View Full Version : A Mushrooming Problem

05-14-2002, 09:35 AM
Hi All! I've been reading this forum for quite some time and have really enjoyed all of the great suggestions and help that is offered here.

I've got this problem I hope someone can help me with. About 3 years ago, I replaced my lawn. I tripple killed everything and then had about 15 yards of new sterilized soil brought in. Then I put in a great sprinkler system and then seeded the lawn with ninjafica (sp?). Anyway, the grass looked great and I was one happy camper.

That is, until I had these mushroom that started cropping up. I thought at first that it may have had something to do with over watering. I gauge the sprinklers run only twice a week giving me 3/4" each time for a total of 1 1/2"/week. Still, the muchrooms commeth fourth. I've even tried to stop watering all together for several weeks thinking that I can kill them with the lack of water. No such luck. As soon as I start watering again, their back in full force. It started out where they were only in about one sq. ft. of area. Now, they occupy about 5 sq. ft.

The local nursery folks can offer only one suggestion. They say that I'm overwatering. I just can swallow that. No one can suggest anything that I can apply or do to get rid of this mushrooming problem. :angry:

I'm at my ropes end and I need help. The only thing that I can think to do is to kill this entire area of the lawn and reseed it. I REALLY don't want to do this.

Any suggestions? I could post some pictures this evening if it would help.

Thanks in advance.

05-14-2002, 11:41 AM
What time do you water?

What are the temps at night?

What kind of grass?

05-14-2002, 12:40 PM
Those mushrooms probably aren't causing any real turf damage are they?

Mowing is usually all that is required to rmove mushrooms.

Some fungicides used to be labeled for control of mushrooms, but I know of none that still are. I think Mancozeb worked but don't hold me to it.

Heritage is labeled for control of Fairy Rings which "could" be part of the cause. Do to it's very unique chemistry, I'd guess that Heritage would at least supress mushrooms. I can't legally recommend it that way since it's not specifically labeled, but I know what I'd do.




05-14-2002, 05:39 PM
Mushrooms are feeding on organic matter. What type of soil did you place on your old lawn, organic soil? What type of fertilizer do you use, organic fertilizer? I get mushrooms on my lawn when weather conditions are moist and in the shade of trees. I use organic fertilizers in these areas. Where I don't use organic ferts, I don't get the mushrooms. As usual, Tremor is right. Mowing should take care of the shrooms.


05-14-2002, 07:49 PM
OK, I'll try to answer all the questions.

KIRBYSLAWN: I water usually between 4am-6am, night temps average about 42-48 degrees, Ninja Fescue (tall)

LAWNSTUDENT: I don't know. It was 3 years ago. At my age, I'm happy to remember what happened this morning.

TREMOR: Damage? Well, this stuff is spreading like a cancer.

I'm using Scotts Lawn Pro, Super Terf Builder 29-3-6

Hope I answered them all. Also, if you'd like to see what I'm talking about, check out this LINK (http://www.w5blt.com/Mushroom/Mushroom.htm). These are a little "wilted" now. When they come up, they're nice and white and about 2-3" tall. These pictures are after not mowing for about 10 days. I'm getting ready to mow tonight. If it runs true to course, I'll mow and water tomorrow morning and within 2 days, I'll have a brand new crop.

Help! :cry:

05-14-2002, 08:16 PM
1. Are they edible?
2. They are not a lawn pest so who cares.
3. Was the sterilized soil from a mushroom farm?
4. Identify this particular mushroom, learn its culture, habitat etc and then do something it doesn't like if it would not be detrimental to the lawn.

05-14-2002, 08:19 PM
OK, now I'm concerned. By the looks of the photo, it appears as if the mushrooms are in the vicinity of tree roots. If large quantities of soil were place over the tree roots three years ago, the tree roots may now be dying. The decaying roots would contain sufficient organic matter to fuel the mushroom blooms following rains or irrigation.

Might the soil have been added to cover roots? The trees could easily be outcompeteing the turf for sunlight. As shade tolerant as Tall Fescue is, the trees will win every time. Unless of course, the roots are dying from a lack of oxygen.

Some soil borne root diseases affect trees. Especially when good turf cultural practices alter the normally drier environment that some tree sppecies require.



05-14-2002, 09:43 PM
I agree with TREMOR. Mushrooms are the fruiting bodies of rotting organic matter. Old tree roots will cause this problem for many years with the right conditions. Cool, wet conditions will stimulate spore growth and mushroom production.Watering at 4-6 AM is not recommended, as it promotes the spread of every kind of fungus growth available.( Helminthosporium-leaf spot- in particular) As far as mowing them goes, I don't like that control method. When the blades hit them, they splat gooey gunk everywhere. You did not say how often you are watering. If you water every night, you need to change that. Light, frequent watering promotes fungi and can cause shallow rooting. You should have one or two deep soakings done right at sunrise to get the best results. Let there be wet & drying cycles to moderate the process. Good luck.

05-14-2002, 10:51 PM
MATTHEW: I've added a couple of pictures to that web page. It shows the tree a little better. I think that it's called a "silk tree". But, I'm not sure. I usually water 2 times a week. I've got it gauged to water 3/4" each time for a total of 1 1/2"/week.

The roots are fully covered and the mower does not come in contact with them. When I originally put the top soil on, I tried to take paticular care not to add too much to the top around the trees. Maybe 1-2" at best. However, no roots were ever showing. I'm just about to the point of watering only once per week. But, I think that the lawn in the heat of summer will dry it out too much.

You guys (or gals) have got me worried now about the root rot stuff. How would I know for sure if this is the case? BTW: I live in N. CA near SF if that gives you an idea of the thermal region.

05-14-2002, 11:02 PM
My Grandfather lived for a number of years in Concord, CA!
Now about the shrooms - has anyone mentioned Fairy Ring? It is a basidiomycete that basically eats and releases nitrogen. Is ther a green ring around it?
Anyway - another tip would be to take a tine fork and areate around the mushroom circle.
If it is fairy ring - let me know there are a few things you can do

05-14-2002, 11:07 PM
I'd be surprised if it is from root rot. I get these as well under my trees. Your watering twice a week and this leaves the area moist most of the time because the tree shades this area from direct sunlight. I'll bet you muclh your cliping too. High organic content in the soil. Scotts is not organic, not your problem. You might check your thatch layer in this area. Is it greater than 3/4 inch? You should cut your fert app in half under a tree. Fungus could be feeding on decompoing thatch layer. And overwatering is a contributing factor to excessive thatch build-up. What about the leaves in fall. Do you mulch those into the lawn also? More organic matter to feed those shrooms. Rake your leaves up from under this tree next fall. Good luck.


05-14-2002, 11:32 PM
Fairy Ring? No, I don't think so. Then again, I'm not exactly sure what they are.

As for mulching, no soap here either. I bag and remove all clippings. I mow at appx. 3" consistantly.

05-15-2002, 07:09 AM
Fairy Rings: Aerate & Heritage. Look for the dark green circle with the shroom's growing within the darker area or very close to it.

Root Rot: Consult a certified arborist or "carefully" begin some shallow excavation to examine the roots being careful to not cause injury in doing so. Is there any crown dieback in the trees? If so, get an arborist quick regardless of whether you want to hear what he/she has to say. Look for state & trade certification(s) or don't bother.

Turf damage: Probably thinning from shade. Tall Fescue is not a notorious thatch builder, especially in the shade. The canopy would limit air & sunlight. Which also means that mushrooms would be happier than the turf. The mushroons CAN'T cause any damage to the turf (unless they're utterly huge). The 'shrooms are indicative of the conditions causing the turf to thin. In other words, they're a symptom, not a cause.


05-16-2002, 10:20 PM
Soil types will affect total moisture. Sandy and loam soils will let water leach down. Clay soils will hold water for a long time. You can check the soil moisture levels by using a core extractor. Push it down about 10" and see where the moisture ends. Do it the same day you water and the day before you water. If it is consistently wet down to the root zone each time you test, you just have too much water. If you want to do a simple test for what type of soil you have, take a pinch of it and wet it. Then, rub it between your fingers. If it feels gritty-there is sand. If it feels slippery, its got clay in it. If it breaks apart easily (and is not too gritty) it is a loam soil. Good luck.

05-16-2002, 11:16 PM
Mushrooms! Nothing more than an aesthetic problem. But I have a question for you. How do you triple kill something? Dead is Dead, how does something die more than once. Don't forget READ the LABEL. Apply correctly or you will triple kill our industry..

05-16-2002, 11:42 PM
As far as triple kill, I think you're refering to when I put in my lawn initially. I would treat the entire lawn with grass killer and wait a week. Till it up, water it and see if anything grows (which it did. nothing is 100%). I treated it again, waited another week, watered and waited to see if anything grew. Some small spots of grass still sneaked through. So, a last application was necessary.

As for mushrooms being an aesthetic problem, well, maybe you're right. But, the fact remains that they look ugly and I just don't want them there.

05-17-2002, 02:02 AM
Bob, look at this from a simple standpoint. Mushrooms are a fungus. Mushroom fungi generally grow on dead organic matter, especially dead woody materials. Since you show them around the base of your tree, and assuming the tree is showing no stress itself, these may be from dead roots. You can often see the pattern of roots in the mushroom pattern. Trees often grow new roots from the base, and some of these roots die off regularly.

Overfertilization will enhance mushroom growth, especially on buried dead woody material!!! Make sure you are not exceeding your state extension recommendations in that area. You may want to reduce rate of fertilization in the problem area.

Most mushrooms like it dark and damp. Under the tree stays darker and damper than the open areas of your lawn. Try this next time you water; cover a good sized area (at least 5' by 5' up to 10'x10') in the problem part of the lawn with a tarp, to keep this area from getting water. Then see if mushroom growth does not appear in that area, but does appear in irrigated areas. Only then will you know for sure that your irrigation is enhancing the mushroom growth. If that is the case, then you need to micromanage water application in that problem area. Apply just enough water to maintain lawn, and not benefit mushrooms. Would be a trial and error project.

Your 4am to 6am watering is ideal, not much darkness left to enhance fungus growth. But you could reduce amount of water to 1/2" each irrigation. General rule is 1" of water per week, higher in hot weather. Don't worry about fairy ring, they are distinctive circular patterns of dead grass, with mushrooms growing around the circle; that's not what your pics show.

And be delighted that you don't have an old stump underground, to grow the 1' to 2' diameter mushrooms hard as wood; actually need an axe to remove them. LOL.