Question
Hi, I live in NJ with a lawn on clay soil. I've read your praise of clay and your recommendation of adding organics to clay. If I already have a lawn, do I just apply the organics on top of the lawn? or do I need to break up the lawn in some manner by digging or tilling? As we enter Spring, my lawn is brown and thatchy and am hoping it will turn green again. This year, in addition to the lawn care of watering and fertilizing and mowing, I'd like to look into improving the drainage of the lawn on clay soil.
Thanks.

Answer
Thatch.... caused by your Clay soil?

Sure, you could have watered too little.  Mowed too high.  Fertilized with the economy bag of industrial strength Nitrogen.

But grass in Clay can create a thatch problem with a domino effect.  Water runs off instead of reaching roots.  Fertilizer never gets past the thatch.  The lawn begins to fail.  By summer's end, a lot of grass is ready to throw in the towel.  By winter's end, it's gone.  You get diseases, unfriendly insects, and a lawn that qualifies as a "Before" picture.

Please tell me you did not use Pesticides to get rid of Grubs, etc.

Pesticides do the same thing to your grass.  Roots can't decompose properly.  They sit there, with nothing to break them down.  No microbes.  Did you know that Fungicides destroy Nitrogen-producing bacteria?  Earthworms leave home for greener pastures.  Birds avoid your house.  The soil is dead.

The traditional way of dealing with this is to aerate and -- dare I say it -- de-thatch.  But that won't solve the your Clay/Thatch problems.

If you have been doing the traditional lawn care routine, you have been doing something like that Scotts 1-2-3 "program" or whatever it's called this season, grub killer, anything to get you to spend money on their stuff.  All of these products wipe out your chances of fixing your Clay soil.  Just one application will terminate your lawn.

And because your Clay plot needs organic matter to live up to its potential as a terrific, lawn-of-your-dreams garden soil, you are making it impossible to reach that point even when you fertilize with chemical fertilizers -- they instantly destroy microorganisms in the soil.

Plus you cannot by definition get organic matter into a soil where everything is dead.

Are you with me here?

Believe it or not -- I understand you may be hearing this for the first time, but perhaps you already know this -- there's some wonderful Fungi and Bacteria and Insects down in that Clay soil... IF you have not killed them.

If you did, just stop.

Start off new.

You may have killed 99 percent of the Earthworms.  If there is ONE EARTHWORM left, Shawn, that Earthworm has the potential to hatch as many as 1500 offspring in one season.

OK. I sit corrected here.

You need 2 Earthworms because they do not self-sow, you need at least 2 music-making Earthworms to get offspring.  Assuming they find one another.  Usually that's not a problem.

University of Wisconsin Horticulture Dept(http://www.uwex.edu/ces/wihort/turf/Earthworms.htm) notes, "Many species of Earthworms deposit their casts beneath the soil surface within their burrows, where casts contribute to pedogenesis."

(Pedogenesis - "the process by which soil is created" [Wikipedia].)

"Species that excavate permanent, vertical burrows, however, deposit their casts on the soil surface, where they play a greater role in soil profile development.  In addition to benefitting soil structure, casts also provide nitrogen in a useable form for other organisms that decompose organic matter on the soil surface.  This interaction stimulates an accelerated decomposition rate, which helps reduce thatch buildup."

Let's read that again, Shawn.

"This interaction stimulates an accelerated decomposition rate, which helps REDUCE THATCH BUILDUP."

Now, Shawn, if you are growing Zoysia in your New Jersey lawn -- which does turn brown in winter and thatchy all the time -- then you're in trouble.  Do you have neighbors growing Zoysia that might have migrated to your side of the yard?  Grass doesn't get more aggressive than Zoysia.  It's one of its charms, actually.  Weeds drop like flies.  But it thatches up and turns brown.  Many people don't mind, and many people do.  If you have Zoysia and you are holding back that little detail, Shawn, speak now.

Meanwhile, let's continue and hope you can come clean about your grass.  You put it down, yes?  Was it Bluegrass?  Fescue?  Rye?  Zoysia?

It would help understand the state of your Clay soil and what else you have there with the Clay, besides thatch and some brown spots.

Aeration?

Let's get back to U of W's Earthworms website: "Earthworms also act as effective agents of soil aeration.  As they penetrate the topsoil and proceed downward into the subsoil, they may increase the soil-to-air ratio by eight to thirty percent."

I tell you, Shawn, when the Lord made the Earth, He really knew what He was doing.

You don't need those bags of fluffy white toxic powder.  Those powders with skull-and-bones graphics on the back.  You need more Earthworms.

If you feed them, they will come.

Earthworms live on the organic content of your soil, so you must get your soil in shape.  Mechanical aeration won't do that.  In fact, by disturbing what soil structure you have already, it would make things worse.  No matter what they tell you.

And don't even think about putting Sand down.  It will instantly bind with the Clay to create a strong, impenetrable foundation just perfect for parking.  You'll need dynamite to break it up.

But back to our friendly Earthworms.

Don't underestimate the power of the Earthworm to fix your soil.  Given enough humus, one Earthworm can produce 10 lbs of casts each summer.

Some ORGANIC Humus -- you will not find this in Home Depot, sir -- as a generous top dressing (an inch would be terrific) over your grass this spring will set the groundwork for Earthworm Heaven.

But there's something even better that I want you to put on TOP of that Humus.

Ready for this?

I hope you like coffee, Shawn.

Because Earthworms LOVE Coffee grounds.

I'm not kidding.

I know what you're thinking.  Coffee is acidic.  People who want to grow Blue Hydrangeas and Blueberries are advised to use Coffee Grounds to get their soil pH wayyyyy down.

But that's not really true, Shawn.  The pH of a cup of Starbucks Ethiopian Black Coffee is around 6.3.  The Coffee GROUNDS have a close-to-neutral pH.  Around 6.7.

Neutral pH is 7.

How?  Popular science says that the Coffee leaches out of the used grounds and most of the acid goes with it.  Whatever.  6.7 is a grass-happy pH.

Starbucks gives these grounds away for FREE!

Take a garbage pail down to your local friendly Starbucks and get their day's supply of grounds.  They'll be glad to see you.  Less work for them.  And very pro-Earth.  Good for business.  Great for your Clay Soil.

Earthworms LOVE Coffee grounds, Shawn.  It's a known fact.

Finally, you don't want to get started with a weed problem.  Get yourself some Corn Gluten Meal pre-emergent weed-killer.

This stuff is incredible.  It interrupts the germination of seeds; then it decomposes for the rest of the summer into grass fertilizer.  Slow, steady Nitrogen doses, all summer long.

When you mow this summer, promise me you won't catch the clippings, Shawn?

Leave those Nitrogen-rich grass clippings where you got them.  The Earthworms will appreciate your efforts even more.

In autumn, over-seed.  By then, your Earthworm population should be well under way.  Your Clay soil should be exploding with microbes.

Let's recap:

1.  Super-duper Humus asap, 1 inch (don't worry, it will look ugly for about 2 weeks and then the Earthworms will get to it)

2.  Starbucks over the Humus (ditto)

3.  Corn Gluten the first DRY day after the Forsythia starts to bloom.  Make sure you have it in the garage ready to use.  You don't want to spend the day shopping for this stuff.  Get it this weekend.

4.  Mow faithfully, leave the clippings, water deep, be patient while the Earthworm stomachs digest your coffee and humus.  Love your healing lawn.

5.  Get fall grass seed bags -- preferably a new strain from a specialist online like Seedland.com, so you can over-seed.

6.  Order more seed and be ready to put down in the early autumn.

If you want to speed up the de-thatching, you can do this in a way that won't turn off Earthworms.  Outsidepride (http://www.outsidepride.com/store/catalog/Liquid-Dethatcher-p-1-c-383.html) sells a liquid-dethatch that is basically a lot of microbes that will break down thatch cellulose and lignin quicker.  There are other companies with similar products -- I wish I could recommend the best but I have not used them on my own lawn and there is no published Consumer Reports advice on these.  If you can buy it locally, even better -- these garden centers need to get with the program and they'll do that quicker if they see it makes them money.

What should you NOT do?

EVERYTHING ELSE.

No Fertilizer, Shawn.  I don't care how beautiful you think it's going to look with some artificial whacko greenup drugs out of a bag.  This will stop your progress with your soil.  The salts in these Urea based Nitrogen fertilizers are murder on microbes.

And remember:  No fertilizer can make your grass greener than it is genetically pre-programmed to be.

People forget that.

There's a lot of work to do here, Shawn.  And I know you're not reading this stuff in the local newspaper -- where major multinational corporations spend millions (billions?) in advertising dollars for their chemical lawn products.

But there is a right way and a wrong way to do this.  This, my friend, is the right way.

Trust me.

And when you're done, a year from now, send me a picture of your smiling face.

Any questions, I'm here.