 

  • Dampness
  • Darkness 
  • Organic material
  • Temperature

If these conditions are met, the spores can form new fungal mycelium in a matter of weeks, with mushrooms sprouting soon after.

Is It Safe To Eat Wild Mushrooms?

Many mushrooms grow wild in forests or lawns. While some may be safe to eat, many are poisonous. Even safe-to-eat mushrooms can sometimes cause digestive issues, so avoiding them is best.

Some mushrooms, like oyster mushrooms or maitake mushrooms, can be found in the wild. These are safe to eat, although you should wash and cook them thoroughly to eliminate any lingering bacteria or dirt. However, mushrooms like the Death Cap, Autumn Skullcap, or False Morels are extremely poisonous.

The main problem with picking wild mushrooms is that many poisonous ones look similar to other non-poisonous varieties. False morels, for example, are extremely dangerous but look almost identical to true morels, which are safe to eat.

If you’re unsure whether the wild mushrooms in your area are safe to eat, it’s best to avoid them completely or consult with a professional.

How To Grow Mushrooms at Home

Luckily, you can grow mushrooms at home instead of relying on wild ones. Mushrooms are usually quite easy to grow, and even beginners can grow a good crop.

You might want to try a mushroom grow kit if you’re just starting out. For example, the Back To The Roots Mushroom Grow Kit, available on Amazon, is perfect for growing Oyster Mushrooms. This beginner-friendly Mushroom Grow Kit contains a substrate that already has oyster mycelium on it. All you need to do is provide water, and your mushrooms will grow well!

However, if you’re ready to grow mushrooms without a mushroom growing kit, here are the steps to follow:

1. Choose Which Mushroom To Grow

The first step is to choose your preferred mushroom. If you try to grow multiple types, you’ll unnecessarily complicate things. Start with one mushroom type that you like, and later you can add more.

A few popular choices for first-time mushroom gardeners are:

  • Oyster mushrooms
  • Shiitake mushrooms
  • White button mushrooms
  • Wine cap mushrooms
  • Lion’s mane mushrooms

2. Buy Spawn From a Reputed Seller

Spawn is a substrate that already has mycelium growing on it. This mycelium is kept in stasis until you’re ready to cultivate it. The mycelium grows and forms beautiful mushrooms when you transfer it to another substrate.

You can contact local businesses for spawn or use online merchants.

3. Buy the Needed Growing Medium (Substrate)

The next thing you need is a proper substrate. The substrate you choose will depend on the kind of mushrooms you want to grow. Each mushroom type prefers a different kind of substrate.

To make things a bit easier, I’ve listed some of the best substrates for the five mushrooms I mentioned earlier.

Mushroom TypePreferred Substrate(s)
Oyster mushroomsCotton Seed, Paper Waste, Sawdust
Shiitake mushroomsOak Sawdust
White button mushroomsHorse Manure mixed with Straw
Wine cap mushroomsHardwood Chips or Shavings, Straw
Lion’s mane mushroomsHardwood Sawdust supplemented with Wheat Bran

Note: These are recommendations only.

4. Select a Damp, Dark Place, and Grow Your Mushrooms

The next step is to select a proper place to grow your mushrooms. This could be a basement or any room that’s relatively dark and damp. You could even choose a cabinet or cupboard.

Place your substrate there to grow and regularly check on it. Spray water occasionally to prevent it from drying out. Mushrooms grow very fast, so in a few weeks, you should see a new set of mushrooms!

Can Mushrooms Grow in Just Water?

Mushrooms can grow in just water (also known as growing hydroponically), but they need an organic substrate, as they can’t grow in water alone. Mushrooms grow from mycelium, which grows in organic substrates as a network of thin, string-like structures.

Although you can grow mushrooms without soil, you still need a substrate. Water alone is not enough to grow mushrooms.

Final Thoughts

Mushrooms grow in any place with easy access to organic matter and water. Many mushrooms grow well even without soil since their nutrient sources are the organic materials they decompose.

Since growing mushrooms hydroponically is fairly easy, there are several mushroom grow kits and materials that you can use to grow them at home. All you need is a damp, dark place, a way to (somewhat) control the temperature of your location, and your mushroom growing supplies.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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