There is another concern, that you may or may not have heard of, and that deals with the soil's natural bacteria and fungus. If you have a woodland, there is a type of fungus that grows naturally, and a type of bacteria that grows naturally, let's call them Type A. On an established lawn, there is a natural type of fungus, and of bacteria that grows naturally, but the problem is that they are Type B. Now that the woods are torn down, there is plenty of Type A fungus beneath the soil, but not Type B, which you need. Mycorrhiza is the specific type of fungus that you need: it attaches (grows from) the plant roots, outward into the soil, and helps the roots do a better job. Google that word, and you can find a lot of articles about it. Here's a link to Bio-Vam, which is a product that I have used, with great success. My office lawn was installed with topsoil that had apparently been sitting around in a bin somewhere for a year or two, and nobody could grow a lawn on that soil. I had just moved into the office, and, purely coincidentally, had just read an article on mycorrhiza fungus, and a highway project, and the difference it had made. Short version of the story (I'm leaving out the secret spray of the product in an evening, then openly declaring, next day, that no one had ever toasted the lawn gods with Irish whiskey, and made the partners come out to do it with me) was that there was a noticeable difference in seven days, and an outstanding difference in three weeks. I am convinced, totally, on the subject of mycorrhiza. I recommend Bio Vam only because it's the only product that I have used. I don't know if it's expensive, nor if it's cheap. It's the only one I have used. But I would seed the lawn, let it sprout, and spray the mycorrihiza. I would also fertilize with Milorganite, or some other sewage-based fertilizer product (there are several brands available on the East coast), as they won't burn the lawn. It's true you're going to lose some percentage of that seeded lawn. Fifty percent? Twenty Five? Ten? If you planted in the fall, you would also lose some percentage of that lawn. A lower percentage? Probably. But it's a function of how well you are able to keep the seed, and then those seedlings, moist but not wet. Keep the hose and nozzle moving, no puddling allowed. No puddles. But most new grass plants are lost when they're about the height of a dime (the ten cent coin) laying flat on the ground. At that height, they can dry out in an hour or two, less if there's a hot sunny, windy day. There's no root to let it grab moisture (the root hasn't grown yet) so there's no sense in any 'deep' watering. Just mist it. But if you do that, then when tomorrow gets here, that little plant will be a little more healthy, a little more tall, with a root a little more deep. And the next day. And the next day. Good luck with it. Here is a link that might be useful: Bio Vam mycorrhiza fungus

it's definitely not nutsedge, which has a different and distinctive look. first question to ask yourself:is it the exact same grass as the rest of your lawn? if it is, then extra water or fertilizer in that area is producing extra fast growth. If it's definitely a different plant, then you have a weed grass in there. I've had that. Big mess. Hard to get rid of. Good luck

I find this a disturbing thread, and a crime to the insinuation that the contractor is guilty of neglect. Did the OP consult with the contractor on the best way to enter the area where the patio was to be constructed? Was the OP willing to pay the cost of the additional time required to move all of that material by hand, or did he use the contractor who gave him the lowest price? We recently had a patio installed in our backyard next to our house. The patio took several yards of sand, some gravel, and six pallets of stone for the patio deck and the wall surrounding the 16'X20" patio. The contractor had to dig, the area down at one end to level the patio. There was the area where the dirt was placed prior to be removing from the property, there was the back fill area behind the wall. There would be multiple wheelbarrow loads to the back yard, for each trip with the that was made with the truck or skid steer. There would be multiple wheelbarrow loads move the pallets of stone from the front yard to the back. There would have been multiple wheelbarrow loads of sand and gravel. Then there is the removal of the dirt from the excavation. Does the OP think all of the trips with the wheelbarrow, and the slipping and sliding of the worker as he pushes the wheelbarrow through the wet area will leave no marks. I think the OP is being quite unrealistic to think this could be done without a mark or depression in his yard. I understand the OP frustration with restoring the yard. The day after they finished my patio, we got about 2' of rain. It was several weeks before they could get back to install the sod. During that time we had over 200 sqft of soup around the patio. The soup was so thick that some of the pavers I used to replace the path, slid across the soup. (Had to have some way of getting off the patio into the back yard). I had to rework the grades in some areas to reestablish the water flow. I still am working on the grass in the area, and the patio was installed a year ago.

Where in the United States are you? Have you had a good reliable soil test done? What is the soils pH? How much organic matter is in that soil? Have you talked with your states Cooperative Extension Service people about which grasses will do best in sun and which in shade in your area of the world? Aside from that good reliable soil test for pH and major nutrient levels perhaps these simple soil tests may be of some help. 1) Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. 2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drainsâ too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up. 3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart. 4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell. 5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.