Question
QUESTION: Our lawn has been badly neglected, and I'd like to try to see more grass this
year.  We have large elms in our yard which provide great shade, however we
also get millions of tiny elm seedlings that sprout each summer.  The grass
under the trees is sparse. In the sunny areas we have been almost overrun
with nut grass and crabgrass.  We need to use a pre-emergent to keep some
of this under control but also need to reseed to get a fuller lawn.  When do we
do which one?  

Oh, Our Western Garden climate zone is 8.  Very hot summers that cool off at
night, very humid winters.

ANSWER: Hi there
 I think you should wait for April to reseed your lawn. Apply good seed like scott seeds. Use basal dose of NPK fertilizer along with seeds. Best of luck
Aman

---------- FOLLOW-UP ----------

QUESTION: Thanks for your prompt response!  Around here the seeding is usually done in
February because of the 11 month growing season.  Unfortunately all the
crabgrass, nut grass, and elm seedlings start growing at the same time.  So am I
understanding that I should put down pre-emergent in February and seed in
April?

Answer
Hi there
You should try herbicide named MSMA + Sedge hammer. these both are selective and repeat the spray after 15 days. This will resolve almost all your weed issue. I will suggest you to try Bermuda varieties as you told me about 11 month growing season. But if you have different variety presently then you need to eradicate it with round up other wise you will not get uniformity in your lawn.Ther should be minimum one month between spray and reseeding as round up has residual action in soil.

Aman