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Too much dead grass

Posted by DanielWells 4 (My Page) on
Sat, Apr 28, 12 at 22:16

Ever since we have moved into this home, I have been trying to get my lawn re-trained. It looked fine under the previous owner (at least it to few times I saw it), but he was watering pretty much every day (about an hour per zone). I think, for the most part, my lawn is doing great. I have it back to about 3 times a week in the heat of summer and about once a week during spring and fall.

But that is not what my question is about. Every spring it seems to take much longer for me to get my lawn to snap back from winter that the rest of my neighbors. My lawn seems to 'die' every winter and then it takes a while for new growth to 'hide' the dead lawn. This doesn't seem normal to me. In the spring (and the last mowing of the fall), I have ended up having to mow way short so that the new grass in the spring can more easily hide all the dead blades. After a month or so of watering and several mowings it starts to look great again (although if you spread the blades you can still see a lot of the old dead grass in many areas). It's not thatch. Also when I rake, the old grass comes up pretty easily (and lots of it). In fact if I had the time (or energy) raking my entire lawn in the spring and pulling up all the dead grass seems to help it green up a little quicker. But I would rather solve the problem instead of treat symptoms. I have a few new ideas for this year but wanted to get some other opinions as well.

Any ideas of what I might be doing wrong? Or is this normal for some types of lawns and I just happened to get that type of lawn while my neighbors didn't? Thanks for your help.

A few other notes: I started mulching instead of bagging about two years ago. I probably didn't fertilize enough the first few years but have been pretty good the last two or three.






Follow-Up Postings:

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RE: Too much dead grass

Looks scalped. Mow higher.


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RE: Too much dead grass

These pictures are with the mower set to just under 2 inches. Like I mentioned, this first mowing I do it just a little shorter than I normally mow in order to get the dead blades to be shorter than the new blades.

These photos were a week ago and I mowed again today (with the mower set to about 2 1/4) and it is already starting to look much better. But like I said, there is still a lot of dead blades mixed in (they are just getting harder to see now).


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RE: Too much dead grass

Reyesuela's advice to you is very right. I second it. You can scalp warm-season grasses once early in the season, like zoysia, but you don't want to scalp your cool season grass. You want to get cool season grasses tall as quickly as possible in late winter going into spring, so they're able to shade out weeds with their height.

Some folks do cut cool season grasses a little lower than usual in preparation for winter, say at 2 to 2.5 inches, but coming out of winter, you want to get the grass tall again fast. It's the opposite for warm season grasses like zoysia. Zoysia is often mowed a little higher than usual in preparation for winter (not lower like the cool season grasses). Some folks will mow their zoysia a half-inch to an inch higher in preparation for winter dormancy.

In accordance with what Reyesuela said to you, you probably should be mowing your cool season grass at a height between 3 and 4 inches. I mow my bluegrass and fescue at 3.2 inches and my zoysia at either 2.0 or 2.25 inches, depending (I can't really mow the zoysia lower because of an uneven yard).

Don't cut off more than a third of the blade at a time, or you'll stunt the roots. If more than a third of the blade is cut, the grass will devote all its energy to reproducing the shoot, at the expense of the roots. The shoot is that portion of the grass that is above the soil (the blade, the stem, etc.).

So if you want to mow your cool season lawn at a height of 3 inches, wait until it reaches 4.5 inches, then cut a third off (1.5 inches).

In a case where someone waited way too long to cut his grass, so it's now gotten very high, and he needs to cut off more than a third to get it to a good height, cut off just a third, then wait 3 or 4 days, and cut off another third.


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RE: Too much dead grass

Where do you live? Zone 4 cuts across lots of climates and soils.

Your grass looks and sounds like Kentucky bluegrass, so I'll make that assumption.

Have you ever had a professional soil test done? If not then I would recommend sending one to Logan Labs in Ohio. Then come here or to another forum to get help with the lab test results. What you are asking is to take your lawn to a higher than average level. To do that you'll need a test to fine tune the levels of micronutrients in your soil. This goes beyond N, P, K, and pH.

Can you be more specific about the fertilizer you have used, the amount, and when you applied? Your fall app will make or break your spring green up. But that works best when the soil is right, so if you are really serious about this, get that Logan Labs test. Don't rely on your local agriculture extension agency. I'm sure they are kind people who's hearts are in the right place, but soil testing is a sideline for them. LL is a professional lab. $20 is about the same price as a county agent would charge. If you asked the county agent for a test identical to the LL test it would cost you an extra $50 because it is not their "normal" test. They have to order the test materials and learn how to use them. Logan Labs does the better test all the time so they stock the chems in bulk and are well versed in how to use them.

Have you used any herbicide or insecticide or fungicide in the past year? If so, what did you use and when?

You are watering too frequently. In the cool months you should be watering monthly, not weekly. In the summer it should be weekly not semi-daily. Water about an inch per week all at once. You'll have to measure your sprinkler output with tuna or cat food cans to determine how long it takes to get a full inch.


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RE: Too much dead grass

Wow, thanks for all the great responses. First off, I am in Utah near Salt Lake City (just south).

Regarding the length. My cutting it shorter in the fall was kind of a backlash to trying to solve the issue I am asking about. I used to leave it much longer (in the 3" to 4") but the amount of dead material I had to clear out every spring was crazy. The past few years I have tried the shorter blades and I have had much less dead material to worry about and I seem to be able to green up the lawn just as quickly as before (just not as quickly as my neighbors and they don;t seem to have all the dead material). It sounds like cutting it short in the fall may be OK. But I need to immediately go back to the 3" to 4" for the first spring mowing. The reason I tried cutting it so short this spring was because it seems to be getting rid (or mulching) a lot of the dead material. Maybe that was misguided. But if I can get rid of the dead material in the spring, I will also remove my need to cut it short in the fall.

Regarding the fertilizing and other chemicals: I wish I had more detail for you. Fertilizing has probably been the thing I have been the most lax about. I have pretty much been buying just seems good at the time. I have mostly been using an IFA mix recently for Lawn and Gardens. I have on occasion used fertilizer that has contained pest control and/or insect control (but I can't remember the specific brands). I use a drop feeder and follow the instructions on the bag for the amount. I most often just spot treat the weeds in the lawn with a hand sprayer and a lawn safe weed killer (I have used several brands). But on a few occasions I have purchased the hose attached variety of pest and weed control solutions. And I have never used a fungicide. This year I gave in and just bought the Scotts four step program to see if I could learn something from them. That's my current plan anyway.

Watering wise, the front is on a slope and it seems that if I don't water often, once the heat of summer sets in, I start to get dead spots (we do get temps above 100 often). I have been working diligently over the past few years to make the roots go deep (remember the daily watering of the previous owner). When I need to cut out sections to replace sprinklers and such, the roots do seem to be very deep now. Parts of the backyard (more even, not sloped) do get a lot less water and do fine. I try to do deep soaks less often (I heard a trick once that I should run my zones shorter but run the zone cycles back to back giving it time to soak in after the first run). The standard watering for the neighborhoods (and what the city asks us to limit to) is three days a week. We have pressurization irrigation that is relatively cheap so it seems that most opt for the easier option of watering as often as they can. I have tried to stay well under that when I can. It sounds like I could be even better.

Soil quality: I have never had my soil professionally tested. All the nurseries say that we have very alkaline soil that is high in phosphorus. I bought an over the counter soil testing kit this year and tested the soil in my garden. I verified that wisdom: high alkalinity, high phosphorus, high potassium and nitrogen deficient. I did have someone ask me recently if I ever added iron. I have never intentionally added additional iron. It is possible that some of the commercial fertilizers I have used has contained iron (I know one of the steps of the Scotts contains iron). Maybe that's what it needs (or at least in part). I will have to look into the Logan Labs option. Their test looks very complete.

Wow, so there it is all out in the open (with some potential over-explaining). Thanks for all the ideas so far. I appreciate you all taking the time to help us less knowledgeable guys out.


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RE: Too much dead grass

Wow, even with all that text I wrote above I realized I didn't answer the question about fertilizer frequency. Like I said, I haven't been great. For the first few years if I fertilized twice I was doing good. The last few years I have fertilized three times a year (spring, summer, fall).


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RE: Too much dead grass

Take a look at the other forum topics where tiemco replies to soil test results from Logan Labs. He's The Man here at GW for getting a jump start on that.

Good that you have not used a fungicide. That would have called for corrective action to normalize your soil again. And you have not overdone anything with the other apps.

In my opinion the Scott's plan has you spending too much, too often. If you water deeply/infrequently, mulch mow at the right height, and fertilize with chems on Memorial Day, Labor Day, and Thanksgiving, then you likely won't need insecticide or herbicide. I don't see the Scott's plan as harmful, just more than you should need.

You don't have a serious problem with your lawn. You might have mowed even lower for your last and first cuts to get rid of the chaff. Then raise it back up to the highest or one notch lower than highest. Many people here would kill to have a lawn that nice. This guy for example...


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RE: Too much dead grass

>Some folks do cut cool season grasses a little lower than usual in preparation for winter, say at 2 to 2.5 inches

I have to do that to get the last of the unmulchable leaves off the lawn at winter time. Any dead grass (and the rest of the mulch goodies) are eaten over the winter--by spring, it's gone. Bet it's too cold for that in zone 4! My lawn even eats acorns, if the crop isn't too big.

Give it more fertilizer--organic or the regular stuff, your choice.

Mow it at 3-4 inches--2.25" is still WAY too low. 3" is the dead minimum for your lawn. I think I've got mine at 3.5"--whatever the highest setting is!

And water deeply once a week--zone 4, unless you're in the high desert, will never need more.

Honestly, your lawn will look amazing within the year if you do that!

You can't do anything about grass turnover, as long as you aren't unduly stressing it, but you can do something about making the green stuff greener and grow better to make it unnoticable. A thick cover of green makes the stuff underneath stay more moist and rot it really fast.


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RE: Too much dead grass

So I appreciate all the advice so far. My lawn is already starting to look much better as it gets longer, but there are basically two reasons I want to get to the root cause of all the dead grass.

1. Even when the lawn is doing great and looking green, spreading the blades apart just a little causes you to see all the discolored dead stuff underneath which makes the grass a little less green overall (but only is some sections)
2. So my wife will stop bugging me that our grass is dead every spring and that we need to power rake. She compares it to the neighbors who don't seem to have the dead material issue and thinks our lawn is terribly sick.

Here is a picture I took today. Notice in the top right corner where the green is a much darker color ( the difference is less pronounced in the picture). That corner doesn't seem to have the issue and it is already a thick lush green with no dead material. And I promise dchall_san_antonio that I am not posting this to rub it in, my wife is from San Antonio and she would probably rather have your yard.

In the end, I think I will definitely try to let it grow just a little longer but still cut it shorter in the fall until I am sure the dead material issue is not more. We'll see how a more diligent fertilizing regiment will fare this year. Thanks again for all the advice.


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RE: Too much dead grass

AaaaHA! Spousal pressure. 15-yard penalty for withholding information! Because without that critical information you were starting to sound like a whiner. My poor lawn is in such bad shape. Baloney. Your lawn looks better than most.

You need to power rake it to satisfy her. It will never end until you do. Find a time when it is growing well and do it. She'll get off your case and you can watch more golf next spring. I'd go as lightly as I could, though.

If you want to take your lawn to the next level of greatness, send a soil sample to Logan Labs in Ohio. Any other lab will charge you $75 or more to get the same results you get from LL for $20. Then post your results here for advice as to how to tune up your micro nutrients for a better lawn. It might be possible to have a green Kentucky bluegrass lawn all year round...like this guy (MorpheusPA). Photo taken in SE Pennsylvania on April 11, 2011. He tests his soil at LL.


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RE: Too much dead grass

Maybe you're overfertilizing.

In Iowa State Professor Nick Christians textbook called Fundamentals of Turfgrass Management, (not to be confused with the similarly titled Turfgrass Management by Penn State Professor A. J. Turgeon), Professor Christians writes:


Excessive nitrogen (N) fertilization is the management practice that is most likely to contribute to thatch accumulation.

If dead organic matter, stems, stolons, rhizomes, and roots build up faster than the beneficial microbial populations of bacteria and fungi can break them down, thatch will accumulate.

Excessive watering can be a contributing factor. Some moisture is necessary for aerobic microbial activity, but so is oxygen. Excess moisture results in anaerobic (low-oxygen) conditions, which in turn has a negatvie effect on the microbial population that plays such an important rule in natural organic matter breakdown.

Other causes of excess thatch:

"Low-pH conditions (below pH 6) can cause imbalances in the microbial population that may result in a reduction of organic matter breakdown."

"Macroorganisms, such as earthworms and burrowing insects, can be critical to the processes by which organic debris is broken down, as are the microorganisms. These larger soil organisms play an important role by burrowing through the thatch. This results in a natural aerification and a mixing of soil microbes through the organic layer. Management practices that reduce these macroorganisms will contribute to thatch buildup"--like the use of chlordane and other chlorinated hydrocarbon insecticides. Their use in the 1970's was "notorious for contributing to thatch accumulation."

"The cholrinated hydrocarbons have been replaced by other insecticides that are less persisitent and less damaging to the living component of the soil. But these newer materials should still be used with care."

"Fungicides have been suspected as possible causes of thatch because of their effect on the fungi. Some fungi cause turf diseases, but most of them are important saprophytes--organisms that feed on dead organic material. There is little evidence to date that the fungicides have a major impact on thatch development if they are properly used. Where there is sufficient oxygen and moisture in the thatch, there appears to be little effect of the fungicides on the ability of the microbes to naturally degrade it."

But let's not villainize thatch too much:

"Moderate thatch layers of 1/2 inch or less can have some benefits."

By the way, I read somewhere else that laying a thin layer of compost can help reduce thatch. There are lots of beneficial bacteria and fungi in the compost that will decompose the thatch.


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