I had quite a bit of fill brought in (70+ loads) for a garage build project in the northeast (zone 6 climate). This gave me much more yard so I had planned on planting new grass. I brought in over 10 truck loads of topsoil and spread it out, then went over everything with a rock hound.
For the seeding part, I looked into sod as well as hydraseed. As good as they sounded, I didn't have it in the budget as I was already way over budget with the project. I went and bought the best grass seed (P5 Banfield & Baker) that everyone was telling me to get. I laid out the seed, fertilizer, and then put Penn mulch down.
Grass started to grow after a week. I would do my best to water every day although we had some really hot 80+ degree days and the water didn't stay saturated in the soil the entire time.
Because I had a lot of area to cover (estimate 15-20K sq ft), I seeded in sections over a 2-4 week period.
Initially it looked like the grass was coming in nicely.. but after 3-4 weeks, the grass was not thick or lush. I will admit that I probably didn't put enough seed down as I still had quite a bit of seed left over at the end (I started with 2 50lb bags).
I planted the seed back in mid May and it's been about 2 months and while it looks like there's grass, the grass is pretty thin and it hasn't grown enough for me to even mow it. With some of the hot days we've had, the grass even started to turn yellow/brown.
In some areas where the seed eroded and settled into certain areas - that grass is green and tall. So I imagine I didn't use enough seed. But in other areas where I used the same seed setting on the spreader, where the topsoil always stayed black color and wet looking, that seed is grown so much I've had to mow it already.
Looking to consult with the experts to see how I can fix at this point... One thought was to just loosen up the existing soil after a good rain and overseed.. I tried that in a small area a week ago to see what would happen but not a lot of time has passed to see if it's working.