It could be a simple as more shade in the back which might require a different type of grass or different care.

If you use RoundUp to kill the grass, you should come through and rake the dead stuff out before seeding. If you are concerned about your back raking a large area you can rent a power rake, verticutter, or slit seeder. These machines have vertical cutting blades and can be adjusted to just slice the top of the soil. The machine will chew up all the dead foliage and you can rake or blow it away into a compost pile. Then you can seed right on top of that.

I suggest using a roller after seeding to ensure good contact between the seed and the soil. Then water it 3x per day for about 5 - 10 minutes each time just to keep the seed moist.

The good grasses for NY are the fescues (which germinate in 2 weeks), Kentucky bluegrass (germinates in 3 weeks), and/or rye grass (germinates in 1 week). If you get a mix of grasses be sure to water 3x daily long enough to get the slowest germinating seed to germinate. Once you have 80 of the seed germinated, then you can start to back off on the frequency and move up on the duration. Ideally a mature lawn will get a full inch of water per week, all at one time, during the hottest heat of summer. The rest of the year you can adjust the frequency to 2 weeks, 3 weeks and 4 weeks but keep the timing to deliver a full inch.

KBG is a great grass for full sun. I goes dormant in winter and can go dormant during severe heat in the summer. KBG will spread all by itself without reseeding every year.

Fescue is a great grass in sun and can tolerate some shade. It does not go dormant. It becomes more dense with annual overseeding for the thin areas in the fall.

Rye is a full sun type grass and needs annual reseeding to remain dense.

Unless you need to change your drainage, you don't need new soil. You can repair your soil easily with at least one application per year of organic fertilizer. My favorite organic fertilizer is straight alfalfa pellets (rabbit chow). Cost is about $12.50 for a 50-pound bag. Apply at 20 pounds per 1,000 square feet. I like it because it works and because it costs a lot less to use than commercially bagged organic fertilizers.

Thanks for the response....lots of useful information in there.

I sensed using the roundup isn't they way you would go. If you don't mind me asking how would you go about doing it?

Thanks again.

For a full yard reno I probably would use RU. I would fertilize with organics, water daily for a few minutes for a week, spray the RU (do not mow first), stop the watering, let everything die, scalp it out with a mower and remove, water daily again to germinate any weed seeds that did not germinate before, spot spray the RU to get those few new weeds, wait a few days, and then seed. Seed would be a mix of KBG and fescue from an online dealer who can provide seed with 0.00 weed and 0.00 other crop in the analysis. Then roll the seed down with a water roller, water the seed 3x per day for 5 minutes to keep it moist, and continue that for 3 weeks to get the KBG to germinate. Then back off on watering frequency and increase the watering depth. And always use organic fertilizer like alfalfa pellets.

If your backyard problems are not due to shade or irrigation, I would suggest you invest in a soil test done by a reputable lab.

dchall,

Thanks again...this will be the method I follow. I hope you don't mind maybe answering some questions for me once I start my project. I'm still not sure whether to start at the end of august or more towards beginning to middle of September.

Grass1950,

Thanks for the suggestion. Your probably right, it would make sense to get a test done before I begin. I'd rather do it right the first time.

Start as soon as the summer heat breaks. For you that could be late Aug to mid Sept. What you need is time for the grass to get established before winter hits. KBG takes 3 full weeks to germinate and it would be nice to have as many weeks at least to get it growing and mowed.

The seed with no weeds will cost more, even online. You really do get what you pay for with seed.

Are there any suggestions on what seed to buy and where to buy them?

I will post before and after pics along the way once I start.