Newly seeded lawn troubles :(
Hello! I need some advice. First a little background info on my very frustrating venture of seeding a new lawn. We live in lower Baldwin Co. AL, about 4 mi from the Gulf. Despite our best efforts to care for it, our approx 1200sf back yard was in terrible shape with more bare spots and weeds growing than grass. We do have dogs but I don't think they are the only reason the lawn failed. It was already looking pretty sad when we moved in in 2008. I believe that the contractors sodded the yard with some very low quality centipede grass back in 2005 when the house was built.
So, my husband and I have worked very hard to start the lawn anew. We killed off what was left growing back there, tilled and amended the soil, added 2-3 inches of fresh topsoil and then prepped with seed starting granular fertilizer. After tons of research, I decided on a mixture of seeds that I thought would work best for weather zone, high traffic and disease tolerance. ( I know, I know you might be thinking we prob should have just gone with sod in the first place. That might be so. But we already poured this much time, care and money into it at this point that I'm determined to see it through.) I paid pretty penny for some high quality Argentine Bahia seed. Also threw in some midnight KY bluegrass (supposedly more suited for the hot, humid south) because I do have one area that gets a good bit of shade.
My problem is that the yard is on a gentle slope and the weather did not cooperate one bit. Three days after the first seed application in April, we got really super abnormally heavy rains and most of the seed washed out (although it had been raked in and covered with a shallow layer of compost.) I waited about 12days or so to see what would come up, which was a big disappointment. So I re-ordered the Bahia, leveled out the several small gouges that the massive rainfall drainage carved out and reseeded again. Raked it in. Again. Spread a thin layer of compost over it. Again. And this time went over it all with sand in the spreader in efforts of holding the seed in place. Added a little straw on top for good measure. Sure enough, 2 days later came another all-day torrential downpour (the forecast was only calling for a 60% chance of light showers.) There was seed washout, but not as extensively as the first time. So I left it to grow, figuring I would surely have enough growth this time around. It has been on a regular daily watering schedule when there isn't rain.
So fast forward to now, over a month past the second seeding. It's in need of it's third mowing. There is good growth of what seed survived the washouts. The grass is in differing stages of life but still pretty tender for the most part. And it's sparse enough that I'm starting to see a good amount of weeds encroach. Grrrrr. Bahia isn't a quick spreading grass (I know now.) So I feel like I might need to put some more seed down? I'm just wondering how much (I have a few pounds left from last bag I bought) and how do I disturb the ground so that it has enough soil over it to germinate without damaging the young grass that is already there? Raking is out of the question. I have one of those spikey rolling aerators on a stick, but it is pretty destructive to the grass also. Any tips or input will be greatly appreciated!
P.S. I now have a really thick, beautiful, expensive stand of new grass mixed in with the weeds in the DITCH behind my privacy fence that separates my property from the woods! Lol, grrrrrr