Pest of the Week
Even if you don’t know much about mushrooms, you can identify a shelf mushroom: it’s the wide, flat fungus growing out of a tree trunk. The mushrooms can be brown, gray, green, white, or even orange. Shelf mushrooms do good by aiding in the decomposition of wood. It is said that if there were no fungi of this type, there would be no forests at all, because the forests would become choked with branches and stumps that didn’t decompose. These mushrooms are also diagnostic—they signal that a tree has internal rot.
If shelf mushrooms have appeared on the trunk of your tree—often at the base of the tree or on the root flare—it’s a sign that your tree is rotting inside. Unfortunately, by the time the shelf mushrooms appear, the rot is quite advanced, and there’s nothing you can do about it. That said, some trees will stand for years even though they are suffering from heart rot, root rot, or butt rot. There’s no way to predict when the tree will fall, but you can be sure that it is losing strength.
Removing the mushrooms won’t make the rot go away. The best strategy is to keep your tree healthy so that rot doesn’t begin. The pathogens that cause rot in trees enter through wounds in the bark. In a garden, injuries are commonly caused by weed trimmers and lawnmowers. But animals, insects, wind, and lightning can also cause damage that opens a path for infection. A circle of mulch around your tree will keep the lawnmower at a safe distance. Try not to dig near your tree. Most of a tree’s roots are in the upper 18 inches of soil, so they are easily damaged. Pruning small limbs is safer than pruning large ones, as the injury will heal faster.
—photo courtesy of the Kemper Center for Home Gardening at the Missouri Botanical Garden.
Monday, September 27, 2010 7:36 PM
I found this article very interesting thank you so much !!!
Tuesday, September 28, 2010 9:27 AM
what great story I learned somthing from it I am also watching a tree that has Shelf Mushrooms growing from it
Wednesday, September 29, 2010 8:10 AM
This article hit home for me. I have an old log in my atrium that I put there for "decoration". It started growing these mushrooms. It's so interesting to watch the mushrooms grow. Thanks for the info.
Thursday, September 30, 2010 7:31 PM
I don't agree that this mushroom is a pest. As stated it is a diagnostic indicator that something is wrong with the tree. The mushrooms don't cause the problem with the tree, only lets you know there is one.
These mushrooms are edible and I don't believe they should be classified as a pest.
Friday, October 01, 2010 10:46 AM
This is timely for me as a Red Cedar on my land is showing these mushrooms on its trunk. This tree if it falls chould block a county road in front of my house, will have to see the county can take it down before winter or if I will have to remove it myself. It could take out power and telephone lines. The field across from me has a drying soy bean crop so I do not want to have this tree take out the power lines.
Sunday, October 03, 2010 6:29 PM
i was very interested in the tid-bit on the shelf mushroom. there was a giant oak cut down from center of lawn, stump also removed. so far i have had 6 different types of mushrooms growing not just close to site of removal, but throut the yard.i can not find out how to destroy them from my lawn. i go mushroom digging every day collecting half a plastic grocery bag of these 'PESTS'. does anyone have a clue how to rid them from my yard?
Tuesday, October 05, 2010 2:30 AM
I have been a "tree hugger" for a long time. I am 40 years old and just now realized that a tree can have an infection. DURH! Where have I been?
Tuesday, October 05, 2010 3:05 PM
I have a log used to "outline" or be the edge of a planter> we had a lot of rain this summer. Now there are shelf mushrooms growing on it!
Tuesday, February 05, 2013 7:54 PM
I never knew this and I always thought that a mushroom growing on a tree looks nice, but I felt that the mushroom is like a leach sucking the trees nutrient supply up. This makes more sense why they would be growing on the tree. I also thought that a mushroom growing on a tree is similar, like mistletoe. Thank you for this valuable information. This is very good to know especially if the tree is next to a house, or other out door structure. This could save someone a lot of money in damage, if the tree were to fall on something or someone! Thank You Again!
Saturday, April 13, 2013 11:50 AM
I'm kind of glad to learn this! I bought a house that had a large tree cut down in the small back yard some years before I moved in. The stump left behind is extremely large (been trying to figure the fastest, cheapest way to get rid of it!) and last summer, it was growing a few shelf mushrooms at the base. Letting it rot means I don't have to take down my fence and get my neighbor's permission to bring in heavy machinery through their yard!
Thursday, May 30, 2013 8:17 AM
i am now reading all these comments. A few years ago My daughter and I went to a FAIR s on mushrooms. Very interesting and good to taste. Commenting on "rvience" of October 4,2010.. Growth on Oak Stumps pay very well.. the members of this Mushroom Fair said some LARGE OAK SHELVES HAVE BROUGHT IN FROM $150 TO $250 DOLLARS FROM restaurants