By core aerating, you probably exposed weed seeds...

I doubt that you would see any poa seeds brought up germinating and growing that fast. However, you could be seeing poa that is just comming into its own that germinated last fall. It's hard to say what the problem is. Aeration is agressive and does damage roots. If you didn't use a cam style aerator, the tines will affect the surrounding turf roots as it pivots going in and out of the soil. The turf is just now comming out of dormancy and that may have an effect on color. I'm in N.E. Ohio near Akron/Canton, about 50 miles north of Pittsburg and I've noticed some light green areas throughout my lawn this Spring after my mowing. For me, this seems to be due to some sporadic scalpng. Evidently this winter with the variations in temp, I had a lot of frost heave. (rolling is in my near future)
I'd say fertilize after May 1 and see if it doesn't recover by Mid May. It should unless your poa problem has spread.

Ty I had already seen the normal poa pop up and the rest was deep green, so theres NO way that would happen that fast all the research i've done on poa and poa trivialis, all my neighbors have the same look on there lawns also, so I am thinking it was frost and walked on, if thats the case then I'm sure it should recover after it stays stable this awful weather here :/

We definitely had a hard frost a couple days ago (I was shocked at how much I had to scrape my car before going to work). If you had cut low(er) than you should (this time of year I bag cut as high as my mower goes to prevent/limit weeds and protect against potential frost damage), aerated it, and walked on it while it was frozen, it is possible you did some serious damage (not saying it's not recoverable just serious).

Ideally you'd give it a small dose of nitrogen, but I wouldn't since this is prime weed time and you don't want to be feeding them especially if your grass is weakened and not growing as fast.

Hi there, I didn't walk on it when there was frost persay but maybe the grass was still cold I aerated at 1 pm and it seemed like the perfect day to do so...Idk why it is all stressed now and light green and spotty :( I hope it recovers it is only april so I'm sure it will once it warms up in Pa and stays warm...should I cut it this upcoming weekend?? or let it go for now????? Thank you ;)

What height are you cutting at?
Are you following the 1/3 rule?
Have you put anything on it so far this year?
Pictures?

HI grass1950, I will take some pics tonite and show you, and Yes I only took off 1/2 inch and always mow my lawn at 2 1/2 inches, I keep it long so it chokes out weeds it was a sodded lawn back in 2009 Oct to be exact, so it has alot of rye and fescue, its a beautiful lawn or was :( I Hope it recovers well...

and yes I forgot to mention I put scotts crabgrass& fertilizer for the pre emergen effect on the poa, and I did it on labor day last yr too ...its in a few spots..but it looks normal in june/july and aug, just early spring the poa looks limeyy..which I know will blend in w/ the KBG late summer... :) Hope this helps

This was the color of it before sunday when I aerated, this pic was last spring of 2012 I didnt take any this yr..except the new one I am about to post I took tonite of the damage from the cold/frost I think.....what do you think?

This is what it now looks like :/

Can you get some closeups of the light patches?

I'm pretty comfortable in saying that that doesn't look like it is a result of aerating. It might still be comming out of dormancy. Hopefully tiemco can give you an answer.

but it was out of dormancy and deep green, the weather here in pa is nuts though, up and down, I can take some close ups today ....Thanks

I know this was a few years back but I had the same problem after we aerated our lawn a couple of weeks ago. Did it ever green up again?

Leah, eventually it does recover. Lisa is/was a special case of someone who will do anything and everything to cure any minor flaw in her garden. She used to post these pictures that anyone would be extremely proud of and point out some detail not to her liking. Well, two of her pictures are in this thread.

Anyway, you do not need to do core aeration. The lawn gurus on other forums have come up with a better way to do whatever you thought core aeration would cure. If you would start a new topic on Houzz and tell us what your lawn issues are, we can take off from there. Posting to Lisa's topic will not get you the attention you deserve. Be sure to tell us where you live when you post, as Lisa did with her initial post.

@dchall_san_antonio Lmao, BE NICE!!!!!!! Yes i'm super OCD with my Lawn, but Go easy! ahahahahahaha and Yes Leah, it recovered it was in shock I think, I can't remember this was 7 yrs ago, every yr its a new problem but that's what happens when you're OCD and have a nice lawn, things happen and I panic :)

@morpheuspa (6B/7A, E. PA) umm You're always nice!!!

I think there's one or two around here who might disagree. But then again, I tend to return the same currency I'm given. :-)

Yes, that was my nicest version of what I had written.

We're looking forward to seeing more lawn porn from you this season, Lisa. We wish we had trophy lawns like yours.