Last fall, I did not get around to mowing my yard, after it was pretty tall. It was a pretty good looking, lush lawn. Now, in places, the lawn grows great, in others it does not. I can see obvious thatch beneath the grass. Everything I have read, says dethatch in late spring or fall. It is a little too much to do by hand, and alot of material is coming up. Should I NOT dethatch now, and wait until fall??? Also, I have heard after you dethatch to fertilize with a Nitrogen based fertilized (like 10-10-10). Any other suggestions??