I should probably tell you I live in the North East New York to be exact.

Killing everything sounds like the best thing you can do, it's called a total renovation in lawn-speak. A few things. You should have a soil test done as soon as possible. Umass has a good one for 13 dollars. This is very important, don't assume your soil is fine, if you're going to do it right, get the soil test. North East NY isn't really exact. A zip code would give us a better idea of where you are. Northern NY is generally Kentucky Bluegrass country, but only if your lawn gets 4 hours minimum of direct sun, and more would be better. KBG takes 2-3 weeks to germinate, so you really need to get moving if you are serious about this, and some might say you are a bit late to get started now. It's a lot of work, not a matter of just throwing seeds down and voila, instant grass. Those seeds need to be water 2-4 times per day, if they dry out, then they won't germinate. Your seeds ideally should be down mid to late August. To kill everything use Round up, or any product with Round-ups active ingredient, glyphosate. It will take two weeks for everything to turn completely brown and dead. Here's a few questions for you. How many square feet are you talking about? Does the lawn have shady areas? Is watering going to be an issue? How much time and effort are you willing to devote to this? Do you have someone to help you? Hope this helps.

Thank you for your detailed answers. My zip is 10573. I am actually on the border of Connecticut. My house is approximately 2000 sq ft and I have 1/3 acre property included, pretty good size front and back. I have 1 maple big old tree in front, and 1 the same in back. I would say a little less than half of the yard is shaded. Front gets morning sun. Back gets afternoon sun. I do not have a sprinkler system. I was actually thinking of putting one in, while undertaking this project. But as you say time is not on my side. I am borderline obsessive, so that will not be an issue,as far as time devoted. I can probably rent some machinery to assist in the heavy work. I am a huge fan of Kentucky Blue Grass. With you knowledge I will make this happen.

You have been a huge help. If you could give me a plan, I will follow to the letter. Much Thanks, jjbjr

So you actually live in southeast NY, Portchester. We are only about thirty miles apart. You can still go with KBG if you want, but the shade issues you have means cultivar selection is very important. 1/3 of an acre is a lot of area to cover, especially when you should be dropping seeds in about 3-4 weeks. It might be easier to do either the front or the back, but not both. If you do so I would recommend doing the back first so you can get your feet wet and learn from your mistakes for next year. Also once you get your soil test back (you sent that out already, right?) you can begin working on getting your soil ready in the front for next fall. I know it's hard to wait a whole year, but grass renovations are marathons, not sprints. Also, a sprinkler system will make it much easier to keep your seeds wet, but it's not necessary. If you decide to get one, time is of the essence. Since the clock is ticking here's what I would do: Soil tests today if you haven't already done them. Round-up the areas you are going to do tomorrow, but once you do that, there's no turning back. Schedule the sprinkler system to be put in a week after the Round-up (if you are going to do that). When everything is brown and dead, mow it as low as you possible can, using the bagger attachment to get all the dead grass up. Then I like to core aerate, north-south, then east-west. Follow this with a good power raking. This will break up the cores, fill in the holes and break up the remaining dead grass. After this (if your arms haven't fallen off) then a final manual raking will smooth is all out and you can remove any dead loose grass. Now it's time to seed. Use a rotary spreader. Apply half the seeds in a north/south direction, the other half east/west. Shoot for the middle to lower seeding rate, don't think more seed is better. More seed equals trouble. Use a water filled roller to press the seeds into the soil. Now you can top dress with a very thin (1/8") layer of peat moss or fine topsoil or compost, but it's not entirely necessary. Apply some starter fertilizer (I use half the recommended rate) and then keep it all moist (not wet) for three weeks. This usually entails 2-4 five or ten minute waterings every day. No one, kids or pets, can use the yard for at least two months, another good reason to do the front and back separately.

Soil sample is going out today.When I get ready to seed I will ask which seed is best. I like the Idea of doing the back first.Thanks.jjbjr

Great. Please tell me about your backyard in more detail. The shady areas, how much direct sun do they get on a sunny day? How much sun do the sunny areas get on a given day? Is it fairly level? You might have to add some fine fescue if you have deep shade.

Hello tiemco,
Ive been following this discussion since I am very unhappy with whats going on with my lawn. Seems as though some weak grasses have thrived and the summer hasnt helped. I have some photos. I noticed you said 'more seed is not better, in fact more seed can cause trouble'. One of my suspicions is that I overseeded too heavily and my lawn is being suffocated. maybe you can tell by the photo? Thanks for having a look. I originally put down a mix of KBG, RYE and tall or creeping fescue. Seems like only one has dominated and I dont know which, but I dont like it. Too thin, yet very dense. Thanks

Here is a link that might be useful: photos

Hey ms, looked at your pics. Seems like you have a lot of fine fescue in your lawn. Yes, too much seed can result in no germination, or too much germination, creating very thick grass that stays wet for long periods of time, gets no air circulation, and gets matted after rains. This often leads to disease. From the looks of it most of your yard is full sun. Is this true? If so then fine fescue isn't the best choice, even in a mix. Save them for shady areas. It's better to shoot for the low end of a seeding rate, especially in grass that can fill in like KBG or even TF that tillers aggressively and has some spreading power. That way the grass will have plenty of room when it is young and more susceptible to disease and stress. As it matures it will fill in by itself, and will stop when it is getting too crowded.

Hi Tiemco
Thanks for your input. Would you know if there is a method to reduce the amount of FF in my lawn, so that soon I can overseed with KBG and get ready for next season? Id rather not just do a massive kill if I dont have to. Also, could there be something about my soil that makes it more conducive to a crop of FF then KBG. I used a mix, but it seems like an overwhelming majority is FF. Thanks

Outside of using certain herbicides there are a few things you can do manually. Instead of trying to remove one type of grass, a general thinning of the lawn will remove some of the grass you have and expose more soil so your overseed will be successful. Plus if you remove say 50% of the grass and it is 80% FF, then you will be removing a lot more FF than KBG. Thinning a lawn can be as simple as a good raking with a leaf or dethatching rake, to a good core aeration followed by a power raking with the tines set to remove some grass, or a combination of the two. I am sure KBG and FF prefer their "ideal" soils, but the difference between the ideals is probably small. You should get a soil test now to see what is going on in your soil if you plan on overseeding. What I suspect happened is your FF germinated first, and you cut down on the watering as the FF came in, thus hurting the growth of the KBG seedings enough to cause a good deal of them to die. If you seeded at a rate that was above the recommended maximum then this could have also hurt the KBG as well. I would go with straight KBG this time around, using some shade tolerant cultivars if you have areas that get the minimum amount of sun for KBG.