Sorry, I should've said "ideal" 60-70 deg. Up to 80deg is considered acceptable, but when it is that hot you really have to stay on top of the watering. But maybe out there it is really humid. Out here, 80deg means watering very frequently just to keep the ground wet. Once the seeds have gotten wet, if they let them dry out then they are toast. I also shouldn't have said late fall. I was thinking late Sept, which would be when temps are around 70F. In my experience, once the average daytime temp drops below 50, growth pretty much stops. That would be right around late Oct, and if they are like us, that is when everyone blows out their sprinklers for winter. Given the colder temps, full germination will be right around mid Oct, and by late Oct the new sprouts will be about 1" long. This means watering by hand for us, because even though it's cold, the new growth still needs to drink. IMO, that is really annoying, but I don't like to risk an early freeze damaging my sprinkler system. I don't have to worry about any of that when seeding in Apr. But to your other point, you can still seed in Apr even if the temps aren't quite high enough. They'll start to germinate as soon as the soil gets above 50-ish. And if the lot isn't shaded, soil temps reach 50 before air temp does. Anyway, I accept that Sept is the recommended "best" time to seed. My point is that early/mid spring is acceptable enough to go ahead and do it. If a person follows those steps, they will get perfectly acceptable results from a spring planting. I don't think there's any real compelling reason to wait until fall to overseed. Does it really matter if 20% fewer seeds germinate? Seed is really cheap and if a couple spots don't take, get them again in the fall.

Thanks for your reply. However, your psychic senses are wrong. I do tend to analyze things, especially when it's regarding a new endeavor/field I have no prior knowledge/experience of. It has yielded outstanding results for me in the past and so I continue to approach things in this manner. Regarding seeding too late - well, first off, I just took possession of the house so I couldn't seed earlier. Also, I live in Edmonton, Alberta Canada and if you've ever lived here, you would know that our summer is pretty much about 2 weeks long. lol Anyway, When I did the overseeding, it was about beginning of June and temperatures were about 10 C - 20 C and we've been getting a lot of rain lately. In fact, we're just starting to go up to highs of 20 C - 25 C and in about 5 days is the first day we're supposed to hit 29 C, as per the forecast. I know that Spring and Fall are the textbook times to overseed but our weather/termperatures here does not conform to the norm. Our temperatures in October are already winter temperatures for a lot of places in the States. Also, I did not want to wait until fall because I wanted to get started on thickening the lawn asap. I was confused with this statement though: "But you are just now coming into spring...and fall is just around the corner." Spring is technically done..did you mean, "just coming into summer"? I usually mow at around 4 -5 inches and only take a bit off. I know all about the "only take 1/3 off" and "mow high" recommendations. I only scalped it this one time to prepare for overseeding to facilitate better seed to soil contact. I've read about the roller thing but decided that it wasn't needed. I did not want to compact things any more either especially since I was core aerating. I ran my rake through the soil and seeds to enhance seed to soil contact and this is a technique that has been recommended in several articles and videos. I also did not want to bury the seeds too deep. In fact, I already have baby grass growing to about heights of 2 inches now. I only noticed them yesterday and they are even much taller today. I like your idea of sowing KBG first, then fescue then PRG but here's the thing - I have not found any stand alone seed packages in my local Walmart/Home Depot/Canadian Tire stores. They are all blends. I haven't gone to garden centers though but that's also because I do not want to pay more for something that sells less at Home Depot. Also, I think this says something.. I think that for our climate and grass types, the seed blends probably tend to work better. I think this is evidenced by the fact that I primarily see Scotts Sun and Shade being sold in all these places and not the other types - i.e. high traffic, high heat etc.. Also, this blend tends to get the best reviews on Canadian Tire.com. The other thing too is that I've read blends were made so that the PRG can germinate first and help establish the turf while the fescue and KBG are taking their sweet time to germinate - helps with thickening up lawn quicker and crowding out weeds. If I wanted to wait (or had the luxury to do so - i.e. lawn isn't too bare) the full 21-28 days, then I would probably just seed with pure KBG and not worry about blends. I've decided to wait with the dandelions. I've emailed Scotts and they said to wait after mowing the new grass 3 times before using Killex as it destroys grass seed and new grass. Just wondering why you say spot spraying is far better than broadcast anything. I just feel that if Killex is safe to use on an established lawn, it would be more efficient to just broadcast it, in terms of time and coverage. Regarding my neighbor's lawn - I'm not worried that her lawn looks like crap..I just feel that her dandelions are invading my lawn and I can see that most of the dandelions on my lawn are on the side close to hers. Anyway, I'm just gonna keep mowing high and hopefully it gets thick enough to crowd out weeds and hopefull I won't have too many dandelions and I'll just deal with them as they come.

Temps were in the low-mid 70s during day and low 50s at night when applied, only applied it in test areas, followed directions that stated to water down lawn before applying, lightly applied only in test areas (e.g., 2' x 2'), did not water for a couple of days after that (if I recall correctly it stated don't water after that so the granules stay stuck to the weeds). Believe me, I followed the directions. The only clue I had on the packaging about what may have happened is the fescue isn't established enough, although at least some of it should be considering it was planted from seed and thriving the summer of 2006, just some overseeding to fill in spring 2007. I think the packaging says don't apply until you've mowed new grass at least a few times but my lawn had been mowed many times more than that.

I am by far not an expert grass guy but I can give you some insight into what I have learned after starting 3 large lawn areas under less than ideal conditions. It sounds like you have done a great job so far. IMHO I would mow your grass will be 2 feet tall if you wait for it all to germinate and be 3" tall. Sure your going to crush/damage/kill some seedlings but how many are you going to lose if they are deprived of sunshine? Plus you will be stressing your existing grass by chopping too much off. The clippings, if anything, will help retain moisture for them. I try not to step on or roll over known seeded areas, sounds like this might be hard for you. I agree with waiting 8-10 mowings to broadcast spray. I have killed seedlings by jumping the gun. I personally would wait till fall. You could spot spray and will only risk killing seedlings with the over spray or, thanks to a user here, use a small paint brush and paint each one. I over seed my lawns every spring and fall. I broadcast spray with killex the day before I am going to seed. Watch home depot and the like in late fall. They usually blow out seeds and other gardening stuff at pennies on the dollar. One thing that really helped me and my lawns was buying a soil test kit. I test my soil about 3 times a year (spring, mid summer, fall) to find out what it is lacking and buy fertilizer to balance it out. I didn't realize my soil was very alkaline and after dropping the PH my lawn is doing WAY better. Good luck SCG