Giant Puffball (Calvatia gigantea)
Giant Puffball illustration by "Wildman"

Giant Puffball

watercolor painting


The giant puffball is a whitish, Styrofoam-like globe as small as a softball or as large as a beach ball, with short, root-like mycelial (fungal) fibers connecting it to the ground.

Giant Puffball

Giant Puffball

Note the white interior showing between the cracks. This is when you should cook this mushroom.

It's white, soft and undifferentiated inside at first, like other puffballs, then sickly green-brown.

Giant Puffball, Aging

Giant Puffball, old specimen

The green interior is on its way to becoming trillions of spores.

Finally maturing, trillions of microscopic spores emerge as a puff of dark brown powder when kids kick the mushroom.
Giant Puffball and Samantha Brandt

Giant Puffball and Samantha Brandt

photo by Joe Brandt

A similar, equally-huge western giant puffball (Calvatia booniana), covered with spectacular polygonal white to buff warts, grows in semi-arid and sagebrush areas in South Idaho, adjacent states, and the Cascade mountains, from June to August. It's also a choice edible, as is the sculptured giant puffball, (C.subsculpta) which is even more warty, and has a sterile base.
Western Giant Puffball

Sculptured Giant Puffball

photo by Eric Nyberg

Caution: Beware the false giant puffball, a.k.a. the poison goalpost fungus, common in grassy fields throughout much of the Earth.

Poison Goalpost Fungus

False Giant Puffball
(Poison Goalpost Fungus)

Note the cracked surface about to erupt, ejecting enough spores to victimize up to 22 people at once!

This mushroom is so deadly, merely inhaling the spores rearranges your brain's neural synapses, making you race endlessly back and forth across a field, stopping occasionally to jump up and down and cheer or curse insanely, never resting until death from exhaustion ensues. Poisoning is so virulent, relatives of the victim, especially the parents, have been known to succumb as well!
Soccer Players

Victims of the false giant puffball in the throes of madness.

Except for this species, the large puffballs have no poisonous look-alikes, so they're fair game for beginners.


Look for giant puffballs on the ground in well-fertilized fields or pastures where the underlying fungus has plenty of underground manure to decompose.

Giant puffballs also grow on the sloping areas of bare earth in urban areas, places where people tend to discard litter. Here the puffballs hide, disguised as Styrofoam.

I once led a tour that first met at the base of a wooded hillside in Queens, NY. We piled into cars to carpool to the park's interior. I got in last, to make sure no one was left behind. Just as I was about to close the door, I noticed that the entire hillside where we had been sitting for 20 minutes was covered with giant puffballs, which I announced at the top of my voice.

Everyone raced to the hillside, and there were enough enormous giant puffballs for everyone to get one, except for me. But after the tour, I raced home on my bicycle, dumped all my gear, and continued in the opposite direction to a park where I'd found a large number of rotting giant puffballs the year before. This time, in failing light, I got them all, filling up shopping bags, backpack, carrier rack, and panniers.

Season and Range

Look for giant puffballs from late summer through mid-fall anywhere in North America.


This mushroom is a choice edible. Trim away the cuticle (covering) if it's encrusted with dirt, and cut out any bad parts with a paring knife. Try not to wash this mushroom under water, or it will become too soggy to sauté.

Slice the puffball, sauté it, steam it, or simmer it in soups, like other mushrooms. It's also great baked or grilled. It has a rich, earthy flavor with a texture of marshmallows.

This mushroom doesn't dehydrate well. To store it long-range, cook it and freeze it.