Much has been written on how to craft an attractive terrarium—but mushrooms are often overlooked. Under the right conditions, funky fungi can be cultivated inside lush, mossy terrariums, adding a unique touch to your miniature habitat.
Some terrarium purists consider ‘shrooms a sign of aesthetic failure. However, unexpected mushrooms can actually signify an ecosystem that’s working exactly the way it should: recycling dead or decaying plant matter and returning nutrients to the soil. Mushrooms may sprout out of your terrarium’s moss, emerge from rotting wood such as sticks or tree bark, or pop right out of the soil itself. And if you’re a toadstool enthusiast, you can even design your miniature environment specifically to foster mushroom growth. Just be sure you don’t touch any that you aren’t positive are safe, and definitely don’t eat them without expert guidance.
What mushrooms love most
Building a basic terrarium is simple: layer soil, stones, and moss or other greenery inside a large container, add a misting of water, seal it tightly, and place it in the sun to create a miniature, self-regulating biosphere. But before you start encouraging mushroom growth, it’s important to understand what they are and how they thrive. All mushrooms come from mycelium—a spongy network of white fungus strands typically found in fertile soil, on the roots of trees, and inside rotting organic material. Although fungi aren’t technically plants, you can think of mushrooms as the “fruit” this mycelium produces.
Growing mushrooms in a terrarium means starting with mycelium and optimizing the conditions for mushroom growth by adding water, warmth, and food (organic material). Keep in mind that mycelium can take months to produce mushrooms, especially if there’s no decaying plant matter to feast on. When mushrooms do sprout, they’ll only last for a couple of weeks before decaying—but the mycelium they grew from will stay in your mini ecosystem indefinitely, sending up new mushrooms several times a year.
Unfortunately, this cycle of decay and regrowth means it’s nearly impossible to curate a terrarium that features your favorite fungus year-round. The good news is that the warmth and moisture of a regular terrarium provides a great habitat for mushrooms, so you can enjoy its mossy charm even when there are no mushrooms in sight.
Water and wait
The easiest way to grow mushrooms in a terrarium is to construct it, water it, and wait—mushrooms may sprout naturally from the mycelium in your mini ecosystem’s soil. Fungal spores can also travel through the air, meaning you may be “planting” mushrooms in your terrarium without even knowing it.
[Related: Seed banks are full of hidden fungi, and scientists love it]
If you’ve waited a few months without seeing any mushroom growth, try moving your setup into the shade. This won’t be great for the plants in your terrarium, but their loss could be the mycelium’s gain. Because mushrooms consume and decay organic material, they pop up where dead things are. Mushrooms also thrive in darkness; unlike plants, they can grow without sunlight. If your terrarium greens wither away and there are still no mushrooms in sight, try boosting the odds with some of our other tips below.
Put compost inside your terrarium
If you have a compost pile, you may have noticed mushrooms popping up in it from time to time. You can create the same thing in your terrarium: a moist, warm environment filled with dead and decaying organic matter. Rather than waiting for mushrooms to sprout on their own, try placing a few handfuls of compost into the terrarium to kickstart the process.
When we think of compost, many of us imagine food scraps like stale bread, vegetable peels, and old fruit. However, these edible offcuts are more appealing to mold than to fungi because of the nitrogen they contain. Mycelium does best in materials naturally found outdoors, like leaf litter, lawn clippings, and dead wood. A clump of wet leaves and tree bark is a good way to start composting in your terrarium. And although animal manure is commonly found in gardens and may even be in your compost pile, don’t attempt to grow mushrooms with it: the ones that appear may be poisonous.
Source your ‘shrooms from nature (with caution)
If you know where to look, you can source your terrarium materials from nature. Your backyard may have the mycelium you need to start growing mushrooms, but you’ll need to be cautious and understand the law if you go searching in parks or nature preserves. Many protected natural spaces have rules about what you can take home, if anything, and some wild mushrooms are poisonous and shouldn’t be handled with your bare hands.
That said, organic materials from nature can help jumpstart the process. Soil from around the base of a tree, for instance, is a lot more likely to contain mycelium than bagged potting soil from the store, and a chunk of rotting wood from a fallen tree is an ideal substrate for natural mycelium growth. If you can break off a small piece without breaking the law or disturbing the ecosystem around it, add it to your terrarium and see if mushrooms begin to grow. Grabbing a full-bodied mushroom from outdoors and sticking it in your terrarium won’t work. The key is to get the mycelium into your ecosystem—the “fruit” alone will just wither away in a few days without a support system under the soil.
Again, use caution. Be smart. Taking a small, damp stick home that you grabbed off the forest floor? Probably fine. Uprooting a healthy tree to scrape that sweet, sweet mycelium off its roots? Not fine. Not cool. Also, more trouble than it’s worth! You can buy mycelium online with way less effort, and even eat the mushrooms it grows. In fact, that’s our final tip for encouraging mushroom growth at home.
Grow like a pro by spending some dough
There’s one more way to add mycelium to your miniature ecosystem: hop online and buy some. Mycelium is sold in the form of white flakes or bricks that may need to be broken apart and soaked in cold water before planting. Start with a few small pieces and bury them in the soil, moss, and plant matter in different areas of your terrarium.
[Related: 4 benefits of eating mushrooms]
It will still take a while for mushrooms to appear, but this method gives you the highest chance of seeing results. Store-bought mycelium is designed to be easy to grow, and is even available in different varieties depending on what types of mushrooms you’re hoping to see. With some water and patience, you may soon see chanterelles, shiitakes, porcinis, and more.
Terrariums are beautiful, but mushrooms are fleeting—and many varieties may just not be suited to the bright, sunny conditions that the rest of your little ecosystem needs to thrive. If you’re really eager to see mushrooms, grab the rest of that store-bought mycelium and put it in a dark, cool place. Read the packaging, too—your mycelium brick probably has instructions on how to coax forth delicious fungi. In the meantime, your terrarium can sit in the sun until its own mushrooms appear.