Skip to Content

Growing Corn? If You’re Lucky, It Will Catch This Disease

Photo of a corn plant infected with smut, red arrows pointing to galls

When you’re growing vegetables, you rarely want your plants to get sick. We put a lot of work into making sure they don’t. So, it’s usually an upsetting surprise to find that something you are growing has picked up a disease.

Well, except when you’re growing corn. There’s one plant pathogen you might want to come your way.

A Shocking Surprise

When you think of the perfect summer produce, what comes to mind? Is it slicing into a beautiful heirloom tomato, eating yet another slice of deep red watermelon? For myself and many others, it’s an ear of corn dripping with butter, salt and pepper.

Clearly, then, it’s a bit shocking when you head to the garden to pick sweet corn for dinner and notice an ear that’s abnormally fat, almost bursting out of the husk. Pulling back the husk reveals a grayish mass of lumpy “things” growing where your perfect rows of yellow kernels should be.

hand holding a corn plant infected with smut

This discovery is usually met with a visceral shudder and a, “What in the expletive deleted is that?”

All thoughts of perfectly buttered sweet corn evaporate as you try to figure out what this alien thing is.

Corn Smut – One Man’s Trash is Another Man’s Truffle

What you’re holding in your hand (if you haven’t flung it to the far-reaching corners of your garden out of disgust) is an ear of corn infected with the pathogenic fungus Ustilago maydis.

A cluster of corn smut galls
I thought we planted corn, not mushrooms.

The spores spread on the wind or when water carrying spores is splashed on the corn. The spores enter the corn through wounds caused by insect damage or via the silk at the top of the ear. Once inside, they act like a cancer, causing rapid cell growth within the plant. Galls form, eventually filling with spores before they burst, releasing the spores into the air to infect more plants or to winter over in the soil and do it all over again next year.

The galls can show up anywhere on the plant, the stalk, the leaves, etc.; however, it’s most common for them to appear on the ear of corn itself.

corn smut growing on the stalk of a corn plant
Here the galls have erupted from the stem of the corn.

In the end, it’s probably not what you were hoping for when you planted corn earlier in the season.

Of course, if you’re one of a growing number of gardeners, your reaction to this discovery is going to be very different. You may jump up and down with glee and yell, “Honey, put the hamburgers in the freezer. We’re having huitlacoche tacos tonight!”

Huitlacoche tacos
Hmm, hold the cheddar and add cotija and this is a perfect taco.

That’s because you know you’ve hit the jackpot, and the winds have blessed you with a culinary delicacy – Mexican truffles.

Huitlacoche
Huitlacoche can have a somewhat blue-gray hue.

Corn smut, or huitlacoche (pronounced weet-luh-ko-chay), has long been a staple in Mexico, where it’s harvested and used as a non-meat protein in many dishes. You can even find canned huitlacoche in a well-stocked Latin goods store. But like most things, fresh is best.

When to Pick Corn Smut to Eat

Look for ears with growth within the first couple of weeks of development. The galls should be a soft gray or blue in color and firm with a slight give. (Think of the perfect plum.) It should still have the shape of an enlarged kernel of corn.

Huitlacoche

If you pick them when they’re too small and hard, they will be bitter. You don’t want to use any of the mushrooms that have burst or have spores inside them when you open them, and you should avoid those that have gone soft. You shouldn’t be able to tear the skin by rubbing it. If you can, it’s too far gone.

Corn smut, some galls have burst open
You can see here that some of the galls have already burst, while others are still edible.

What Does Huitlacoche Taste Like?

Huitlacoche is soft and slightly chewy, like most mushrooms. It has an earthy-mushroom flavor, but it’s slightly sweeter, bringing in the flavor of the corn it’s growing on.

As far as mushrooms go, they have a strong flavor, much like black truffle, that can easily overpower a dish. So, it’s best to mix it with other ingredients where it can really shine.

Gourmet huitlacoche dish
Aztec caviar, anyone?

Here are a couple of recipes to get you started:

As always, Alan at Forager Chef has a simple recipe that puts the focus on the star ingredient.

Traditional Mexican Huitlacoche Quesadilla

Growing Up Bilingual offers a savory soup.

Cream of Huitlacoche Soup

And Mely of Mexico in My Kitchen serves up a traditional huitlacoche taco with an interesting side of the history of huitlacoche in Mexico.

Huitlacoche Tacos

If you end up with corn smut in your garden, will you be eager to try it? As a forager and mushroom fan, I have to say I’ve had my fingers crossed for a couple of years, hoping to try it.

For those eager to give this tasty delicacy a try, put the word out that you’re looking for it, and I’ll bet someone will have it in their garden or farm.

Okay, That’s Great and All, Tracey, But I’d Rather Have Sweet Corn

I get it. You started the growing season hoping to get corn, not mushrooms. But before you pitch those wonky ears of corn, ask around. You’ll likely find someone who will happily take it off your hands. If you have any good local Mexican restaurants nearby, they may even be willing to buy them from you.

If you want to avoid the same issue next season, it’s important to remove any infected plants before the galls burst. Otherwise, the cycle will continue again next year. You can also choose to grow sweet corn varieties that are resistant to smut.

Tilling will only drive the remaining spores deeper into the soil, where they will winter over, so you’ll want to skip tilling this year. You might want to skip it altogether and go no-dig to improve the overall health of your soil anyway.

The best way for a home gardener to deal with corn smut is to pull up the corn as soon as you notice the fungus and dispose of it properly by burning it or putting it in your refuse. You don’t want to compost it. You’ll need to plant corn as far away from that spot as you can in subsequent seasons.


Get the famous Rural Sprout newsletter delivered to your inbox.

Including Sunday musings from our editor, Tracey, as well as “What’s Up Wednesday” our roundup of what’s in season and new article updates and alerts.

We respect your email privacy


Tracey Besemer

Hey there, my name is Tracey. I’m the editor-in-chief here at Rural Sprout.

Many of our readers already know me from our popular Sunday newsletters. (You are signed up for our newsletters, right?) Each Sunday, I send a friendly missive from my neck of the woods in Pennsylvania. It’s a bit like sitting on the front porch with a friend, discussing our gardens over a cup of tea.

Originally from upstate NY, I’m now an honorary Pennsylvanian, having lived here for the past 18 years.

I grew up spending weekends on my dad’s off-the-grid homestead, where I spent much of my childhood roaming the woods and getting my hands dirty.

I learned how to do things most little kids haven’t done in over a century.

Whether it was pressing apples in the fall for homemade cider, trudging through the early spring snows of upstate NY to tap trees for maple syrup, or canning everything that grew in the garden in the summer - there were always new adventures with each season.

As an adult, I continue to draw on the skills I learned as a kid. I love my Wi-Fi and knowing pizza is only a phone call away. And I’m okay with never revisiting the adventure that is using an outhouse in the middle of January.

These days, I tend to be almost a homesteader.

I take an eclectic approach to homesteading, utilizing modern convenience where I want and choosing the rustic ways of my childhood as they suit me.

I’m a firm believer in self-sufficiency, no matter where you live, and the power and pride that comes from doing something for yourself.

I’ve always had a garden, even when the only space available was the roof of my apartment building. I’ve been knitting since age seven, and I spin and dye my own wool as well. If you can ferment it, it’s probably in my pantry or on my kitchen counter. And I can’t go more than a few days without a trip into the woods looking for mushrooms, edible plants, or the sound of the wind in the trees.

You can follow my personal (crazy) homesteading adventures on Almost a Homesteader and Instagram as @aahomesteader.

Peace, love, and dirt under your nails,

Tracey
[simple-author-box]