Mushrooms in the lawn may cause many different reactions depending on the individual. The fungi obsessed may marvel at the new species that popped up overnight, while the gardener or homeowner may sigh and be plotting how to rid them for good. Others may be rightfully worried that they could pose a significant health risk to their toddler or pet.
There are a variety of mushrooms that commonly show up in lawns and gardens. Some of them are harmless, and some of them are deadly. Some of them are exotic and last only a few days, and some of them are are regarded as pests that can destroy vegetative growth and wreak havoc on healthy gardens and may persist for long periods of time.
In this article, we are going to take a look at the six most common mushrooms that grow in the yard. Then we will explore the seven most common poisonous mushrooms that account for nearly all reported child and dog poisonings. We will end discussing why they grow, what to do about them, and some precautions and steps to take to minimize the chance of any mushroom poisonings.
Shaggy Mane, Coprinus comatus
This interesting mushroom is also known as shaggy ink cap and lawyer’s wig. It commonly grows alone or in clusters or rings in lawns and on the side of gravel roads and flowerbeds. It is edible and well-known in China for its great taste, where it is cultivated for food. It does not keep well, rapidly disintegrating once it is picked or once it releases spores. When young, they will last about 48 hours in the fridge.
It grows as a cylindrical cap anywhere from 3-15cm in diameter that opens up into a bell shape as it ages. The caps are white and scaly and the gills are initially white and turn pinkish then black with age. The gills secrete a black liquid filled with spores when the mushroom decomposes. As such, the spore print is black.
Stinkhorn, Mutinus caninus
Stinkhorns are a group of fungi in the Phallaceae family common east of the Rocky Mountains in the summer and fall. These exotic-looking fungi are found in shady damp mulch and compost piles in yards, gardens, and parks. The stinkhorn is a unique mushroom with an accurate name. It is known for its characteristic, putrid smell originating from a slime that covers its fruiting body at some stage of development. The particular species above has a horn-like appearance, growing from an oval structure called an “egg”. This smell helps attract insects like flies that allow it to distribute its spores. Stinkhorns are not poisonous to humans, pets, or nearby plants, and when found in the yard, are probably going to be around for only a few days.
Pinkish to orangish spikes 4-17cm high with a spongy texture originating from white “eggs” in the ground. Olive-brown slime covering 2-3cm of the tips. Sack-like vulva at the base of the spike.
Puffballs are common spherically-shaped mushrooms found in lawns in the warm, rainy late summer months. While they are usually less than an inch in diameter, the giant puffballs, or Calvatia gigantea, can reach over 12 inches in diameter. They are generally non-poisonous and not considered pests in lawns. Some puffball species (including the giant puffball) can be eaten while young and have a mild, earthy flavor and a spongy texture that soaks up sauces. Later in their maturity they are non-edible, tough and woody. Some puffballs look similar to immature deadly mushrooms like the death cap and destroying angel. To differentiate, foragers will cut the mushroom in half lengthwise. Puffballs will be all-white inside and show no signs of gills.
White or off-white color inside and outside.Rather than the common mushroom shape of open caps and exposed gills, puffballs produce their spores internally and release them when they split open near the end of their lifecycle. After maturing, they are yellowish on the inside with purple or green spores.
Although the name seems friendly, these mushrooms are dreaded in gardens around the world. This parasitic fungi of about 10 total species lives on trees and woody shrubs, usually in clusters. It is one of the most destructive fungi in gardens, where it attacks and kills the roots of plants and coniferous trees and decays the organic matter, otherwise known as white rot root disease. It is one of the largest living organisms in the world, researchers have found that its mycelium have been known to stretch over a few square miles. Bioluminescent. It is widespread throughout Britain, Ireland, some parts of mainland Europe, and North America. They are edible and known for their sweet, nutty flavor.
The honey fungus has a convex cap is 5-15cm in diameter and ranges from yellow to red-brown with darker shades in the center. Stems are white when immature but turn yellow or yellow-brown with age. There is a pale yellow stem ring. Gills are attached. Spores are pale creamy white. The mycelium is black.
This mushroom is aptly named because it commonly meets its demise from the rotating blade of lawnmowers across North America. Extremely common little brown mushrooms (LBMs) widely scattered on lawns, meadows, and grassy areas. Found from early summer to fall. Possibly psychoactive, not recommended for eating. Can cause sickness in animals and toddlers.
This mushroom has a small size (1.5-3cm cap, 6-10cm stem). It’s habitat is solely grass. Spore print is dark brown to purplish brown. No partial veil or ring on stalk. Cap is conical or convex, sometimes with a central hump. Cap changes color as it dries out, changing from dark brown to pale grayish, tan or buff in shades.
Very common small and fragile mushroom found in North America and Europe growing in short, green grass. Pops up commonly in humid, rainy weather. Might grow in the yard on sunny mornings while there is dew and disappear by the sunny afternoon. Can be found from spring to the end of fall. It is toxic (contains trace amounts of phallotoxins) but not known to be deadly.
Cap is pale cream to silvery-white and sometimes darker in the middle. Hood-shaped conical cap is up to 3cm in diameter, flattens with age. Gills are free and visible, release spores that are brown to reddish-brown under spore print.
These species account for the overwhelming majority of mushroom poisonings and fatalities among toddlers, dogs, and even adults. If you suspect these might be in your yard, be sure to remove them from the base as soon as possible and keep a close eye on playing children and dogs.
This genus of mushroom includes the most dangerous yard mushrooms. We will be focusing on four toxic varieties, the death cap and destroying angel, panther cap, and fly agaric.
Death caps are the number one cause of fatal mushroom poisonings in the world, due to their amatoxins that cause liver and kidney failure. Death caps were originally found in Europe, but are now distributed worldwide and are becoming increasingly more common in the western United States. They can be found growing around grassy areas in lawns and parks or at the edge of woodlands near oak trees in the autumn.
The cap has a diameter between 2-6 inches and its stem stands between 3-6 inches tall. When immature, the cap is rounded and umbrella-like which flattens out as it matures. Cap color is off-white with a yellow or green tint. Underside has many thin white gills and an annulus at the top of the stem. At the base of the stem is a cup-like vulva. Spore print is white.
These highly poisonous amanita species are closely related to Amanita phalloides and also contains amatoxins. These mushrooms can be found in lawns, in grassy meadows near trees, or at the edge of woodlands. They grow either alone or in small groups. They can be mistaken for button mushrooms, horse mushrooms, meadow mushrooms, or, when immature, puffballs.
Destroying angels can have a cap that is all white or white at the edges and yellow, pinkish or tan in the center. The cap is usually 5-12cm in diameter and the stem can range from 7-20cm long. The free gills and stem are white. These species have a highly characteristic universal veil, or vulva, which forms a white cuplike structure at the base of the mushroom from which the mushroom emerged from.
Found in late winter to early spring. Commonly found in urban areas around douglas fir. This cap has caused a number of accidental human and dog poisonings over the years and is sometimes intentionally consumed for its psychoactive effects (due to ibotenic acid).
Medium-sized or larger. Light-brown to dark-brown caps with many white warts left by the universal veil and a white stem. Striations on the margin. The bulbous base has a cup-like vulva characteristic of the Amanita group.
A. muscaria has come to be one of the most well-recognized mushrooms in the world. It is commonly found in a symbiotic relationship with many trees such as pine, fir, spruce, cedar, and birch. This mushroom contains the psychoactive compound ibotenic acid. They have caused accidental poisonings in dogs and humans, but some intentionally eat it for its psychoactive effects. It is regarded as much more poisonous for dogs, who may be attracted to them based on their fishy odor. The mushroom is thought to be an essential ingredient to the “soma” brew and is used ritualistically in areas like Siberia.
Fly agarics commonly have a bright red cap 3-8in in diameter with white “polka dots”. It has a white stem with free white gills. It has striate cap margins and a ring-shaped volvas that extend partway up the stem from the bulbous base. Varieties of this species can have caps that range from white to yellows, oranges, deep reds, or brown, and a universal veil that is white or yellowish.
Also known as the False parasol, this poisonous mushroom is the most common cause of wild mushroom poisoning in North America. It is common in southern states from late summer to fall. It can be found sprouting up in lawns, oftentimes in what are called fairy rings, a naturally occurring ring of mushrooms that forms as a result of the mycelium expanding for nutrients underground.
When immature, the cap is ball-like 2-4 inches in diameter. It grows into a nearly flat cap 6-10 inches in diameter. The cap is white, fibrous, and scaly and is attached to a white stem 8-20 cm long. Gills are white and become greenish-grayish as the mushroom matures. Initially, they are covered with a partial veil that forms a ring around the upper stalk. The spore print is green.
Sometimes referred to as the autumn skullcap, this mushroom can be found in North America, Europe, Asia, and Australia. They are commonly found on rotting wood, often in clusters. They are classified as a Little Brown Mushroom (LBM), which makes them hard to identify and easily confused with some edible or psychedelic species. The deadly galerina contains liver-destroying amatoxins like the highly poisonous Amanita species.
Cap ranges from 3-6cm in diameter with edges that curve in towards the gills. The convex cap is yellow-brown to dark brown, usually sticky and smooth. The stem is usually less than 2 inches long. The spore print is rusty brown. Gills are yellowish to brownish. Often, there is a ring that disappears with age.
C. filaris is a common small, deadly lawn mushroom that grows in dung, compost, rich soil, and woodchips. Although found in Europe, Asia, and North America, C. filaris is a common lawn mushroom in the Pacific Northwest. It contains the same amatoxins found in the death cap.
The conical cap is 1-2.5cm in diameter attached to a slender stipe. The color is butterscotch-brown to tawny-brown with pale, striate margins. Rusty brown spores.
Many of the mushrooms discussed naturally grow in lawns and mulch. Since they are a vital part of the ecosystem, the only way to fully ensure they don’t pop up is to not have lawns or mulch. Mushrooms and grass often thrive under the same conditions. There are some steps you can take, however, to reduce the chance of having any mushrooms that are a nuisance in the yard.
- If the mushrooms are a pest in the lawn or garden, remove the new fruiting bodies by pulling at the base. While mushrooms fruit from the underground mycelial network, doing this just as they have sprouted can reduce the chance of them spreading new spores that can later cause new fruiting.
- Avoid overwatering the lawn. Mushrooms thrive in high humidity conditions, which is why they commonly start popping up in the lawn after heavy rains.
- Remove rotting organic matter from the front yard. Things such as dead tree roots, old mulch, compost, and leftover sawdust in the yard will encourage mushroom growth. Dead tree roots or lumber scraps are well-liked inoculation points for the mycelium.
Approximately one hundred species of mushrooms can cause a negative reaction when eaten, and a small handful is deadly. Without having an expert 100% confirm the identification, it is very hard to know for sure whether or not a mushroom in the yard is safe or poisonous. For this reason, it is always best to err on the side of caution and teach your dogs and small children to never play with or eat mushrooms that grow in the yard. The deadly mushrooms discussed above have fatal consequences even in small quantities as little as half a cap. To reduce the risk of mushroom poisoning, you can:
- Make sure they are not unsupervised in areas where these mushrooms can grow. This can be helpful in attaining peace of mind that no poisonous mushroom ingestion takes place.
- Be sure to remove all mushrooms from your yard, especially if you suspect any Amanita species are growing. These species are especially poisonous to dogs and often have a fishy odor which can attract dogs to eat them. Common symptoms of mushroom poisoning by these species include tremors, ataxia, seizures, sedation, vomiting, diarrhea, jaundice, and coma.
If you believe your small child or dog has eaten a poisonous mushroom, take note of where the mushroom was growing and try to obtain a sample of the mushroom for a positive ID. Get emergency medical attention right away.
The treatments vary depending on the time since ingestion, but normally the treatment plan involves ridding the stomach of the poisonous contents (using activated charcoal or stomach pump), using homeopathic hepatoprotective agents like an extract of milk thistle, and keeping the poisoned well-hydrated.