Question
I live in North Carolina and I'm trying to establish a lawn in a clay sand like surface.  I've read some of your articles about tilling this type of surface.  I've had the area plugged several times, then seeded and fertilized but never a good stand of grass.  With it being mid March, is this a good time to till or should I wait until the fall?  

Answer
Hi Jeanie
If it is too tight because of too much clay, you probably need to till in some humas and peat moss, and maybe some bark mulch to loosen it up.
If it is not too tight, but has too much sand, and doesn't hold the water long enough for the grass to benefit, you might need to till in some humas, and maybe some compost and/or top soil to tighten it up a litle.
Too much sand and too much clay are the worst problems, I think, because too much drainage or too little are neither soils that are going to let anything grow well.
Pick up a handful of soil when it is dry ( but not like it has had no water for a month) and sqweeze it in your hand.
when you open your hand, the soil should form a clump that most of it stays together, but quite a bit of it crumbles in your hand, not a firm ball. That is what it should do. If it stays in a tight ball, too much clay. If it all falls apart and forms little to no clump, too much sand.
I till any time of year I am going to work with anything where I need to till.
If you are going to plant a vegetable garden, tilling raked up leaves etc in the fall makes some good compost to start the spring garden.
I recommend an organic program, because natural methods of building up soil is very successful. chemical methods just mean work, work, work, all your life, and minimum results.
the beneficial microbes that enrich soil work all the time.
Chemical fertilizers feed the vegetation, wear out, then you have to do it again.
Putting an organic fertilizer, will help until the chemicals get out of the soil, and the beneficial microbes have time to start growing, and working. Put diown the sugar along with the organic fertilizer, then every spring and fall put down more sugar, at the rate of 1 pound per 250 sq.ft. of lawn and garden. this feeds the microbes, and the microbes enrich the soil.
when the soil is very rich, it will grow anything but weeds. Weeds love poor soil, and will not thrive in rich soil.
I am putting down an organic fertilizer this year. This is the first fertilizer I have had to put down in about 7 or 8 years, I have just put sugar each spring and fall.
I have had no weeds come up in my yard for the last 6 or 7 years.
The first year I used sugar, I had about 50% weeds. They began to fade away in a couple of weeks.
The next spring, about half as many weeds came up, and in a few weeks were gone.
The next year after that, very few weeds even came up, and no weeds in the years since then until now. I have seen a few patches of Dallis Grass coming up, so I will fertilize with the organic fertilizer, put down the sugar and water it all, in together, and I don't expect to have to fertilizer for another 5 to 7 years.
Before, using chemcal products for gardening, I had dandelions, dallis grass, crabgrass, clover, chicweed, johnson grass, and even poison iny.
Haven't had those since I started using sugar.
Build a healthy enviornment for toads, lizards, grass snakes and other beneficial critters, and you will not be bothered by insects that destroy your lawn.
I see maybe a half dozen to a dozen grubs in a year. I used to have grubs like I was TRYING to raise them.
Baking soda is a much more effective fungicide that any chemical ones on the market.
I seldom see even the lizards. I can't stand to even look at snakes, so I rustle high vegetation with a long stick before I go into it, to scare the snaks away.
I keep all those big black pots my shrubs come in to plant things I am growing from seed in , as they get bigger.
I keep them stacked out behind my garden shed. Snakes like to be in them for some reason, so I jiggle the top one and I can hear the little snakes scurring down to the next one. But I don't have to see them or risk one of them touching me.
I am a chicken about that.
My toads eat the slugs, so that makes them my best friends.
    Watering is the most improtant factor, I think.
shallow watering forces roots to come close to the surface to get water.
That exposes them to heat, cold and draought damage.
The roots come to the surface and die, and trap other debris, and that is what causes thatch.
Water deeply and the roots will go deep into the soil. That gives them protection from the elements and you won't have to dethatch. That is a heck of a hard job.
Organics is the best labor saving device for gardening, and the things you use cost a LOT less that the chemical products.
I always water to a depth of at least 6 inches, and try to water again when the top 2 inches of soil are dry, but if you don't get it watered THAT day, you are not going to get a brown and/or dead lawn. There is still some moisture down where the roots are.
When we have our hot summers here in North Texas, and the temp gets up in the 100+s I water only once a week.
I water with a soaker hose. I turn on the water, and leave it on until it starts to run of onto the sidewalks etc, then I turn it off and let it soak in for an hour or so, then turn it on again, and keep this up until, it is soaked deeply enough.
Also, watring with a sprinkler wastes a lot of water. when the telp get into the upper 90, 50% or more of the water evaporates. It never touches the ground and gets to the soil but your water meter registers it.
You can purchase a water meter to stick in the ground and guage the amount it is soaked in. I Walk on it. When it is that well soaked, it gives, when I walk on it. like I am walking on a softer carpet. I don't want water to squish up out of the ground, but just for my footsteps to go down, like maybe walking on a sponge about 2 inches thick .
Walk on it before yoy water, water deeply  and when you know it is soaked enough, walk on it, and you will soon be able to guage just how deeply it is soaked in by how much your steps sink down.
As far as how late to till. I have tilled up ground to plug in St. augustine here in the late summer.
We usually don't get out first freeze till around thanksgiing, so my plugs will have time to establish roots, so i would not hesitate to till and plant plugs as late as Late August. It will have a couple of months to set down roots. When growth starts, I will put an inch or two of topsil on top of it, just so the blades are sticking out a little. that puts the roots about an inch deeper after I water, and it also helps it send out some more runners to thicken it up. When yo add soil on top of gras, you want to make sure most or all of the blades are sticking out so it can get sun.
I hope I have helped.
If you still hve questions, or need anything i have said clarified, write anytime.
Charlotte