I disagree with Auteck's recommendation, and I'm a little surprised he recommended what he did. Your original grass seed mix selection was tall fescue, fine fescues and KBG. I suspect you have mostly tall fescue growing since you have bare spots. If the KBG in your original grass mix had germinated fully, then it should fill in bare areas in the sunnier parts of your lawn. I agree with him in that perennial rye is usually what is grown in your area, but there was no perennial rye in that original mix. Overseeding your lawn with it now will give you some throughout the whole lawn, but the bare spots will be all PR, and they will stand out against the TF you have now. My advice, use either all TF to overseed, or a mix that has similar percentages to your original mix. I would also stick with Pennington's as it is usually the best mix in the big box stores.

When should i Round up the lawn? It all depends on when you are going to drop seed, and if you are going to fallow for a bit. In actuality you can round up a few hours before you lay seed, but that isn't too practical for home lawns. For a home lawn, 2 weeks is probably the least amount of time I would suggest, since after about a week you should know if you missed any areas, and you can reapply. Also when applying it, it is important that everything is green and growing. Dormant, or sluggish grass/weeds won't absorb it, and they can wake up during the renovation. So most people recommend watering a few times a week before you apply round-up, and afterwards as well. Which type of RU? I saw blue and green cap ones. Just use the straight round up or any brand that has glyphosate as the main ingredient (I use Ortho's from Home Depot, it's a little cheaper). The other kind has another chemical that makes things turn brown in a few days, but I don't see the need for it when renovating, plus it costs more. Should i drop the Calcium lime before i drop seed or after? Drop Potassium sulfate before or after? Your next liming should be 90 days after the one you did this spring. If that coincides with seeding then I would wait till your grass has been mowed a few times. When seeding I would use a half app of starter fertilizer at the time of seeding, and the other half after it has been mowed once or twice. So then lime 2 weeks after that starter app. The starter is high in K, so that will count towards a K app. Would it be smart to fallow the lawn? It's not a bad idea, especially if your weed pressure is/was high and you don't mind having a brown lawn for a month or so. Better to do a TTFF/KBG lawn or just KBG? It all depends on you and your lawn. If you have a good amount of shade, TTTF is going to do better. KBG makes the best lawn in my opinion, but it has a longer establishment and maturity time, so don't expect a full KBG lawn to be really nice next spring. It really hits it stride in its third year. TTTF/KBG is a nice compromise, but there can be some issues with color matching and growth rates. For the TTTF cultivars, those are all good. I would definitely use Bullseye, it is one of the best. LS 1200 is good, but it does poorly in shade. For the KBG: Bedazzeled: A good choice, not too dark, good spring green up, not sure about it's disease tolerance. Prosperity: A very dark cultivar, might not blend well with TTTF due to color, but I can't say for sure. It also has some disease issues, might not be the best if you are just using one in a mix. Moonlight 2: Not sure about this one, check the NTEP's and it's tech sheet. Emblem: Not a good choice. Seed on the market is old as it's being discontinued. A very aggressive cultivar, might dominate lawn. Also very dark. Has a very long dormancy period as well, i.e. slow spring green up. Blueburry: One of the darkest cultivars you can get. Might not blend well, and it might have disease issues. Moonlight SLT: A good cultivar, supposed to have some shade tolerance. Check the NTEP and tech sheet for mixability. Award: A compact midnight, so it's going to be dark, and might not blend well. Does OK in shadier sights, but not great. There are a few others to look at. Bewitched: A dark cultivar so be warned, but does well in shadier areas, not too aggressive, and has good disease tolerances. Unique and Apollo. Not as dark as some, good shade tolerances. America: An old standard, has been around for a long time, but still performs well. Has some shade tolerance, not as dark as others. Orfeo: A very fast one to germinate and establish. Blends well with TTTF, but is aggressive, so it can take over. In reality, color might not be as big an issue as I make it out to be as KBG really needs good soil high in iron to reach it's full potential while TTTF seems to be less finicky to iron levels. Many of the growers say a lot of their cultivars blend well with TTTF. If you are really worried about it though, then just go with all TTTF or KBG.

As to your original question: Many have had satisfying results from overseeding in the Fall. Success primarily depends on sunlight reaching the seed and proper irrigation for the 3-4 weeks that it takes for KBG to germinate. As would be expected, seed will take best in bare and thinner areas of the lawn. (keep in mind the need to match growth rates, color, and blade width between the new seed and the existing turf). I, personally have had very good results from overseeding. So, in my opinion overseeding works and is worth it, but results will vary. What puzzles me about your sittuation is what condition your condition is? It sounds like your major issue is loss due to disease. People particularly in the East are reporting increased brown patch issues this year with their TTTF lawns. To avoid brown patch damage you need to be proactive with preventative fungacides and reactive with curative fungacides. Brown patch usually (but not always) does permanent damage to the turf and as I said, TF doesn't possess the ability to spread and fill in in the Fall. So I'm a bit puzzled by what you are reporting. Anyway, the best thing to do about reoccuring disease problems is a preventative and currative fungicide regiment. Weak grass is more susceptable to disease, so you should see if there are any weak links. Get a soil test and see if you are low on any nutrients. The greatest improvement in turf will come from proper mowing, irrigation and fertilization.Make sure your turf is getting proper irrigation. Too much irrigation can be worse than too little, Do a screw-driver test to see if moisture is penetrating (poor water penetration (hydrophobia) can often be repaired by shampooing) If your soil is not holding moisture--add organic matter. What types of fertilizer are you using and what schedule? How often are you mowing and what height?

I am finalizing my plans for overseeding. I have decided to rent a slice seeder for overseeding. Anyone have any advice before I do? I assume I need to flag my sprinkler heads and avoid them? Seed of choice for this year is: I broadcast sprayed yesterday with a good amount of 2D4. Any other suggestions? I have a particular weed that I can seem to get rid of, I'll follow up later with a few pics of this weed for advice. It's a clump of crab grass that has migrated all over the front yard.