John...the good news is that even though the lawn looks a little rough....it may still fill in as things start to warm....but you may want to do to "go over" on any large bare spots NOW as spring is the next best to fall when it comes to grass.....you can pretty much let it do its thing...if you wait till summer you will only end up watering it like a mad man (and lord knows you dont want to waste time in the fall
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I also want to add that some grass seed mixtures contain larger percentages of annual grasses (used for "quick" fill ins) and wont come back after the winter....make sure you get a good mix with a high percentage of perrenial seed in it....