What Is This Thing in My Yard (Garden, House)?

by Michael Kuo

Many amazing and wonderful mushrooms are notorious for appearing in people's yards and gardens, or even in their flower pots or basement carpets. This page is meant to help you figure out what kind of mushroom you have been blessed with. I have included photos and brief descriptions, in the right-hand column, for a few dozen of the most common yard, garden, and household mushrooms in North America. Below, I have written extended answers to many of the questions I frequently receive in lawn and garden mushroom e-mails.

The odds are high that your mushroom is featured on this page--but just about any mushroom could conceivably pop up in your yard, especially if your yard or garden is near a stand of trees or a forest. Many people do not know that mushroom identification is extremely difficult--not at all like identifying, say, trees. There are about 200 (natural) species of trees in North America, and a good field guide can usually help you figure out what tree you're looking at. In contrast, no one knows how many mushroom species there are (estimates range as high as 30,000 for North America); scientists do not even agree on what constitutes a "species" of mushroom or on how they can be identified; and most of the species that have been named so far require microscopic analysis for positive identification.

So, I hope it is obvious that comparing mushrooms to a few photos on the Internet is a very tentative way of identifying them. You're not going to reach a "scientific certainty" about your mushroom, no matter how much it looks like the picture. But if you find mushrooms and their identification interesting, I invite you to explore this Web site (the home page is a good place to start) and the wonderful world of mushrooms!

How Do I Get Rid of Them?

The short answer is: You can't, unless they're in your house--in which case, get out your pocketbook and call the contractors. The long answer follows.

But before I explain why you can't get rid of your mushrooms, please take a moment to consider that you have come to a mushroom lovers' Web site (or you have contacted me or a mycologist and been directed here), wondering how to kill mushrooms. It's a bit like going to or contacting BaldEagleInfo.Com and asking them how to shoot eagles. I used to send out a pretty snitty form e-mail ("Dear Sir or Madam") to people who asked me how to kill mushrooms, but I realized I was being a bit of a jerk, and that people deserve a decent explanation.

The "mushroom" you are wondering about is only the tip of the organism's iceberg. Mushrooms are roughly comparable to apples on apple trees; they are the fruiting body the organism creates when it wants to reproduce. The apple tree's "plan" (I know; I'm giving human thoughts to trees and mushrooms, but it's the easiest way to talk about this) is to put its seeds in a nice, plump morsel that will fall to the ground and attract a hungry animal who will then, um, pass the seeds to new territory for germination and a new apple tree.

Mushrooms have similar plans. Their seeds (microscopic things called spores) cover parts of the mushrooms; one of the best ways to understand mushrooms is to think of them as "spore factories." The entire structure is an excuse to get spores out into the world. Gilled mushrooms drop their spores into air currents, where they are lofted to new environments; stinkhorns cover themselves with foul smelling, spore-soaked slime that attracts insects, who carry the spores away on their legs and wings.

The "real" organism--the part that corresponds to the apple tree, rather than the apple--is called a mycelium (pronounced so it rhymes with "my helium"), and it is found in the mushroom's substrate: the ground, leaves, a log, woodchips, and so on. It is a mesh of tiny, threadlike cells that plow through the substrate, consuming nutrients.

You may have heard of the "world's largest organism," the Honey Mushroom. Some scientists in the Pacific Northwest discovered that a single honey mushroom mycelium stretched for miles, running between trees. The scientists calculated a probable biomass for this mycelium and came up with an organism weighing far more than anything else on earth. To be honest, there are probably bigger mycelia (the plural of mycelium) on our planet--and if they had calculated the biomass of a Quaking Aspen stand somewhere they might easily have come up with a heavier organism, since aspens often clone themselves over and over again. But the point is that a mushroom's mycelium can be huge and extend for amazing distances.

Now it should be obvious why you can't get rid of your mushrooms; you would have to get rid of the mycelium rather than the mushrooms. If you have been picking or stomping on your mushrooms to make them disappear, you might as well have picked every apple in an orchard, trying to make the trees go away.

You would need to remove all the soil and natural debris in your yard or garden, and replace it with something inorganic like concrete or plastic--in which case you would no longer have a "yard" or a "garden," but you would probably be mushroom free. I say "probably" because Pisolithus tinctorius, Scleroderma polyrhizum, and other mushrooms might still manage to erupt through your concrete!

In your house, you may have better luck getting rid of mushrooms. But you can see why I said, above, that you'll need to get out your pocketbook. Your mushroom's mycelium is growing in wood or carpet, and you'll need to replace everything in the vicinity: the carpet, the floor, the subfloor, the woodwork . . . and you will need to ensure that moisture is not present in the new materials, which means fixing the leak or humidity problem that encouraged the mycelium in the first place.

Your Yard NEEDS the Mushrooms

What I haven't mentioned yet is that your mushroom is an integral part of your yard or garden's ecosystem. Its mycelium is probably doing one of two things, either of which is crucial to the health of your yard:

  • Saprobic mushrooms help decompose dead organic material. Their mycelia chew up fallen leaves, dead blades of grass, woody debris, dead rootlets, and so on, returning this material to the soil. Imagine what would happen if nothing decomposed in your yard or garden: stuff would eventually pile up sky high! Yes, you can remove dead organic matter yourself--but your rake merely carries leaves away, rather than breaking them up into natural, soil-enhancing particles.

  • Mycorrhizal mushrooms are involved in symbiotic relationships with plants and trees. The plant's rootlets are surrounded and protected by the mushroom's mycelium, which helps the plant absorb water and nutrients; in exchange, the fungus gets sugars and amino acids. Most trees cannot survive without mycorrhizal partners from the fungal world.

As you can see, removing mushrooms from your yard is probably not a good idea if you are at all concerned about maintaining a naturally healthy ecosystem.

But They're Invasives

No; your yard is the invasive. Your grasses, flowers, vegetable plants, and ornamental trees are anything but natural to your area. In short, you have taken a big chunk of an ecosystem and deliberately destroyed it, planting not only your house, but invasive species everywhere. I don't mean to be confrontational here--and I do own a home with a yard full of non-native organisms. But we should be honest about what's going on, rather than pretending that our artificially created environments are "natural," while the weeds and mushrooms are "invasive."

If your mushroom is actually a species that does not belong in your area, it is probably only there because it is attending to something non-native that you put there. Your mulch may be cypress mulch. Do cypress trees grow in your area? Woodchips and mulch from Home Depot or Wal-Mart come from who knows where, and they are often accompanied by invisible mycelia. This is how the tropical and subtropical stinkhorn Phallus rubicundus, for example, winds up in northern Illinois gardens.

Now stop for a moment to think about how ironic it is that we often create woodchip trails through our forest preserves in an effort to keep people from tramping through the woods and harming the ecosystem!

I'm Afraid to Touch Them

Don't be. No mushroom is so poisonous that handling it is dangerous, providing you don't lick your hands clean when you're done. Just wash your hands and go about your business.

Is My Tree Going to Die?

A few mushrooms are neither saprobic nor mycorrhizal (see above), but parasitic. Their mycelia subsist at the expense of a living substrate, which might include the roots and heartwood of living trees. Armillaria mellea and Armillaria ostoyae are among these mushrooms, and are commonly encountered in urban settings.

Before you freak out, however, note that there are many species of Armillaria, some of which are harmless saprobes, and that the species are very difficult to identify (this Key to Armillaria demonstrates the difficulty). Armillaria tabescens, for example, is quite common in eastern North America's yards, but is a harmless consumer of already-dead material. And, note that there is still no plausible way to remove the mycelium. If the mushrooms are appearing, a parasitic mycelium has been hard at work for quite some time, anyway, and the damage has already been done.

More confusing than species of Armillaria when it comes to this question are various species of Polypores, which can don more than one ecological "hat" and exist as harmless saprobes or pathogenic parasites. If you have the Chicken of the Woods (see Laetiporus sulphureus and Laetiporus cincinnatus), the Hen of the Woods, or Polyporus squamosus growing from your tree (among many other polypore species), your tree may be at risk--or it may simply have some deadwood that is being harmlessly decomposed by the fungus.

I'm Worried about My Children (Or Pets) Eating Them

So am I. Many mushrooms are poisonous, including some of the species that frequently come up in yards and gardens. However, if you read the material above, you can see that your only option is to teach your children (or train your pets) not to eat mushrooms they find in the yard--and, if they are not learning this lesson, not to let them play in the yard unsupervised.

You cannot get rid of the mushrooms permanently, and the time you would spend on your hands and knees trying to pick every tiny mushroom you could find before letting your child or dog into the yard would be ridiculous; why not just spend that time with the child or dog, and keep an eye on things?

Contrary to popular belief, animals have no innate sense of toxicity, and the only animal that has any ability to reliably avoid eating toxic substances, Homo sapiens, accomplishes this miracle with cognition rather than instinct. Some folks who are interested in eating wild mushrooms believe that if they find mushrooms that have been nibbled on by deer or squirrels, the mushrooms must be edible. This is a very dangerous assumption, since a dead deer or some very sick squirrels could be a stone's throw away.

Thus your dog cannot be trusted to eat only what's good for him--a fact already familiar to most dog owners. Every time my friend's dog comes to my house, it runs straight to the litter box to eat all the cat poop . . . but I digress. The point is, dog owners have to remove potential poisons from their dogs' environments. Easy enough, in the house. But the mushroom-filled yard is another story and, at the risk of sounding heartless, I'm afraid you will have to keep a constant eye on your dog, or just accept the risk and let him sniff around without you.

Your child, however, has a brain that is much bigger than a walnut, and she can be taught to avoid mushrooms on her own. People regularly teach their children that certain things are dangerous: light sockets, medicine bottles, tools, knives, and so on. You will need to add mushrooms to the list. I am aware that there is a cut-off point, age-wise, under which such lessons cannot be learned. For children this young, you will need to do more or less what you do with the knives and medicine bottles: keep them away from your child. But child-safe drawers and safety caps won't work with mushrooms, as we've seen, and you'll have to keep your child away from the mushrooms, rather than vice-versa.

Mushroom Fun for Kids

I hope you will consider using the mushrooms in your yard to help your child have fun and educational experiences. I know one person whose childhood dream was to become a mycologist--and she is well on her way, studying mycology in a prominent school for the science. Maybe your child will be the next great mycological star! And besides, mushrooms are way more interesting than stupid old dinosaurs, fire trucks, or stethoscopes.

Where Will They Come Up Next?

Keep track of mushroom appearances. Do different kinds come up in different areas of the yard? Use toothpicks or little flags to mark mushroom spots. Do any patterns develop? Do weather factors influence the appearance of mushrooms? Can you find any Fairy Rings? If you have a fairy ring in your yard, does it appear every year? Does it grow from year to year?

Make Spore Prints

A Spore Print is easy and fun to make. How many different colors are represented by the spore prints you can make from mushrooms in your yard?

How Long Does the Smelly Slime Last?

If you are lucky enough to have stinkhorns in your yard, can you figure out how long it takes the insects to remove the foul-smelling slime covering the surfaces? Can you manage to take a photograph that actually captures the insects on the mushroom?

What Kind Is This?

Here is part of an e-mail I recently received. I have heard similar stories many times over the years.

    At my eight-year old daughter's insistence, I bought her a mushroom identification book. I was pretty sure she just liked the pretty pictures, but we've had a great time the last month traipsing through our woods and some nearby trails looking at mushrooms and fungi. We've set up a webpage with some of the pictures we've taken . . .

Mushroom Fun for Grown-Ups

I once made collections of 14 different mushroom species in my yard, in one day. It took hours, as I crawled around on hands and knees with my camera and collection bags, taking notes and documenting the details that are necessary for mushroom identification. This was nearly two years ago, and I have successfully identified eight of the mushrooms so far. The other six collections are still waiting; some day this winter I will have a day off and, unless the Steelers are playing, I will get to spend hours with my microscope and mushroom books, still playing with my yard's mushrooms!


Mutinus species
"Looks like a carrot" . . . "Looks like a dog's -----" . . . "Smells terrible!"

Clathrus crispus
In FL and Gulf Coast . . . Similar, in CA

Clathrus species

Phallus impudicus

Clathrus columnatus
SE North America

Lysurus species 01

Leucocoprinus birnbaumii
Leucocoprinus birnbaumii
Little yellow guys in gardens and flowerpots.

Amanita thiersii
Shaggy and soft . . . TX to OH.

Chlorophyllum molybdites
Stem not shaggy. Greenish mature gills.

Coprinus comatus
Gills turn to black goo.

Leucoagaricus americanus
Stains yellow, then red.

Agrocybe pediades
Small, gills brown.

Conocybe apala
Tiny and fragile, gills cinnamon brown.

Panaeolus foenisecii
Tiny and fragile, gills dark brown to black.

Morchella rufobrunnea
West Coast, winter and spring.

Fuligo septica
"Looks like a vomit patch."

Cyathus striatus
"Tiny eggs in a tiny nest."

Scleroderma polyrhizum
Baseball sized, very tough.

Calvatia cyathiformis
Inside purplish when old.

Calvatia craniiformis
Inside olive brown when old.

Peziza domiciliana

Other inside mushrooms include small species of Coprinus (usually in damp bathrooms or basements) and, on furniture or woodwork, Oyster Mushrooms.

This site contains no information about the edibility or toxicity of mushrooms.

Cite this page as:

Kuo, M. (2006, October). What Is This Thing in My Yard (Garden, House)? Retrieved from the MushroomExpert.Com Web site:

© MushroomExpert.Com