About Long Island Gardener Expertise How to grow the Perfect Lawn? If you live in the Northeast/Atlantic Coast, I have intelligent answers on grass selection, fertilizers, soil care, weed control, and lawnmowers. Although I have degrees in related fields, a person's real gardening skills are learned from trial and error. More important, I am strict about not using chemicals in the garden. Organic gardening is not just earth friendly and healthier for you, your children and your pets. It's less expensive and easier. You read that right. Less expensive and easier.
Experience Homeowner for 15 years, 30 years of gardening for personal pleasure, college credits in horticulture and botany, volunteer docent at the local botanical gardens, and a whole library of gardening and landscaping books at home some 100 years old.
Question QUESTION: I have an on-going thatch problem. My local extension office (Cornell U.) advises against power-raking or dethatching. I assume they mean heavy raking, not vertical cutting. The Cornell Extension advises treating thatch by aerating with core aerator, which I do...but it doesn't seem to help. I know thatch is not from grass clippings, is caused by imbalance of water, fertililzer, is dead roots, etc.
I seem to have a lot of matted grass after the winter snow melts. My lawn (especially where the thatch is worst) was "tan" much longer than my neighbors. Even after the grass greens up there seems to be a lot of this tan (dead?) matter. I've a few questions:
1) is this matted grass the result of the thatch?
2) does this matted grass become thatch?
3) do you agree with the local cooperative extension office contention that there is no need to rake the lawn in the spring?
ANSWER: Excellent questions, my friend. I'll begin with a few basic tips, but for the real story you will have to answer a few questions, the first of which is: What Grass do you have?
Now you don't have to know the answer, but if you do, it would certainly help.
Second question: I assume you are somewhere in the Northeast? Since you contacted Cornell? But I have to confirm -- Cornell is world famous and you could be growing Grass in Fiji. Please confirm and even better can we narrow this down to a County and State? It helps to know your latitudes and longitudes for Grass purposes. No point going on and on about what it 'might' be, we should figure it out.
And Third - What IS the state of your soil? Please tell me the Cornell advisors have established that your soil is in excellent condition and that Thatch is your problem without a doubt?
OK. Now to your questions.
1. Is this Thatch? Well, I hope you will answer my questions, but we do have to consider the possibility that it is not Thatch. I do need to know what you are growing (some does not produce Thatch). Where you are growing it (to narrow down the list). But we can meantime consider this as a multiple choice question.
Every now and then I quote a paragraph from the Winter Damage To Home Lawns essay at the University of Illinois Cooperative Extension: 'Snow mold damage can also be very visible on many lawns as snows recede in spring. Both gray (Typhula blight) and pink snow mold (Fusarium patch) may occur in northern Illinois. During the wet, cold weather of early spring, snow mold may be highly visible as matted, crusty looking areas. As conditions dry out, snow mold will gradually disappear but infected areas may remain in the form of weak or even dead turf.' Sound familiar? Look familiar? What are the similarities and differences? What do you see out there?
2. Does matted Grass become Thatch?
Let's see where Thatch comes from. There is a very good, clear website that a good fellow named Jim has posted that will tell you All About Thatch (http://www.members.aol.com/groundkprs/Thatch/FindThatch.html): 'We all have looked down on a lawn and seen the blonde laid down blades of grass. Many refer to this as Thatch, but this is not real Thatch...Thatch is a tightly intermingled organic layer of dead and living shoots, stems, and roots that accumulate just above the soil surface.' Jim posts excellent photographs that will help you determine once and for all if you have a Thatch problem or if it's something else. He points out -- and he's totally correct about this -- that 'true Thatch removal is a very destructive process. Ask the southern guys who have to do St Augustine regularly.' St Augustine is a Thatch factory. If you are living in Cool Season Grass territory, Rick, you won't have that Grass and we won't have to address the ways of dealing with St Augustine Grass. If you're growing Zoysia, it's another story. Bluegrass, another story. Please advise.
De-Thatching is a job to undertake when your grass is growing vigorously. That means late spring-early fall scheduling. Most authorities caution us that de-Thatching, in the EARLY Spring, or in very dry weather, does more harm than good, stressing your Lawn.
University of Illinois posts its positions on Thatch Removal: 'An efficient method of thatch removal combines topdressing and core aerification. Allow the soil cores to air dry on the turf surface before crumbling and spreading them with a hand rake, broom, or by dragging a section of weighted chain link fence. Additionally, coring serves to mix soil into Thatch which can also speed Thatch breakdown.'
Provided, of course, that you do have Thatch, which remains to be seen.
You sort of touch on a potential cause of this with your question: 'I know Thatch is not from grass clippings, is caused by imbalance of water, fertilizer, is dead roots, etc.' So you are clearly versed in much, if not all, of this information -- which gives me pretty strong reason to assume you do in fact have Thatch in a cool season grass. There's only one way to get that. Over-fertilizing with SCOTTS! Grub-killing with SCOTTS! Weed-killing with SCOTTS!
Oh No!
Which brings us to question #3. Do I agree that you do not need to Rake a lawn in Spring?
Are you asking this because you do this as a matter of routine?
Totally, you do not need to Rake routinely. Of course, I'll bet Scotts makes a great Power Rake that you can buy at Home Depot for doing this exercise that you do not need to do, but you don't need one. In fact, you should not get one. Because the best thing you can do to eliminate Thatch caused by a Scotts Fertilizer addict is to leave your poor Grass alone.
Fix the soil. Do something about that 'imbalance' -- which I translate to mean 'use of things I should never have used to wreck the balance of Nature around my own house.'
If you DO have Thatch, you should deal with it asap. De-Thatching is a job to undertake when your grass is growing vigorously-- like, NOW.
Very simple.
First, I agree with Lawn Jockey (http://www.lawnjockey.net/dethatch.htm): "The current, and preferred method of de-Thatching a lawn consists of: aeration, organic fertilizing, Liquid Organics applications, or topdressing with compost. Not only is this method more cost effective, it builds a healthy soil that retains nutrients and improves the natural defenses to diseases and pests."
(http://216.109.125.130/search/cache?p=dethatch+organic&tab=Web&ei=UTF-8&fr=my-ve...) Take care of that.
Now, Rick, maybe you know, or maybe you don't know. But I'll tell you right here: Chemical Fertilizers and Pesticides lay the foundation for a Thatch problem on Grass not prone to that. Which means: YOU are the cause of your Thatch problem.
OK, I'll bet you are thinking, Why would bug killer or
weed killer or fertilizer cause Thatch? That's the first time I've ever heard anybody say that. That's ridiculous!
So let me tell you how.
Thatch is dead roots and plant material. Those things decompose naturally. They ARE soil. Go out to the Great Plains sometime. Take a good look. See any Thatch? I don't see anybody running through the Appalachian Forest to
de-Thatch the soil. They don't Power Rake the Great Plains in the spring. Right?
But you are considering that you should do that - ROUTINELY!
Why?
Because the tiny, wiggly, microscopic animalcules in your soil that decompose roots and stems are DEAD.
Why?
Think back, Rick. You love your Lawn? You love to stock up on all those Scotts powders and potions and pesticides, herbicides, I'll bet you even had to use fungicides every spring? The 1-2-3 Scotts system?
You kill EVERYTHING in the soil that way. Every time you run through the lawn with a spreader. Those poor, defenseless microbes, they have no chance whatsoever.
You, sir, are the problem. You made the Thatch. And I'll bet it was a LOT of work. You should stop doing that. Then you won't have a Thatch problem.
So, fill me in, here. Tell me what's going on with your Lawn. And if this last scenario is close to the truth, I'll tell you how to stop making Thatch and fix your soil. Intelligently. NOT with Scotts. With Science, sir. The Earth is Round. The Eagle Has Landed. Do you read me? Over.
---------- FOLLOW-UP ----------
QUESTION: Hi:
I tried to reply but you were on break...probably recovering from reading my long email. I am in the champlain Valley (Plattsburgh NY...across lake Champlain from Burlington VT), 20 miles south of Canadian border. So, cool season grasses. I did email the greenskeeper and he said my aerating probably hadn't worked because it needs to be done 4 times a season and probably would take 4 yrs to show a difference. So now I know I don't have to think about raking out that deadish grass in the spring. I will continue to aerate in the fall (can't afford 4 times a year), and will use organic fertilizer. so, my four questions are:
1. I read that compost without first aerating actually makes thatch worse. So, I will use compost topdressing after I aerate around labor day. Does this make sense?
2. Cornell Cooperative Ext says Corn gluten may act as fertilizer but does nothing for crabgrass or annual bluegrass (I have both...especially ABG). I wrote the guy in IA who did the research on gluten. He directed me to a guy at Cornell who never did reply. Do you have any suggestions regarding annual bluegrass?
3. My local Agway sells a product called Milorganite fertilizer. Is this an example of an organic, slow-release fertilizer? If so, can I put this down at this time of year, or do you suggest only fall fertilizing? Since my thatch areas can have developed from overfertilizing, should I not fertilize these areas even with organic?
4. Is there ever anyway to send you email pictures of grass problems?
ANSWER: Plattsburgh -- Postcard country, stunning views, clean air and water, Paradise. What a lucky guy.
I do not know who the greenskeeper is but he could not have possibly told you to aerate 4 times a season? No way. Nope. Impossible. Call Cornell and tell them that. They'll have a good chuckle over that advise. I did. Glad you finally got through, hope it's not too late!
Aerating every 4 years? Maybe that's what he said.
Cornell is giving out some weird advice. Next time you speak with them, find out if they're volunteers -- 'master gardeners' retired from the Post Office, the local school, accountants, senior citizens who meet at the monthly Garden Club. Here's the science on Corn Gluten Meal and what I think they may have meant, if they knew what they were talking about, is that like ALL pre-emergents, Corn Gluten Meal does NOTHING for Weeds or Grass that's growing already but it will stop EVERYTHING from germinating including ALL annual Bluegrass and ALL Crabgrass:
This was a test conducted in 1995 at Iowa State University of how well Corn Gluten Meal keeps 22 weeds from sprouting. They found: 'CGM reduced plant survival, shoot length, and root development of all test species.'
Best results were seen against Black Nightshade, Common Lambsquarters, Creeping Bentgrass, Curly Dock, Purslane, and Redroot Pigweed. Twelve monocotyledonous species tested, including Quackgrass, Large Crabgrass and your Poa annua. The CGM was tested two ways: (1) Mixed into the top 2 1/2 cm of soil and (2) sprinkled over the soil surface, as you would with a spreader.
Velvetleaf and Barnyard Grass were toughest of the Weeds tested.
Researchers observed: "The efficacy of CGM for control of a particular weed ... depends on the amount of CGM applied. Broadleaf species were generally more susceptible to CGM than grasses ..."
The majority of Crabgrass plants are annuals. If you wait, they will be out of commission next year. Remember that as you stare at them this year. Too late for this year, but if you don't let them seed, and you don't let the set seeds germinate, you will hopefully see the last of them. Corn Gluten Meal applied in the spring will stop that from
happening again. CGM is also a great Nitrogen fertilizer and it builds up your soil.
Milorganite is a decent slow-release semi-organic fertilizer that some purists don't like because it has the potential to contain some metals. I contend it's a step in the right direction and I have used it on my soil. It is not as good as Corn Meal Gluten decomposing, because CMG conditions the soil a little better. Milorganite is a nice option right now; it's too late for CMG.
You did not say what Grass you are growing -- did you? I don't see it here. Did I miss it? Just wondering what has built up Thatch.
Thatch needs microorganisms to break down, and Nitrogen fertilizer won't help you there. Slow release Milorganite or CGM take a lot of time, so I don't think this is something you have to hold up or worry about. But you need more organic matter in your soil to get the Thatch broken down. There are 'organic' Thatch breakdown boosters which are basically bacteria and Fungi specialists, and I think it would be a good idea to pick up a bottle of that stuff. You'll find it somewhere in a garden center.
You can send me photos of anything -- I'll be happy to look at them. Send me a private question and I'll give you an email address. Agway has a lot of great, low cost products and it's great you have one where you can buy everything. Maybe they have straight Corn Meal Gluten. Otherwise it's sold as 'Concern Pre-emergent Weed Killer', 'Cock-a-doodle-do Organic Weed Killer' and other things, with the words Corn Meal Gluten on the package somewhere. Don't confuse this with Cornmeal. They are very different. Believe it or not.
Good to hear from you, sorry you had trouble getting through. I was backed up big time in my Questions mailbox and I had to slow down to 1 or 2 a day. I'm freed up now. Please remember to Rate me when you get this -- I would like to shoot for the AllExperts of the Year list at the end of the year, I need a 'Nomination' for that. I'd appreciate it. Thanks for writing, long questions are filled with details and very helful -- Just be ready for a long answer!
---------- FOLLOW-UP ----------
QUESTION: Hi
I wonder if you got my original reply to this reply from you. I just got an ask the experts email that seemed to just be this reply from you again, with no additional info...at least I couldn't find any links to anything.
I did send a reply to this email from you, with a couple of other questions. I wonder if you received it? In my reply I said that on rereading the letter from the greenskeeper he had said "2 times a year" with FOUR passes with the machine....not "4 times a year". also, I went into some detail about my communications with Nick Christians, the IA researcher who first came up with the corn gluten, and then with a researcher at Cornell named Rossi. Did you get that email from me? I hope so. But, if not, I'll write it out again. My email also had a few follow up questions about applying corn gluten now, about the fall timing of corn gluten for annual blue grass vs. aerating for thatch, etc.
Rick
I also said I had pictures of some really wierd, stiff grass that came up where I planted Scott's SUNNY last fall (50% bluegrass and 50% perennial rye, but this stuff looks like neither and I wonder what went wrong.)
Answer Sounds like something is brewing between the Ivory Towers in Iowa and Cornell, don't it?
Iowa holds a profitable little patent on Corn Meal Gluten Weedkilling. Rossi meanwhile seems to have this project with Borax/Boron still in development. Certainly Cornell should have had no trouble replicating and re-replicating the Iowa results, and yet I can't find anything to indicate this ever happened.
Doesn't mean it's not there; just that I haven't found it yet.
I would expect the consumer magazines like Rodale's Organic Gardening would pick up immediately on any suspicion of the efficacy of CMG. Instead, I am certain I read subsequent Iowa State studies that looked further into the chemical dance that ends with permanent interruption of seedling growth. You're right, this is fascinating. I must find out more about it. Thanks for enlightening me and I will let you know what else turns up. Maybe these people just don't like each other, who knows.
