Question
QUESTION: Long Island, saw a post from you last year where you had some good info about how to condition the soil for an existing lawn.

In the response you also mentioned, if you have NC red clay, then you need to do something different...

I do have red clay so I am wondering what would you do that is different?

I also broke one of your suggestions about using chemical fertilizers. What is a good organic fertilizer?

Grass is tall fescue. I have spread gypsum before, but it seems like there should be something better to use.

The gypsum was pelletized so it was easy to spread with my rotary spreader.

How do you go about spreading compost or humus on an existing lawn?

Thanks, Sam

ANSWER: I'm guessing that you figured Gypsum would break up your Clay?  Common assumption.  In fact, Gypsum won't improve any Soil, Clay or otherwise, unless the Soil is high in Sodium.  

Daryl Pulis, as 'Mrs Greenthumb' the pre-eminent expert on Georgian gardening, has recorded her battle with the Red Clay on her website:

www.mrsgreenthumb.com/articles.html#clay

Writes Ms Pulis: 'Southern Red Clay is very poor in microorganisms once it's cleared out for home development... Soils vary in the Carolinas. Even in very short distances you can find Red Clay, rich loam, gravel and/or Sand.  Once again, we have it all here.  If you don't inherit good Soil, you'll have to purchase it or create it by adding organic material until it is rich and loamy.'

Let's try to understand your Red Clay.

First, a new word for your vocabulary: Cecil.

Wikipedia has a nice little picture of Cecil Soil, but you don't need that.  You are probably sick of looking at this stuff.  So we'll jump to the explanation of WHAT you're looking at when you go outside and put shovel to Soil.

They write on Wiki, 'Cecil Soils support forests dominated by Pine, Oak and Hickory, and have a Topsoil of Brown Sandy Loam.  The Subsoil is a Red Clay which is dominated by Kaolinite and has considerable Mica.  ... Indifferent land management has allowed many areas of Cecil Soils to lose their Topsoils through Soil erosion, exposing the Red Clay Subsoil.  This Clay is amenable to cultivation, responds well to careful management ... however, in common with other Kaolinite-dominated Clays, it has little ability to recover from Soil compaction.  Total Potassium in the Cecil is higher than typical for Ultisols due to the presence of Mica.'

Very different from our official N.Y.S. Soil, 'Honeoye':

www.urbanext.uiuc.edu/soil/st_soils/ny_soil.htm

OK, OK, I digress.  Back to your Cecil.

Believe it or not, someone has a magazine for Gardeners who grow in Cecil:

www.cecilsoil.com/current/1staff.html

Don't get excited yet.  These are people gardening in Cecil County, Maryland, and although it is called Cecil Soil Magazine, that state is distinguished for its Sassafras series Soil.  Not Cecil.  Publisher Ed Belote sends it gratis to U.S. soldiers overseas for their reading pleasure.  Just fyi.

Standard procedure for this problem is to amend, like there's no tomorrow, with organic matter -- Peat Moss, Compost, Humus.  If you have a Lawn established already, this is a modest film that goes over the Grass, a 'top dressing' that works ITSELF into the ground.  Earthworms handle much of the labor.  Odd, but true.  Having orchestrated your own Sting operation (the effect of chemicals on the invertegrates underfoot), this will be somewhat slower than normal.  Just don't do it again.

The difference between chemical and organic fertilizers is like night and day.  Chemicals are potent, very fast (practically instantaneous), and generally short lived.  Organics are mild (which some people translate as 'weak' and 'in-efficient'), long lasting, and practically permanent.

Chemicals go straight into the plant.  Organics take up residence in the Soil, feeding microbes like a decomposing Fish or Twig or Apple; the microbes generate plant nutrients at a rate the paces with plant's metabolism, faster in Warm Soil, and slower in Cool Soil.

Turftype Tall Fescue gets a lot of research these days.  Its incomparable root system and incredible drought and traffic tolerance are why.  You're going to love this Grass.

At some point: TEST YOUR SOIL!  You've seen that here if you've found the Red Clay questions.  I know you have.  Are you in North Carolina?  Do that here:

www.agr.state.nc.us/cyber/kidswrld/plant/soiltest.htm

Warning: The note that 'from late fall through early Spring, processing may take several weeks due to the heavy sample influx from farmers at this time.'

Any questions?

THE LONG ISLAND GARDENER

---------- FOLLOW-UP ----------

QUESTION: Long Island,

thanks for the great response!

Is there an easy way to spread the compost on the existing lawn? Do I literally just spread a thin layer with a shovel and then rake it in? I have about a 1/4 acre to cover.

Thanks, Sam

Answer
I'm very sorry I didn't get to this sooner, my friend.  I am away for the week, and my internet access is severely limited.  I hope you were not holding your breath.

Your description will work fine.  A thin layer with a rake or shovel will do the trick.  Cool Season Grass this time of year grows like a house on fire, so it needs Sunlight more than ever, but a thin layer won't interfere with that.  Do it again next Spring.  If you have a good Earthworms population, they'll do all the mixing for you.  Good luck and keep me posted.

THE LONG ISLAND GARDENER