Question
I am located in Maryland west of baltimore with 1/2 acre yard.  This summer i decided to regrade my yard, previous owners never took care of it and it was so bumpy that it made it a real task to cut.  Anyway i regraded with a bunch of free fill dirt then tried to fertilize and seed just to get something there instead of dirt.  Most grass died off because of the hot weather.  Now all i have is crabgrass everywhere, it was probabbly everywhere before but not as noticeable because i had a lot of grass. I have plenty of seed left to reseed the whole yard, iwas wondering what i should do to get rid of crab grass and get a good looking lawn so i dont have to keep doing this.  The dirt i got seems ok, a little more clay than i would like but it was free so i cant really complain.  

Should i kill off the crabgrass and wait till spring to seed?  I was thinking of aerating, then seeding/fertilizing then in the early spring kill the crabgrass.  I was told fall is the best time to seed because the roots grow down in the colder months so i would get good roots, not sure if this is true.  I just want to get the crabgrass and weeds out so i get a nice looking lawn.   Should i test my soil to see what fertlizer i need?

any help is greatly appreciated.  

Answer
Kill the crabgrass and everything else with Round-Up (a weed and grass killer) now. Spray on calm day and avoid drifting to desireable plants and bushes or they will be damaged, too. Round-Up will kill existing plants and will not leave residue in the soil so you can seed immediately.

After weeds die, pull them and loosen top of soil. Then sow 4-6 lbs of grass seeds per 1000 sq feet and firm down well by tamping down by back or rake or by renting a landscapers roller (to ensure good soil/seed contact).

Until new seeds sprout, water daily to ensure the seed bed is consistently damp/moist. if the seeds are allowed to dry out just slightly, they die. After new grass is 2-3" tall then you can gradually change to an infrequent but deep watering pattern.

fertilize at time of seeding and again in late fall (after new grass is 3-4" tall and you have mowed).

Next year in early spring, apply a fertilizer w/crabgrass prevent (such as Scott's Turfbuilder with Halts). Apply to dry lawn and water in well immediately. apply no later than april 1st.

A good normal routine for your lawn would be:
- fertilize in late spring, early fall and late fall (in early spring also if you fight crabgrass)
- mow regularily and at the same height (2.5-3.5" tall)
- water infrequently and deeply such as once per week for 1 hour i/o daily except during seed establishment (must keep seedbed consistently damp/moist).

Good luck