Question
We have a sod lawn which is only 3 years old.  Last fall our lawn maintenance service recommended for it to be aerated, which we did do.  This year however, we have a growing problem.  Something is taking over our lawn very quickly.  The spots are almost like the Target logo and about the size of a frisbee.  Nearly round dead spots in the grass with a tuft of grass in the middle of the circle.  The lawn service took a sample of it and cannot determine what it is even though we are paying them 500/year to control weeds and pests.  Anything you can recommend would be greatly appreciated.  I used to call our lawn "carpet" becuase it was that nice, but now it looks like a ratty old worn out carpet.  Thank you in advance Taryn in Jackson, Michigan  P.S. I can send picutres to help show the situation.  

Answer
Hi Taryn in Michigan!

Any chance you know what kind of Sod Lawn you bought 3 years ago?  Fescue?  Bluegrass?  Rye?  Anything here sound familiar?  Any way you can get your landscaper to i.d. the grass you are trying to save? You paid for it, you deserve to know. Tell them your "consultant" told you they have that information. Tell them your mother demands it.  Maybe it's a blend.  Find out.  If nothing else, to re-seed the brown patches, you want to use the same grass.  All grass seed has a name.

We do not need photos of your lawn.  My crystal ball says that's a Fungus amongus.

Which one?  Just for fun, pull up the North Dakota State Extension Service  (www.ext.nodak.edu/extpubs/plantsci/landscap/pp950w.htm) and see if Fairy Ring looks familiar.  More on that later.

You don't really need to know.  It's there and you have to get rid of it.  We can study it and analyze it, but if you don't get rid of it, who cares what it's called?

It's the first of many probably because once you disrupt the balance of Nature, which your lawn service has done so efficiently with their use of pesticides and herbicides and probably next fungicides, you open a door for all things Fungal to live at your place.

If you took a soil sample from every yard in the country, they would all have LOTS of Fungus.

Yet, only SOME of them would have a Fungus Disease.

Why?

I mean, how can it be that a beautiful, smooth, crystal-green lawn can suddenly erupt with all those Fungus pimples?  You feed it, you water it, and the one that gets all the attention gets sick and the one that is neglected is just... ugly?  And they both test for the same Fungus?

Life is not fair.  But there is a scientific reason for this.

Fungus needs MOISTURE to launch an attack on a lawn anywhere on earth.

The scary thing is, these pathogens are already in your soil, all the time, waiting for just the right time to invade.

Most of these Fungi need serious moisture.  Otherwise, they are helpless.  So you have to really accommodate the
Fungi Kingdom or they simply won't give you the time of day.  In fact, after you read about them, you have to wonder how people ever manage to get Fungus growing in their lawns.

Let me guess... You have an automatic sprinkler?

The cool August nights are descending on Michigan... and your sprinkler is spouting cool water just like Old Faithful, same time, same place, like clockwork every night in the dark on your 3 year old sod.

To quote the Colorado State Cooperative Extension Service: "With fungal diseases, moisture on the foliage determines the production of spores and their survival. Gross et al., report the severity of brown patch (Rhizoctonia solani) increases as the length of leaf wetness increases above 9 hours. The longer the leaf surface is wet, the greater the risk of infection and the greater the number of infections per leaf."

In other words, they are saying that study after study proves that Fungi cannot attack dry grass.

There's more.

"Fidanza et al. report minimal infection of this disease occurs when the duration of leaf wetness is below 6 hours with severe infections occuring when the length of leaf wetness increases to 8 to 10 hours. Irrigation in the afternoon is directly associated with an increase in infection, especially when warm day temperatures are followed by cool night temperatures (Dickson. 1930). Once the optimum temperature is reached gray leaf spot of perennial ryegrass and tall fescue (Festuca arundinacea Shrebl) caused by Pyricularia grisea (Cooke) Sacc. increases in severity with an increase in the length of leaf wetness (Uddin et al. 1997; Moss & Trevathan, 1987; Williams et al, 2001)."

Taryn, I have to say, it does sound to me like you are putting the red carpet out for the neighborhood Fungus.  

If you want to stop them you had better do a 360 degree turn and keep that grass nice and dry.  Water when you need it.  Right now, you don't need it.  Turn off the autosprinkler.

Because you have set the perfect stage for a Fungus Farm.  Cold air - Moisture - Darkness - and NO NATURAL PREDATORS.

The trouble began last year when the Lawn Service decided to aerate.  Healthy soil does not need to be aerated.  It's got plenty of air, because it isn't compacted, because it has plenty of organic matter, and because it has a good Nitrogen cycle working underfoot.

Was your landscaper was trying to address a thatch problem?

Some people blame everything on thatch.  You may have already heard someone do that.  Yet, thatch is never a problem when sensible gardening routines are practiced.  "Sensible" means not trying to "purify" your lawn by eliminating microbes and beneficial Fungi (yes there is such a thing as BENEFICIAL Fungi) and bird food.  Like I told someone else, a healthy lawn hums like a well-oiled machine.

Bottom line: Microbes -- not powdered Fungus killers in plastic bags made by Scotts -- will be your best weapon in the war being waged on your front lawn.

I hope you like vegetables.

By the way, some of the most cutting edge research on these subjects are done in The Netherlands because there it is ILLEGAL to mix regular kitchen garbage with ordinary trash.  All kitchen garbage is trucked to a compost center and used for Agriculture.  It's the law.

Of course, It doesn't hurt to check for other possible causes of these Frisbee rings.  

Do you have maybe Grubs?  I think your Lawn Care Pros have already sprayed for that, but you can check.  Grubs are fingernail-sized curled beetle larvae.  They live under the soil, under your grass, and eat your roots.  

In a healthy yard, there are grubs.  Not a lot; just enough.  Birds eat them like caviar, by the ton.  

But when Nature gets off balance, and too many beetle larvae are eating the grass roots, you begin to notice oddly shaped brown patches in the grass, especially in late summer.

And because the grass roots have already been eaten, the dead patches can be pulled up very easily. Yank a patch of dead grass and dig a little with a hand fork into the soil.  

Remember, this only happens when Nature gets off balance.  Because there are lots of natural controls out there in your garden soil to keep grubs from being too comfortable.  If you see more than one or two grubs per square foot, go out and pick up some Milky Spore Disease at Home Depot, and sprinkle on generously, then water and wait.  It also helps to have birds and squirrels on your side.  If you stop using pesticides, you will increase those healthy bird and squirrel populations.

Alas, I do not think grubs are your problem.

Chinch bugs? These tiny gray-black bugs suck plant juices right out of your grass.

Symptoms are brown-yellow patches, especially when the weather has been very hot and dry.  You can check for these with an empty can, both ends removed.  Just sink it into the ground at the edge of one of those Frisbee circles and fill the can with water.  

If there are Chinch Bugs down there, they will unattach themselves from the grass and float to the surface gasping for air.  You'll see them in the can.

Alas, it does not sound like this is going to be your problem.  I do think you have Fungus.

What are we going to do about this, Taryn?

First, watch your lawn care professionals carefully and tell them you do not want any more stuff on your lawn.  The only stuff they have is going to damage it further.  Unless it's humus, compost or corn gluten - I'll bet they don't even know how to spell humus - they should go away and leave your lawn alone.  And do not pay them for that "test".  Any Cooperative Extension Service can give you an answer for this in a heartbeat.  I don't know why they cannot do that.  It's not very professional.

If you have looked at those Fairy Ring symptoms above and declared "BINGO!", go ahead and read some more about this darling little disease at the Colorado State Cooperative Ext Service where one intern has written an essay on the topic (www.coopext.colostate.edu/chaffee/fairyring.html).  Ignore the advice about Roundup, which is just going to make your lawn more miserable and prolong the pain within the soil structure and microbes desperate for a little kindness.

Perhaps you have Necrotic Ring Spot (www.uoguelph.ca/~thsiang/turf/nrsrule2.jpg).  Symptoms show up in early spring, subside during the heat of summer, then in late summer/early fall they return but worse.  This fungus (and others) can travel from house to house as the landscaper takes his spore-contaminated lawnmowers to each account during the day.  

Excess thatch and/or fertilizing contribute to NRS; low soil pH (acidic) and/or stress to grass caused by low mowing heights aggravate the problem by reducing resistance.  

If you think your lawn looks like it's suffering from NRS, tell your landscaper to stop fertilizing the grass - it does not need Nitrogen anyway during the height of summer heat, when most cool season grass should be fading into semidormancy.

There are steps you would be able to take to target your lawn disease - if you had not already saturated the soil with chemicals that will neutralize anything you put in there.  A bag of "fungicide" may or may not address any Fungus problem you are facing.  If this were my lawn, I'll tell you what I would do.  I would put the landscaper on a Mow-Only contract and tell him not to do anything but mow my lawn and, next month when the Fungus has subsided (because I am no longer watering my grass in the dark every single night) re-seed the dead patches.  And I would find an organic lawn care organization in my area to take over this problem.  They will grow beautiful grass that will not get anyone sick; you'll be able to walk across it in the morning on your way to work, and you won't track pesticide residues into your house when you come home.  You'll be able to breathe the air around your house without toxic fumes.  Best of all, your grass will be green, lush, and problem free, which is really the way God planned it.

Sorry this turned into the Book of the Month.  I do get carried away sometimes. This is a very simple solution. I believe it will probably work on any Fungus attacking your lawn.  Thank you for writing.  Please keep in touch and let me know how things are going... even if you disagree!  And if you are able to resist putting more toxic waste on your lawn, write me next month and we'll discuss your plan of action.  Remember: Healthy grass never gets sick.