Question
In my area of michigan spring time bring about an avalanche of those twirling tree seeds that fall everywhere. I just put in a new lawn from seed and the tree seeds fell in the yard as well. Naturally I could not rake them out without disturbing the new seed. Now I have tiny tree saplings growing in my grass. Dozens of them. What is the best method of getting rid of them without harming my grass which is about 4 weeks old now?

Answer
no doubt you are fighting seeds(double winged) from maple trees.
you could handpull the little maples. they will come out easy.
or just keep cutting your lawn weekly(2-3" height). the maple trees will out grow the grass so that when you cut weekly you will eventually weaken them and they will die off.