Can you post a picture of it? I was recently surprised after seeing a yard that the owner claimed was rocks. It really was rocks. Usually (I think) "rocky soil" is more like what many of us have and live with. Get something growing. If it is weeds, fine, just get roots in the ground. Start watering right (below), mowing, and fertilizing. All that will do now is get roots growing and start the biological cycles that need to happen before you can really have a great lawn. Here is the basic, 123 of lawn care. Water deeply and infrequently. Deeply means at least an hour in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. If your grass looks dry before the month/week is up, water longer next time. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds. Mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. Bermuda, centipede, and bent grasses are the most dense when mowed at the lowest setting on your mower. Dense grass shades out weeds and uses less water when tall. Dense grass feeds the deep roots you're developing in 1 above. Fertilize regularly. I fertilize 4 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above. In your case, I would suggest starting with both compost (at 1 cubic yard per 1,000 square feet) and an organic fertilizer. The easiest and cheapest thing to find anywhere is alfalfa pellets. You can probably find soy bean meal, too. Both will come in 50-pound bags at the local feed store. Spread them at 10-20 pounds per 1,000 square feet. They are both organic fertilizers and will help your soil biology tremendously. You can apply those as often as you want and can afford all summer long. The more you apply the faster your soil will become better. You could also spray it with molasses and milk every other week. Mix them 50/50 in an Ortho hose end sprayer and set the dial for 3 ounces per gallon. Put about 3 ounces of mix onto every 1,000 square feet. Milk provides enzymes the soil microbes can use, and molasses helps feed them. Then in the fall you can decide how you want to proceed with synthetic fertilizers or with organics. But adding synthetic fertilizers now to a relatively sterile soil will prolong the benefit rather than speed it up. The organics will actually help even the worst soil. Coddling weeds all summer may seem futile but it is better than nothing. At least it will give you practice and you'll be surprised how nice mowed and fertilized weeds can look. Weeds can be eliminated pretty easily by several means, so don't get too worried about that. For that matter, Dutch white clover is considered a weed but it is very beneficial to the soil. You might find some clover seed and grow that all summer. Before you do anything in the fall, get a soil test so you know exactly how much of what to add. All this may be off, though, depending on the picture you post. You may really have to get rid of the rocks first.

It is very common for developers/builders to remove the top soil and sell it before they even pound one nail in any houses they are going to build. However, it is also very common for lawn guys to use this as the perfect excuse for why your lawn looks bad. Look around the neighborhood, do all the lawns look equally bad or is it just your house? It is likely that you have to have a few inches of top soil just maybe not as much as we would like. Depending on your budget you have a few options. If you don't have any budgetary concerns I would contact a reputable landscaper and have her put together a quote to install a new lawn with plenty of topsoil. You should get at least three estimates and have them hold off on the work until August. Spending that much money on an install in spring is a bad idea because you would have many weed and crabgrass issues. Any good landscaper could have you with a picture perfect lawn by September. Not all landscapers are good. The second option would be to continue to treat your lawn and attempt to build it slowly. You will need to have patience and a tolerance for some weeds. If there are bare areas or parts of the lawn that are thin I would suggest you make an attempt to seed them now, however, as I said before, seeding in the spring time is never particularly effective. Temperatures and competition from grassy weeds usually leave you with less than perfect results. If it is possible you should rent a core aerator (or hire someone to aerate) and then over seed the entire lawn with a mix that includes mostly improved rye grasses. (I am assuming your lawn is mostly sun and not a lot of shade) Rye grass will germinate faster than any other type of grass. (using bluegrass or tall fescue will result in about a month of waiting for the seed to germinate. Rye grass will come up quick) Make sure you water effectively if mother nature doesn't provide enough. It will be very important that you make a concerted effort to water properly and set your mower at the highest setting it will allow. Mow high all spring and summer to crowd out weeds and crabgrass. NEVER EVER mow your lawn during the heat of the day when temps are over 85 degrees. This is very important....do NOT mow your lawn during the heat of the day. Finally, you should get on some type of a program to help feed your lawn and your soil. A chemical program would be the easiest, cheapest and most convenient but probably not the most effective. (The tech you get treating your lawn will probably be a hard working person but not particularly knowledgeable and his/her goal is to sell you more stuff) With topsoil that is less than great you will want to improve it as best you can. Synthetic, chemical fertilizers won't do that although they may help your lawn to grow and be green. An organic program would slowly build your soil and promote some good biological activity below the grass. You should also look into compost tea. Remember; seed now, water effectively, mow HIGH, feed the soil and have patience!!!!! Good luck!!! Oh, by the way...stay away from corn gluten if your seeding.

@OP - You were getting a late start this year. Likely your lawn will still be covered with weeds this summer. I would encourage you to consider "Lawn Solarization". This process takes 4-6 weeks during the heat of the summer, and will kill all weeds, weed seed, and pathogens in your soil. The nice thing is, there is no chemical residue left over, so next fall when you do your overseed you will be in real good shape. One of the things I like about Organic lawn care, is that it forces you to think outside the box. It's easy to pickup a chemical weed spray, or manage a 4-step program... It takes soil knowledge and a buildup of healthy soil to successfully manage your lawn organically. I always tell people, if your really not into it, managing your lawn organically isn't going to work... Even when you are interested, it can be frustrating! That's why the vast majority of people go to the big box store and just throw around whatever they are selling... it takes effort to submit soil tests, analyze results, and apply compost/grains accordingly. This is my lawn, 6 years, no chemicals. Still not perfect, I have some problem areas, and keep learning more all the time.. but my neighbors finally "Get It".. They thought I was nuts when I told them I don't use per-emergence, weed n' feed, 4-step, ect... Lawn Solarization Instructions

I am not familiar with your area and what types of grass is grown and readily available, so I will let someone else comment on that. I seeded Bermuda, im in texas, about 2 years ago when my house was built. I started off with rye grass during the winter, but since it did not take everywhere, it resulted in areas where there were washouts. I did not level my lawn again before planting Bermuda, wish I would have, but it is not all that bad for me. I am currently taking my time in leveling the lawn now with a very good amount of grass. I am doing it in small sections as I have over 3/4 of an acre to maintain. So back to your situation and what I would do. If you think you have bad soil, maybe consider doing a soil test. While the soil test is being done, spray the area with round-up if you are trying to get rid of whatever you currently have. If you do not want to do that, then bring in topsoil, and then get someone to use a box blade to smooth the area and then seed whatever and whenever is recommended. I will strongly recommend not tilling. I have tilled in certain areas, where I though the ground was too hard to seed and it did result in a bumpy yard. Tilling also roots up new weeds that you currently do not have. If you do some searching here and other sites, you will see some good posts on leveling, prepping and seeding your yard. Hope that helps as a start for you. To keep this post short, I will try to answer anything else if you have specific questions.